| /* Common target dependent code for GDB on ARM systems. |
| Copyright 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1998, 1999, 2000, |
| 2001, 2002 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include <ctype.h> /* XXX for isupper () */ |
| |
| #include "defs.h" |
| #include "frame.h" |
| #include "inferior.h" |
| #include "gdbcmd.h" |
| #include "gdbcore.h" |
| #include "symfile.h" |
| #include "gdb_string.h" |
| #include "dis-asm.h" /* For register flavors. */ |
| #include "regcache.h" |
| #include "doublest.h" |
| #include "value.h" |
| #include "arch-utils.h" |
| #include "solib-svr4.h" |
| |
| #include "arm-tdep.h" |
| #include "gdb/sim-arm.h" |
| |
| #include "elf-bfd.h" |
| #include "coff/internal.h" |
| #include "elf/arm.h" |
| |
| #include "gdb_assert.h" |
| |
| static int arm_debug; |
| |
| /* Each OS has a different mechanism for accessing the various |
| registers stored in the sigcontext structure. |
| |
| SIGCONTEXT_REGISTER_ADDRESS should be defined to the name (or |
| function pointer) which may be used to determine the addresses |
| of the various saved registers in the sigcontext structure. |
| |
| For the ARM target, there are three parameters to this function. |
| The first is the pc value of the frame under consideration, the |
| second the stack pointer of this frame, and the last is the |
| register number to fetch. |
| |
| If the tm.h file does not define this macro, then it's assumed that |
| no mechanism is needed and we define SIGCONTEXT_REGISTER_ADDRESS to |
| be 0. |
| |
| When it comes time to multi-arching this code, see the identically |
| named machinery in ia64-tdep.c for an example of how it could be |
| done. It should not be necessary to modify the code below where |
| this macro is used. */ |
| |
| #ifdef SIGCONTEXT_REGISTER_ADDRESS |
| #ifndef SIGCONTEXT_REGISTER_ADDRESS_P |
| #define SIGCONTEXT_REGISTER_ADDRESS_P() 1 |
| #endif |
| #else |
| #define SIGCONTEXT_REGISTER_ADDRESS(SP,PC,REG) 0 |
| #define SIGCONTEXT_REGISTER_ADDRESS_P() 0 |
| #endif |
| |
| /* Macros for setting and testing a bit in a minimal symbol that marks |
| it as Thumb function. The MSB of the minimal symbol's "info" field |
| is used for this purpose. This field is already being used to store |
| the symbol size, so the assumption is that the symbol size cannot |
| exceed 2^31. |
| |
| MSYMBOL_SET_SPECIAL Actually sets the "special" bit. |
| MSYMBOL_IS_SPECIAL Tests the "special" bit in a minimal symbol. |
| MSYMBOL_SIZE Returns the size of the minimal symbol, |
| i.e. the "info" field with the "special" bit |
| masked out. */ |
| |
| #define MSYMBOL_SET_SPECIAL(msym) \ |
| MSYMBOL_INFO (msym) = (char *) (((long) MSYMBOL_INFO (msym)) \ |
| | 0x80000000) |
| |
| #define MSYMBOL_IS_SPECIAL(msym) \ |
| (((long) MSYMBOL_INFO (msym) & 0x80000000) != 0) |
| |
| #define MSYMBOL_SIZE(msym) \ |
| ((long) MSYMBOL_INFO (msym) & 0x7fffffff) |
| |
| /* Number of different reg name sets (options). */ |
| static int num_flavor_options; |
| |
| /* We have more registers than the disassembler as gdb can print the value |
| of special registers as well. |
| The general register names are overwritten by whatever is being used by |
| the disassembler at the moment. We also adjust the case of cpsr and fps. */ |
| |
| /* Initial value: Register names used in ARM's ISA documentation. */ |
| static char * arm_register_name_strings[] = |
| {"r0", "r1", "r2", "r3", /* 0 1 2 3 */ |
| "r4", "r5", "r6", "r7", /* 4 5 6 7 */ |
| "r8", "r9", "r10", "r11", /* 8 9 10 11 */ |
| "r12", "sp", "lr", "pc", /* 12 13 14 15 */ |
| "f0", "f1", "f2", "f3", /* 16 17 18 19 */ |
| "f4", "f5", "f6", "f7", /* 20 21 22 23 */ |
| "fps", "cpsr" }; /* 24 25 */ |
| static char **arm_register_names = arm_register_name_strings; |
| |
| /* Valid register name flavors. */ |
| static const char **valid_flavors; |
| |
| /* Disassembly flavor to use. Default to "std" register names. */ |
| static const char *disassembly_flavor; |
| /* Index to that option in the opcodes table. */ |
| static int current_option; |
| |
| /* This is used to keep the bfd arch_info in sync with the disassembly |
| flavor. */ |
| static void set_disassembly_flavor_sfunc(char *, int, |
| struct cmd_list_element *); |
| static void set_disassembly_flavor (void); |
| |
| static void convert_from_extended (void *ptr, void *dbl); |
| |
| /* Define other aspects of the stack frame. We keep the offsets of |
| all saved registers, 'cause we need 'em a lot! We also keep the |
| current size of the stack frame, and the offset of the frame |
| pointer from the stack pointer (for frameless functions, and when |
| we're still in the prologue of a function with a frame). */ |
| |
| struct frame_extra_info |
| { |
| int framesize; |
| int frameoffset; |
| int framereg; |
| }; |
| |
| /* Addresses for calling Thumb functions have the bit 0 set. |
| Here are some macros to test, set, or clear bit 0 of addresses. */ |
| #define IS_THUMB_ADDR(addr) ((addr) & 1) |
| #define MAKE_THUMB_ADDR(addr) ((addr) | 1) |
| #define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1) |
| |
| static int |
| arm_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe) |
| { |
| return (chain != 0 && (FRAME_SAVED_PC (thisframe) >= LOWEST_PC)); |
| } |
| |
| /* Set to true if the 32-bit mode is in use. */ |
| |
| int arm_apcs_32 = 1; |
| |
| /* Flag set by arm_fix_call_dummy that tells whether the target |
| function is a Thumb function. This flag is checked by |
| arm_push_arguments. FIXME: Change the PUSH_ARGUMENTS macro (and |
| its use in valops.c) to pass the function address as an additional |
| parameter. */ |
| |
| static int target_is_thumb; |
| |
| /* Flag set by arm_fix_call_dummy that tells whether the calling |
| function is a Thumb function. This flag is checked by |
| arm_pc_is_thumb and arm_call_dummy_breakpoint_offset. */ |
| |
| static int caller_is_thumb; |
| |
| /* Determine if the program counter specified in MEMADDR is in a Thumb |
| function. */ |
| |
| int |
| arm_pc_is_thumb (CORE_ADDR memaddr) |
| { |
| struct minimal_symbol *sym; |
| |
| /* If bit 0 of the address is set, assume this is a Thumb address. */ |
| if (IS_THUMB_ADDR (memaddr)) |
| return 1; |
| |
| /* Thumb functions have a "special" bit set in minimal symbols. */ |
| sym = lookup_minimal_symbol_by_pc (memaddr); |
| if (sym) |
| { |
| return (MSYMBOL_IS_SPECIAL (sym)); |
| } |
| else |
| { |
| return 0; |
| } |
| } |
| |
| /* Determine if the program counter specified in MEMADDR is in a call |
| dummy being called from a Thumb function. */ |
| |
| int |
| arm_pc_is_thumb_dummy (CORE_ADDR memaddr) |
| { |
| CORE_ADDR sp = read_sp (); |
| |
| /* FIXME: Until we switch for the new call dummy macros, this heuristic |
| is the best we can do. We are trying to determine if the pc is on |
| the stack, which (hopefully) will only happen in a call dummy. |
| We hope the current stack pointer is not so far alway from the dummy |
| frame location (true if we have not pushed large data structures or |
| gone too many levels deep) and that our 1024 is not enough to consider |
| code regions as part of the stack (true for most practical purposes). */ |
| if (PC_IN_CALL_DUMMY (memaddr, sp, sp + 1024)) |
| return caller_is_thumb; |
| else |
| return 0; |
| } |
| |
| /* Remove useless bits from addresses in a running program. */ |
| static CORE_ADDR |
| arm_addr_bits_remove (CORE_ADDR val) |
| { |
| if (arm_apcs_32) |
| return (val & (arm_pc_is_thumb (val) ? 0xfffffffe : 0xfffffffc)); |
| else |
| return (val & 0x03fffffc); |
| } |
| |
| /* When reading symbols, we need to zap the low bit of the address, |
| which may be set to 1 for Thumb functions. */ |
| static CORE_ADDR |
| arm_smash_text_address (CORE_ADDR val) |
| { |
| return val & ~1; |
| } |
| |
| /* Immediately after a function call, return the saved pc. Can't |
| always go through the frames for this because on some machines the |
| new frame is not set up until the new function executes some |
| instructions. */ |
| |
| static CORE_ADDR |
| arm_saved_pc_after_call (struct frame_info *frame) |
| { |
| return ADDR_BITS_REMOVE (read_register (ARM_LR_REGNUM)); |
| } |
| |
| /* Determine whether the function invocation represented by FI has a |
| frame on the stack associated with it. If it does return zero, |
| otherwise return 1. */ |
| |
| static int |
| arm_frameless_function_invocation (struct frame_info *fi) |
| { |
| CORE_ADDR func_start, after_prologue; |
| int frameless; |
| |
| /* Sometimes we have functions that do a little setup (like saving the |
| vN registers with the stmdb instruction, but DO NOT set up a frame. |
| The symbol table will report this as a prologue. However, it is |
| important not to try to parse these partial frames as frames, or we |
| will get really confused. |
| |
| So I will demand 3 instructions between the start & end of the |
| prologue before I call it a real prologue, i.e. at least |
| mov ip, sp, |
| stmdb sp!, {} |
| sub sp, ip, #4. */ |
| |
| func_start = (get_pc_function_start ((fi)->pc) + FUNCTION_START_OFFSET); |
| after_prologue = SKIP_PROLOGUE (func_start); |
| |
| /* There are some frameless functions whose first two instructions |
| follow the standard APCS form, in which case after_prologue will |
| be func_start + 8. */ |
| |
| frameless = (after_prologue < func_start + 12); |
| return frameless; |
| } |
| |
| /* The address of the arguments in the frame. */ |
| static CORE_ADDR |
| arm_frame_args_address (struct frame_info *fi) |
| { |
| return fi->frame; |
| } |
| |
| /* The address of the local variables in the frame. */ |
| static CORE_ADDR |
| arm_frame_locals_address (struct frame_info *fi) |
| { |
| return fi->frame; |
| } |
| |
| /* The number of arguments being passed in the frame. */ |
| static int |
| arm_frame_num_args (struct frame_info *fi) |
| { |
| /* We have no way of knowing. */ |
| return -1; |
| } |
| |
| /* A typical Thumb prologue looks like this: |
| push {r7, lr} |
| add sp, sp, #-28 |
| add r7, sp, #12 |
| Sometimes the latter instruction may be replaced by: |
| mov r7, sp |
| |
| or like this: |
| push {r7, lr} |
| mov r7, sp |
| sub sp, #12 |
| |
| or, on tpcs, like this: |
| sub sp,#16 |
| push {r7, lr} |
| (many instructions) |
| mov r7, sp |
| sub sp, #12 |
| |
| There is always one instruction of three classes: |
| 1 - push |
| 2 - setting of r7 |
| 3 - adjusting of sp |
| |
| When we have found at least one of each class we are done with the prolog. |
| Note that the "sub sp, #NN" before the push does not count. |
| */ |
| |
| static CORE_ADDR |
| thumb_skip_prologue (CORE_ADDR pc, CORE_ADDR func_end) |
| { |
| CORE_ADDR current_pc; |
| /* findmask: |
| bit 0 - push { rlist } |
| bit 1 - mov r7, sp OR add r7, sp, #imm (setting of r7) |
| bit 2 - sub sp, #simm OR add sp, #simm (adjusting of sp) |
| */ |
| int findmask = 0; |
| |
| for (current_pc = pc; |
| current_pc + 2 < func_end && current_pc < pc + 40; |
| current_pc += 2) |
| { |
| unsigned short insn = read_memory_unsigned_integer (current_pc, 2); |
| |
| if ((insn & 0xfe00) == 0xb400) /* push { rlist } */ |
| { |
| findmask |= 1; /* push found */ |
| } |
| else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR |
| sub sp, #simm */ |
| { |
| if ((findmask & 1) == 0) /* before push ? */ |
| continue; |
| else |
| findmask |= 4; /* add/sub sp found */ |
| } |
| else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */ |
| { |
| findmask |= 2; /* setting of r7 found */ |
| } |
| else if (insn == 0x466f) /* mov r7, sp */ |
| { |
| findmask |= 2; /* setting of r7 found */ |
| } |
| else if (findmask == (4+2+1)) |
| { |
| /* We have found one of each type of prologue instruction */ |
| break; |
| } |
| else |
| /* Something in the prolog that we don't care about or some |
| instruction from outside the prolog scheduled here for |
| optimization. */ |
| continue; |
| } |
| |
| return current_pc; |
| } |
| |
| /* Advance the PC across any function entry prologue instructions to |
| reach some "real" code. |
| |
| The APCS (ARM Procedure Call Standard) defines the following |
| prologue: |
| |
| mov ip, sp |
| [stmfd sp!, {a1,a2,a3,a4}] |
| stmfd sp!, {...,fp,ip,lr,pc} |
| [stfe f7, [sp, #-12]!] |
| [stfe f6, [sp, #-12]!] |
| [stfe f5, [sp, #-12]!] |
| [stfe f4, [sp, #-12]!] |
| sub fp, ip, #nn @@ nn == 20 or 4 depending on second insn */ |
| |
| static CORE_ADDR |
| arm_skip_prologue (CORE_ADDR pc) |
| { |
| unsigned long inst; |
| CORE_ADDR skip_pc; |
| CORE_ADDR func_addr, func_end = 0; |
| char *func_name; |
| struct symtab_and_line sal; |
| |
| /* If we're in a dummy frame, don't even try to skip the prologue. */ |
| if (USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (pc, 0, 0)) |
| return pc; |
| |
| /* See what the symbol table says. */ |
| |
| if (find_pc_partial_function (pc, &func_name, &func_addr, &func_end)) |
| { |
| struct symbol *sym; |
| |
| /* Found a function. */ |
| sym = lookup_symbol (func_name, NULL, VAR_NAMESPACE, NULL, NULL); |
| if (sym && SYMBOL_LANGUAGE (sym) != language_asm) |
| { |
| /* Don't use this trick for assembly source files. */ |
| sal = find_pc_line (func_addr, 0); |
| if ((sal.line != 0) && (sal.end < func_end)) |
| return sal.end; |
| } |
| } |
| |
| /* Check if this is Thumb code. */ |
| if (arm_pc_is_thumb (pc)) |
| return thumb_skip_prologue (pc, func_end); |
| |
| /* Can't find the prologue end in the symbol table, try it the hard way |
| by disassembling the instructions. */ |
| |
| /* Like arm_scan_prologue, stop no later than pc + 64. */ |
| if (func_end == 0 || func_end > pc + 64) |
| func_end = pc + 64; |
| |
| for (skip_pc = pc; skip_pc < func_end; skip_pc += 4) |
| { |
| inst = read_memory_integer (skip_pc, 4); |
| |
| /* "mov ip, sp" is no longer a required part of the prologue. */ |
| if (inst == 0xe1a0c00d) /* mov ip, sp */ |
| continue; |
| |
| /* Some prologues begin with "str lr, [sp, #-4]!". */ |
| if (inst == 0xe52de004) /* str lr, [sp, #-4]! */ |
| continue; |
| |
| if ((inst & 0xfffffff0) == 0xe92d0000) /* stmfd sp!,{a1,a2,a3,a4} */ |
| continue; |
| |
| if ((inst & 0xfffff800) == 0xe92dd800) /* stmfd sp!,{fp,ip,lr,pc} */ |
| continue; |
| |
| /* Any insns after this point may float into the code, if it makes |
| for better instruction scheduling, so we skip them only if we |
| find them, but still consider the function to be frame-ful. */ |
| |
| /* We may have either one sfmfd instruction here, or several stfe |
| insns, depending on the version of floating point code we |
| support. */ |
| if ((inst & 0xffbf0fff) == 0xec2d0200) /* sfmfd fn, <cnt>, [sp]! */ |
| continue; |
| |
| if ((inst & 0xffff8fff) == 0xed6d0103) /* stfe fn, [sp, #-12]! */ |
| continue; |
| |
| if ((inst & 0xfffff000) == 0xe24cb000) /* sub fp, ip, #nn */ |
| continue; |
| |
| if ((inst & 0xfffff000) == 0xe24dd000) /* sub sp, sp, #nn */ |
| continue; |
| |
| if ((inst & 0xffffc000) == 0xe54b0000 || /* strb r(0123),[r11,#-nn] */ |
| (inst & 0xffffc0f0) == 0xe14b00b0 || /* strh r(0123),[r11,#-nn] */ |
| (inst & 0xffffc000) == 0xe50b0000) /* str r(0123),[r11,#-nn] */ |
| continue; |
| |
| if ((inst & 0xffffc000) == 0xe5cd0000 || /* strb r(0123),[sp,#nn] */ |
| (inst & 0xffffc0f0) == 0xe1cd00b0 || /* strh r(0123),[sp,#nn] */ |
| (inst & 0xffffc000) == 0xe58d0000) /* str r(0123),[sp,#nn] */ |
| continue; |
| |
| /* Un-recognized instruction; stop scanning. */ |
| break; |
| } |
| |
| return skip_pc; /* End of prologue */ |
| } |
| |
| /* *INDENT-OFF* */ |
| /* Function: thumb_scan_prologue (helper function for arm_scan_prologue) |
| This function decodes a Thumb function prologue to determine: |
| 1) the size of the stack frame |
| 2) which registers are saved on it |
| 3) the offsets of saved regs |
| 4) the offset from the stack pointer to the frame pointer |
| This information is stored in the "extra" fields of the frame_info. |
| |
| A typical Thumb function prologue would create this stack frame |
| (offsets relative to FP) |
| old SP -> 24 stack parameters |
| 20 LR |
| 16 R7 |
| R7 -> 0 local variables (16 bytes) |
| SP -> -12 additional stack space (12 bytes) |
| The frame size would thus be 36 bytes, and the frame offset would be |
| 12 bytes. The frame register is R7. |
| |
| The comments for thumb_skip_prolog() describe the algorithm we use |
| to detect the end of the prolog. */ |
| /* *INDENT-ON* */ |
| |
| static void |
| thumb_scan_prologue (struct frame_info *fi) |
| { |
| CORE_ADDR prologue_start; |
| CORE_ADDR prologue_end; |
| CORE_ADDR current_pc; |
| /* Which register has been copied to register n? */ |
| int saved_reg[16]; |
| /* findmask: |
| bit 0 - push { rlist } |
| bit 1 - mov r7, sp OR add r7, sp, #imm (setting of r7) |
| bit 2 - sub sp, #simm OR add sp, #simm (adjusting of sp) |
| */ |
| int findmask = 0; |
| int i; |
| |
| /* Don't try to scan dummy frames. */ |
| if (USE_GENERIC_DUMMY_FRAMES |
| && fi != NULL |
| && PC_IN_CALL_DUMMY (fi->pc, 0, 0)) |
| return; |
| |
| if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) |
| { |
| struct symtab_and_line sal = find_pc_line (prologue_start, 0); |
| |
| if (sal.line == 0) /* no line info, use current PC */ |
| prologue_end = fi->pc; |
| else if (sal.end < prologue_end) /* next line begins after fn end */ |
| prologue_end = sal.end; /* (probably means no prologue) */ |
| } |
| else |
| /* We're in the boondocks: allow for |
| 16 pushes, an add, and "mv fp,sp". */ |
| prologue_end = prologue_start + 40; |
| |
| prologue_end = min (prologue_end, fi->pc); |
| |
| /* Initialize the saved register map. When register H is copied to |
| register L, we will put H in saved_reg[L]. */ |
| for (i = 0; i < 16; i++) |
| saved_reg[i] = i; |
| |
| /* Search the prologue looking for instructions that set up the |
| frame pointer, adjust the stack pointer, and save registers. |
| Do this until all basic prolog instructions are found. */ |
| |
| fi->extra_info->framesize = 0; |
| for (current_pc = prologue_start; |
| (current_pc < prologue_end) && ((findmask & 7) != 7); |
| current_pc += 2) |
| { |
| unsigned short insn; |
| int regno; |
| int offset; |
| |
| insn = read_memory_unsigned_integer (current_pc, 2); |
| |
| if ((insn & 0xfe00) == 0xb400) /* push { rlist } */ |
| { |
| int mask; |
| findmask |= 1; /* push found */ |
| /* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says |
| whether to save LR (R14). */ |
| mask = (insn & 0xff) | ((insn & 0x100) << 6); |
| |
| /* Calculate offsets of saved R0-R7 and LR. */ |
| for (regno = ARM_LR_REGNUM; regno >= 0; regno--) |
| if (mask & (1 << regno)) |
| { |
| fi->extra_info->framesize += 4; |
| fi->saved_regs[saved_reg[regno]] = |
| -(fi->extra_info->framesize); |
| /* Reset saved register map. */ |
| saved_reg[regno] = regno; |
| } |
| } |
| else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR |
| sub sp, #simm */ |
| { |
| if ((findmask & 1) == 0) /* before push? */ |
| continue; |
| else |
| findmask |= 4; /* add/sub sp found */ |
| |
| offset = (insn & 0x7f) << 2; /* get scaled offset */ |
| if (insn & 0x80) /* is it signed? (==subtracting) */ |
| { |
| fi->extra_info->frameoffset += offset; |
| offset = -offset; |
| } |
| fi->extra_info->framesize -= offset; |
| } |
| else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */ |
| { |
| findmask |= 2; /* setting of r7 found */ |
| fi->extra_info->framereg = THUMB_FP_REGNUM; |
| /* get scaled offset */ |
| fi->extra_info->frameoffset = (insn & 0xff) << 2; |
| } |
| else if (insn == 0x466f) /* mov r7, sp */ |
| { |
| findmask |= 2; /* setting of r7 found */ |
| fi->extra_info->framereg = THUMB_FP_REGNUM; |
| fi->extra_info->frameoffset = 0; |
| saved_reg[THUMB_FP_REGNUM] = ARM_SP_REGNUM; |
| } |
| else if ((insn & 0xffc0) == 0x4640) /* mov r0-r7, r8-r15 */ |
| { |
| int lo_reg = insn & 7; /* dest. register (r0-r7) */ |
| int hi_reg = ((insn >> 3) & 7) + 8; /* source register (r8-15) */ |
| saved_reg[lo_reg] = hi_reg; /* remember hi reg was saved */ |
| } |
| else |
| /* Something in the prolog that we don't care about or some |
| instruction from outside the prolog scheduled here for |
| optimization. */ |
| continue; |
| } |
| } |
| |
| /* Check if prologue for this frame's PC has already been scanned. If |
| it has, copy the relevant information about that prologue and |
| return non-zero. Otherwise do not copy anything and return zero. |
| |
| The information saved in the cache includes: |
| * the frame register number; |
| * the size of the stack frame; |
| * the offsets of saved regs (relative to the old SP); and |
| * the offset from the stack pointer to the frame pointer |
| |
| The cache contains only one entry, since this is adequate for the |
| typical sequence of prologue scan requests we get. When performing |
| a backtrace, GDB will usually ask to scan the same function twice |
| in a row (once to get the frame chain, and once to fill in the |
| extra frame information). */ |
| |
| static struct frame_info prologue_cache; |
| |
| static int |
| check_prologue_cache (struct frame_info *fi) |
| { |
| int i; |
| |
| if (fi->pc == prologue_cache.pc) |
| { |
| fi->extra_info->framereg = prologue_cache.extra_info->framereg; |
| fi->extra_info->framesize = prologue_cache.extra_info->framesize; |
| fi->extra_info->frameoffset = prologue_cache.extra_info->frameoffset; |
| for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++) |
| fi->saved_regs[i] = prologue_cache.saved_regs[i]; |
| return 1; |
| } |
| else |
| return 0; |
| } |
| |
| |
| /* Copy the prologue information from fi to the prologue cache. */ |
| |
| static void |
| save_prologue_cache (struct frame_info *fi) |
| { |
| int i; |
| |
| prologue_cache.pc = fi->pc; |
| prologue_cache.extra_info->framereg = fi->extra_info->framereg; |
| prologue_cache.extra_info->framesize = fi->extra_info->framesize; |
| prologue_cache.extra_info->frameoffset = fi->extra_info->frameoffset; |
| |
| for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++) |
| prologue_cache.saved_regs[i] = fi->saved_regs[i]; |
| } |
| |
| |
| /* This function decodes an ARM function prologue to determine: |
| 1) the size of the stack frame |
| 2) which registers are saved on it |
| 3) the offsets of saved regs |
| 4) the offset from the stack pointer to the frame pointer |
| This information is stored in the "extra" fields of the frame_info. |
| |
| There are two basic forms for the ARM prologue. The fixed argument |
| function call will look like: |
| |
| mov ip, sp |
| stmfd sp!, {fp, ip, lr, pc} |
| sub fp, ip, #4 |
| [sub sp, sp, #4] |
| |
| Which would create this stack frame (offsets relative to FP): |
| IP -> 4 (caller's stack) |
| FP -> 0 PC (points to address of stmfd instruction + 8 in callee) |
| -4 LR (return address in caller) |
| -8 IP (copy of caller's SP) |
| -12 FP (caller's FP) |
| SP -> -28 Local variables |
| |
| The frame size would thus be 32 bytes, and the frame offset would be |
| 28 bytes. The stmfd call can also save any of the vN registers it |
| plans to use, which increases the frame size accordingly. |
| |
| Note: The stored PC is 8 off of the STMFD instruction that stored it |
| because the ARM Store instructions always store PC + 8 when you read |
| the PC register. |
| |
| A variable argument function call will look like: |
| |
| mov ip, sp |
| stmfd sp!, {a1, a2, a3, a4} |
| stmfd sp!, {fp, ip, lr, pc} |
| sub fp, ip, #20 |
| |
| Which would create this stack frame (offsets relative to FP): |
| IP -> 20 (caller's stack) |
| 16 A4 |
| 12 A3 |
| 8 A2 |
| 4 A1 |
| FP -> 0 PC (points to address of stmfd instruction + 8 in callee) |
| -4 LR (return address in caller) |
| -8 IP (copy of caller's SP) |
| -12 FP (caller's FP) |
| SP -> -28 Local variables |
| |
| The frame size would thus be 48 bytes, and the frame offset would be |
| 28 bytes. |
| |
| There is another potential complication, which is that the optimizer |
| will try to separate the store of fp in the "stmfd" instruction from |
| the "sub fp, ip, #NN" instruction. Almost anything can be there, so |
| we just key on the stmfd, and then scan for the "sub fp, ip, #NN"... |
| |
| Also, note, the original version of the ARM toolchain claimed that there |
| should be an |
| |
| instruction at the end of the prologue. I have never seen GCC produce |
| this, and the ARM docs don't mention it. We still test for it below in |
| case it happens... |
| |
| */ |
| |
| static void |
| arm_scan_prologue (struct frame_info *fi) |
| { |
| int regno, sp_offset, fp_offset; |
| LONGEST return_value; |
| CORE_ADDR prologue_start, prologue_end, current_pc; |
| |
| /* Check if this function is already in the cache of frame information. */ |
| if (check_prologue_cache (fi)) |
| return; |
| |
| /* Assume there is no frame until proven otherwise. */ |
| fi->extra_info->framereg = ARM_SP_REGNUM; |
| fi->extra_info->framesize = 0; |
| fi->extra_info->frameoffset = 0; |
| |
| /* Check for Thumb prologue. */ |
| if (arm_pc_is_thumb (fi->pc)) |
| { |
| thumb_scan_prologue (fi); |
| save_prologue_cache (fi); |
| return; |
| } |
| |
| /* Find the function prologue. If we can't find the function in |
| the symbol table, peek in the stack frame to find the PC. */ |
| if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) |
| { |
| /* One way to find the end of the prologue (which works well |
| for unoptimized code) is to do the following: |
| |
| struct symtab_and_line sal = find_pc_line (prologue_start, 0); |
| |
| if (sal.line == 0) |
| prologue_end = fi->pc; |
| else if (sal.end < prologue_end) |
| prologue_end = sal.end; |
| |
| This mechanism is very accurate so long as the optimizer |
| doesn't move any instructions from the function body into the |
| prologue. If this happens, sal.end will be the last |
| instruction in the first hunk of prologue code just before |
| the first instruction that the scheduler has moved from |
| the body to the prologue. |
| |
| In order to make sure that we scan all of the prologue |
| instructions, we use a slightly less accurate mechanism which |
| may scan more than necessary. To help compensate for this |
| lack of accuracy, the prologue scanning loop below contains |
| several clauses which'll cause the loop to terminate early if |
| an implausible prologue instruction is encountered. |
| |
| The expression |
| |
| prologue_start + 64 |
| |
| is a suitable endpoint since it accounts for the largest |
| possible prologue plus up to five instructions inserted by |
| the scheduler. */ |
| |
| if (prologue_end > prologue_start + 64) |
| { |
| prologue_end = prologue_start + 64; /* See above. */ |
| } |
| } |
| else |
| { |
| /* Get address of the stmfd in the prologue of the callee; |
| the saved PC is the address of the stmfd + 8. */ |
| if (!safe_read_memory_integer (fi->frame, 4, &return_value)) |
| return; |
| else |
| { |
| prologue_start = ADDR_BITS_REMOVE (return_value) - 8; |
| prologue_end = prologue_start + 64; /* See above. */ |
| } |
| } |
| |
| /* Now search the prologue looking for instructions that set up the |
| frame pointer, adjust the stack pointer, and save registers. |
| |
| Be careful, however, and if it doesn't look like a prologue, |
| don't try to scan it. If, for instance, a frameless function |
| begins with stmfd sp!, then we will tell ourselves there is |
| a frame, which will confuse stack traceback, as well as "finish" |
| and other operations that rely on a knowledge of the stack |
| traceback. |
| |
| In the APCS, the prologue should start with "mov ip, sp" so |
| if we don't see this as the first insn, we will stop. |
| |
| [Note: This doesn't seem to be true any longer, so it's now an |
| optional part of the prologue. - Kevin Buettner, 2001-11-20] |
| |
| [Note further: The "mov ip,sp" only seems to be missing in |
| frameless functions at optimization level "-O2" or above, |
| in which case it is often (but not always) replaced by |
| "str lr, [sp, #-4]!". - Michael Snyder, 2002-04-23] */ |
| |
| sp_offset = fp_offset = 0; |
| |
| for (current_pc = prologue_start; |
| current_pc < prologue_end; |
| current_pc += 4) |
| { |
| unsigned int insn = read_memory_unsigned_integer (current_pc, 4); |
| |
| if (insn == 0xe1a0c00d) /* mov ip, sp */ |
| { |
| continue; |
| } |
| else if (insn == 0xe52de004) /* str lr, [sp, #-4]! */ |
| { |
| /* Function is frameless: extra_info defaults OK? */ |
| continue; |
| } |
| else if ((insn & 0xffff0000) == 0xe92d0000) |
| /* stmfd sp!, {..., fp, ip, lr, pc} |
| or |
| stmfd sp!, {a1, a2, a3, a4} */ |
| { |
| int mask = insn & 0xffff; |
| |
| /* Calculate offsets of saved registers. */ |
| for (regno = ARM_PC_REGNUM; regno >= 0; regno--) |
| if (mask & (1 << regno)) |
| { |
| sp_offset -= 4; |
| fi->saved_regs[regno] = sp_offset; |
| } |
| } |
| else if ((insn & 0xffffc000) == 0xe54b0000 || /* strb rx,[r11,#-n] */ |
| (insn & 0xffffc0f0) == 0xe14b00b0 || /* strh rx,[r11,#-n] */ |
| (insn & 0xffffc000) == 0xe50b0000) /* str rx,[r11,#-n] */ |
| { |
| /* No need to add this to saved_regs -- it's just an arg reg. */ |
| continue; |
| } |
| else if ((insn & 0xffffc000) == 0xe5cd0000 || /* strb rx,[sp,#n] */ |
| (insn & 0xffffc0f0) == 0xe1cd00b0 || /* strh rx,[sp,#n] */ |
| (insn & 0xffffc000) == 0xe58d0000) /* str rx,[sp,#n] */ |
| { |
| /* No need to add this to saved_regs -- it's just an arg reg. */ |
| continue; |
| } |
| else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */ |
| { |
| unsigned imm = insn & 0xff; /* immediate value */ |
| unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */ |
| imm = (imm >> rot) | (imm << (32 - rot)); |
| fp_offset = -imm; |
| fi->extra_info->framereg = ARM_FP_REGNUM; |
| } |
| else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */ |
| { |
| unsigned imm = insn & 0xff; /* immediate value */ |
| unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */ |
| imm = (imm >> rot) | (imm << (32 - rot)); |
| sp_offset -= imm; |
| } |
| else if ((insn & 0xffff7fff) == 0xed6d0103) /* stfe f?, [sp, -#c]! */ |
| { |
| sp_offset -= 12; |
| regno = ARM_F0_REGNUM + ((insn >> 12) & 0x07); |
| fi->saved_regs[regno] = sp_offset; |
| } |
| else if ((insn & 0xffbf0fff) == 0xec2d0200) /* sfmfd f0, 4, [sp!] */ |
| { |
| int n_saved_fp_regs; |
| unsigned int fp_start_reg, fp_bound_reg; |
| |
| if ((insn & 0x800) == 0x800) /* N0 is set */ |
| { |
| if ((insn & 0x40000) == 0x40000) /* N1 is set */ |
| n_saved_fp_regs = 3; |
| else |
| n_saved_fp_regs = 1; |
| } |
| else |
| { |
| if ((insn & 0x40000) == 0x40000) /* N1 is set */ |
| n_saved_fp_regs = 2; |
| else |
| n_saved_fp_regs = 4; |
| } |
| |
| fp_start_reg = ARM_F0_REGNUM + ((insn >> 12) & 0x7); |
| fp_bound_reg = fp_start_reg + n_saved_fp_regs; |
| for (; fp_start_reg < fp_bound_reg; fp_start_reg++) |
| { |
| sp_offset -= 12; |
| fi->saved_regs[fp_start_reg++] = sp_offset; |
| } |
| } |
| else if ((insn & 0xf0000000) != 0xe0000000) |
| break; /* Condition not true, exit early */ |
| else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */ |
| break; /* Don't scan past a block load */ |
| else |
| /* The optimizer might shove anything into the prologue, |
| so we just skip what we don't recognize. */ |
| continue; |
| } |
| |
| /* The frame size is just the negative of the offset (from the |
| original SP) of the last thing thing we pushed on the stack. |
| The frame offset is [new FP] - [new SP]. */ |
| fi->extra_info->framesize = -sp_offset; |
| if (fi->extra_info->framereg == ARM_FP_REGNUM) |
| fi->extra_info->frameoffset = fp_offset - sp_offset; |
| else |
| fi->extra_info->frameoffset = 0; |
| |
| save_prologue_cache (fi); |
| } |
| |
| /* Find REGNUM on the stack. Otherwise, it's in an active register. |
| One thing we might want to do here is to check REGNUM against the |
| clobber mask, and somehow flag it as invalid if it isn't saved on |
| the stack somewhere. This would provide a graceful failure mode |
| when trying to get the value of caller-saves registers for an inner |
| frame. */ |
| |
| static CORE_ADDR |
| arm_find_callers_reg (struct frame_info *fi, int regnum) |
| { |
| /* NOTE: cagney/2002-05-03: This function really shouldn't be |
| needed. Instead the (still being written) register unwind |
| function could be called directly. */ |
| for (; fi; fi = fi->next) |
| { |
| if (USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (fi->pc, 0, 0)) |
| { |
| return deprecated_read_register_dummy (fi->pc, fi->frame, regnum); |
| } |
| else if (fi->saved_regs[regnum] != 0) |
| { |
| /* NOTE: cagney/2002-05-03: This would normally need to |
| handle ARM_SP_REGNUM as a special case as, according to |
| the frame.h comments, saved_regs[SP_REGNUM] contains the |
| SP value not its address. It appears that the ARM isn't |
| doing this though. */ |
| return read_memory_integer (fi->saved_regs[regnum], |
| REGISTER_RAW_SIZE (regnum)); |
| } |
| } |
| return read_register (regnum); |
| } |
| /* Function: frame_chain Given a GDB frame, determine the address of |
| the calling function's frame. This will be used to create a new |
| GDB frame struct, and then INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC |
| will be called for the new frame. For ARM, we save the frame size |
| when we initialize the frame_info. */ |
| |
| static CORE_ADDR |
| arm_frame_chain (struct frame_info *fi) |
| { |
| CORE_ADDR caller_pc; |
| int framereg = fi->extra_info->framereg; |
| |
| if (USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (fi->pc, 0, 0)) |
| /* A generic call dummy's frame is the same as caller's. */ |
| return fi->frame; |
| |
| if (fi->pc < LOWEST_PC) |
| return 0; |
| |
| /* If the caller is the startup code, we're at the end of the chain. */ |
| caller_pc = FRAME_SAVED_PC (fi); |
| |
| /* If the caller is Thumb and the caller is ARM, or vice versa, |
| the frame register of the caller is different from ours. |
| So we must scan the prologue of the caller to determine its |
| frame register number. */ |
| /* XXX Fixme, we should try to do this without creating a temporary |
| caller_fi. */ |
| if (arm_pc_is_thumb (caller_pc) != arm_pc_is_thumb (fi->pc)) |
| { |
| struct frame_info caller_fi; |
| struct cleanup *old_chain; |
| |
| /* Create a temporary frame suitable for scanning the caller's |
| prologue. (Ugh.) */ |
| memset (&caller_fi, 0, sizeof (caller_fi)); |
| caller_fi.extra_info = (struct frame_extra_info *) |
| xcalloc (1, sizeof (struct frame_extra_info)); |
| old_chain = make_cleanup (xfree, caller_fi.extra_info); |
| caller_fi.saved_regs = (CORE_ADDR *) |
| xcalloc (1, SIZEOF_FRAME_SAVED_REGS); |
| make_cleanup (xfree, caller_fi.saved_regs); |
| |
| /* Now, scan the prologue and obtain the frame register. */ |
| caller_fi.pc = caller_pc; |
| arm_scan_prologue (&caller_fi); |
| framereg = caller_fi.extra_info->framereg; |
| |
| /* Deallocate the storage associated with the temporary frame |
| created above. */ |
| do_cleanups (old_chain); |
| } |
| |
| /* If the caller used a frame register, return its value. |
| Otherwise, return the caller's stack pointer. */ |
| if (framereg == ARM_FP_REGNUM || framereg == THUMB_FP_REGNUM) |
| return arm_find_callers_reg (fi, framereg); |
| else |
| return fi->frame + fi->extra_info->framesize; |
| } |
| |
| /* This function actually figures out the frame address for a given pc |
| and sp. This is tricky because we sometimes don't use an explicit |
| frame pointer, and the previous stack pointer isn't necessarily |
| recorded on the stack. The only reliable way to get this info is |
| to examine the prologue. FROMLEAF is a little confusing, it means |
| this is the next frame up the chain AFTER a frameless function. If |
| this is true, then the frame value for this frame is still in the |
| fp register. */ |
| |
| static void |
| arm_init_extra_frame_info (int fromleaf, struct frame_info *fi) |
| { |
| int reg; |
| CORE_ADDR sp; |
| |
| if (fi->saved_regs == NULL) |
| frame_saved_regs_zalloc (fi); |
| |
| fi->extra_info = (struct frame_extra_info *) |
| frame_obstack_alloc (sizeof (struct frame_extra_info)); |
| |
| fi->extra_info->framesize = 0; |
| fi->extra_info->frameoffset = 0; |
| fi->extra_info->framereg = 0; |
| |
| if (fi->next) |
| fi->pc = FRAME_SAVED_PC (fi->next); |
| |
| memset (fi->saved_regs, '\000', sizeof fi->saved_regs); |
| |
| /* Compute stack pointer for this frame. We use this value for both |
| the sigtramp and call dummy cases. */ |
| if (!fi->next) |
| sp = read_sp(); |
| else if (USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (fi->next->pc, 0, 0)) |
| /* For generic dummy frames, pull the value direct from the frame. |
| Having an unwind function to do this would be nice. */ |
| sp = deprecated_read_register_dummy (fi->next->pc, fi->next->frame, |
| ARM_SP_REGNUM); |
| else |
| sp = (fi->next->frame - fi->next->extra_info->frameoffset |
| + fi->next->extra_info->framesize); |
| |
| /* Determine whether or not we're in a sigtramp frame. |
| Unfortunately, it isn't sufficient to test |
| fi->signal_handler_caller because this value is sometimes set |
| after invoking INIT_EXTRA_FRAME_INFO. So we test *both* |
| fi->signal_handler_caller and PC_IN_SIGTRAMP to determine if we |
| need to use the sigcontext addresses for the saved registers. |
| |
| Note: If an ARM PC_IN_SIGTRAMP method ever needs to compare |
| against the name of the function, the code below will have to be |
| changed to first fetch the name of the function and then pass |
| this name to PC_IN_SIGTRAMP. */ |
| |
| if (SIGCONTEXT_REGISTER_ADDRESS_P () |
| && (fi->signal_handler_caller || PC_IN_SIGTRAMP (fi->pc, (char *)0))) |
| { |
| for (reg = 0; reg < NUM_REGS; reg++) |
| fi->saved_regs[reg] = SIGCONTEXT_REGISTER_ADDRESS (sp, fi->pc, reg); |
| |
| /* FIXME: What about thumb mode? */ |
| fi->extra_info->framereg = ARM_SP_REGNUM; |
| fi->frame = |
| read_memory_integer (fi->saved_regs[fi->extra_info->framereg], |
| REGISTER_RAW_SIZE (fi->extra_info->framereg)); |
| fi->extra_info->framesize = 0; |
| fi->extra_info->frameoffset = 0; |
| |
| } |
| else if (!USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (fi->pc, sp, fi->frame)) |
| { |
| CORE_ADDR rp; |
| CORE_ADDR callers_sp; |
| |
| /* Set rp point at the high end of the saved registers. */ |
| rp = fi->frame - REGISTER_SIZE; |
| |
| /* Fill in addresses of saved registers. */ |
| fi->saved_regs[ARM_PS_REGNUM] = rp; |
| rp -= REGISTER_RAW_SIZE (ARM_PS_REGNUM); |
| for (reg = ARM_PC_REGNUM; reg >= 0; reg--) |
| { |
| fi->saved_regs[reg] = rp; |
| rp -= REGISTER_RAW_SIZE (reg); |
| } |
| |
| callers_sp = read_memory_integer (fi->saved_regs[ARM_SP_REGNUM], |
| REGISTER_RAW_SIZE (ARM_SP_REGNUM)); |
| if (arm_pc_is_thumb (fi->pc)) |
| fi->extra_info->framereg = THUMB_FP_REGNUM; |
| else |
| fi->extra_info->framereg = ARM_FP_REGNUM; |
| fi->extra_info->framesize = callers_sp - sp; |
| fi->extra_info->frameoffset = fi->frame - sp; |
| } |
| else |
| { |
| arm_scan_prologue (fi); |
| |
| if (!fi->next) |
| /* This is the innermost frame? */ |
| fi->frame = read_register (fi->extra_info->framereg); |
| else if (USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (fi->next->pc, 0, 0)) |
| /* Next inner most frame is a dummy, just grab its frame. |
| Dummy frames always have the same FP as their caller. */ |
| fi->frame = fi->next->frame; |
| else if (fi->extra_info->framereg == ARM_FP_REGNUM |
| || fi->extra_info->framereg == THUMB_FP_REGNUM) |
| { |
| /* not the innermost frame */ |
| /* If we have an FP, the callee saved it. */ |
| if (fi->next->saved_regs[fi->extra_info->framereg] != 0) |
| fi->frame = |
| read_memory_integer (fi->next |
| ->saved_regs[fi->extra_info->framereg], 4); |
| else if (fromleaf) |
| /* If we were called by a frameless fn. then our frame is |
| still in the frame pointer register on the board... */ |
| fi->frame = read_fp (); |
| } |
| |
| /* Calculate actual addresses of saved registers using offsets |
| determined by arm_scan_prologue. */ |
| for (reg = 0; reg < NUM_REGS; reg++) |
| if (fi->saved_regs[reg] != 0) |
| fi->saved_regs[reg] += (fi->frame + fi->extra_info->framesize |
| - fi->extra_info->frameoffset); |
| } |
| } |
| |
| |
| /* Find the caller of this frame. We do this by seeing if ARM_LR_REGNUM |
| is saved in the stack anywhere, otherwise we get it from the |
| registers. |
| |
| The old definition of this function was a macro: |
| #define FRAME_SAVED_PC(FRAME) \ |
| ADDR_BITS_REMOVE (read_memory_integer ((FRAME)->frame - 4, 4)) */ |
| |
| static CORE_ADDR |
| arm_frame_saved_pc (struct frame_info *fi) |
| { |
| /* If a dummy frame, pull the PC out of the frame's register buffer. */ |
| if (USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (fi->pc, 0, 0)) |
| return deprecated_read_register_dummy (fi->pc, fi->frame, ARM_PC_REGNUM); |
| |
| if (PC_IN_CALL_DUMMY (fi->pc, fi->frame - fi->extra_info->frameoffset, |
| fi->frame)) |
| { |
| return read_memory_integer (fi->saved_regs[ARM_PC_REGNUM], |
| REGISTER_RAW_SIZE (ARM_PC_REGNUM)); |
| } |
| else |
| { |
| CORE_ADDR pc = arm_find_callers_reg (fi, ARM_LR_REGNUM); |
| return IS_THUMB_ADDR (pc) ? UNMAKE_THUMB_ADDR (pc) : pc; |
| } |
| } |
| |
| /* Return the frame address. On ARM, it is R11; on Thumb it is R7. |
| Examine the Program Status Register to decide which state we're in. */ |
| |
| static CORE_ADDR |
| arm_read_fp (void) |
| { |
| if (read_register (ARM_PS_REGNUM) & 0x20) /* Bit 5 is Thumb state bit */ |
| return read_register (THUMB_FP_REGNUM); /* R7 if Thumb */ |
| else |
| return read_register (ARM_FP_REGNUM); /* R11 if ARM */ |
| } |
| |
| /* Store into a struct frame_saved_regs the addresses of the saved |
| registers of frame described by FRAME_INFO. This includes special |
| registers such as PC and FP saved in special ways in the stack |
| frame. SP is even more special: the address we return for it IS |
| the sp for the next frame. */ |
| |
| static void |
| arm_frame_init_saved_regs (struct frame_info *fip) |
| { |
| |
| if (fip->saved_regs) |
| return; |
| |
| arm_init_extra_frame_info (0, fip); |
| } |
| |
| /* Set the return address for a generic dummy frame. ARM uses the |
| entry point. */ |
| |
| static CORE_ADDR |
| arm_push_return_address (CORE_ADDR pc, CORE_ADDR sp) |
| { |
| write_register (ARM_LR_REGNUM, CALL_DUMMY_ADDRESS ()); |
| return sp; |
| } |
| |
| /* Push an empty stack frame, to record the current PC, etc. */ |
| |
| static void |
| arm_push_dummy_frame (void) |
| { |
| CORE_ADDR old_sp = read_register (ARM_SP_REGNUM); |
| CORE_ADDR sp = old_sp; |
| CORE_ADDR fp, prologue_start; |
| int regnum; |
| |
| /* Push the two dummy prologue instructions in reverse order, |
| so that they'll be in the correct low-to-high order in memory. */ |
| /* sub fp, ip, #4 */ |
| sp = push_word (sp, 0xe24cb004); |
| /* stmdb sp!, {r0-r10, fp, ip, lr, pc} */ |
| prologue_start = sp = push_word (sp, 0xe92ddfff); |
| |
| /* Push a pointer to the dummy prologue + 12, because when stm |
| instruction stores the PC, it stores the address of the stm |
| instruction itself plus 12. */ |
| fp = sp = push_word (sp, prologue_start + 12); |
| |
| /* Push the processor status. */ |
| sp = push_word (sp, read_register (ARM_PS_REGNUM)); |
| |
| /* Push all 16 registers starting with r15. */ |
| for (regnum = ARM_PC_REGNUM; regnum >= 0; regnum--) |
| sp = push_word (sp, read_register (regnum)); |
| |
| /* Update fp (for both Thumb and ARM) and sp. */ |
| write_register (ARM_FP_REGNUM, fp); |
| write_register (THUMB_FP_REGNUM, fp); |
| write_register (ARM_SP_REGNUM, sp); |
| } |
| |
| /* CALL_DUMMY_WORDS: |
| This sequence of words is the instructions |
| |
| mov lr,pc |
| mov pc,r4 |
| illegal |
| |
| Note this is 12 bytes. */ |
| |
| static LONGEST arm_call_dummy_words[] = |
| { |
| 0xe1a0e00f, 0xe1a0f004, 0xe7ffdefe |
| }; |
| |
| /* Adjust the call_dummy_breakpoint_offset for the bp_call_dummy |
| breakpoint to the proper address in the call dummy, so that |
| `finish' after a stop in a call dummy works. |
| |
| FIXME rearnsha 2002-02018: Tweeking current_gdbarch is not an |
| optimal solution, but the call to arm_fix_call_dummy is immediately |
| followed by a call to run_stack_dummy, which is the only function |
| where call_dummy_breakpoint_offset is actually used. */ |
| |
| |
| static void |
| arm_set_call_dummy_breakpoint_offset (void) |
| { |
| if (caller_is_thumb) |
| set_gdbarch_call_dummy_breakpoint_offset (current_gdbarch, 4); |
| else |
| set_gdbarch_call_dummy_breakpoint_offset (current_gdbarch, 8); |
| } |
| |
| /* Fix up the call dummy, based on whether the processor is currently |
| in Thumb or ARM mode, and whether the target function is Thumb or |
| ARM. There are three different situations requiring three |
| different dummies: |
| |
| * ARM calling ARM: uses the call dummy in tm-arm.h, which has already |
| been copied into the dummy parameter to this function. |
| * ARM calling Thumb: uses the call dummy in tm-arm.h, but with the |
| "mov pc,r4" instruction patched to be a "bx r4" instead. |
| * Thumb calling anything: uses the Thumb dummy defined below, which |
| works for calling both ARM and Thumb functions. |
| |
| All three call dummies expect to receive the target function |
| address in R4, with the low bit set if it's a Thumb function. */ |
| |
| static void |
| arm_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs, |
| struct value **args, struct type *type, int gcc_p) |
| { |
| static short thumb_dummy[4] = |
| { |
| 0xf000, 0xf801, /* bl label */ |
| 0xdf18, /* swi 24 */ |
| 0x4720, /* label: bx r4 */ |
| }; |
| static unsigned long arm_bx_r4 = 0xe12fff14; /* bx r4 instruction */ |
| |
| /* Set flag indicating whether the current PC is in a Thumb function. */ |
| caller_is_thumb = arm_pc_is_thumb (read_pc ()); |
| arm_set_call_dummy_breakpoint_offset (); |
| |
| /* If the target function is Thumb, set the low bit of the function |
| address. And if the CPU is currently in ARM mode, patch the |
| second instruction of call dummy to use a BX instruction to |
| switch to Thumb mode. */ |
| target_is_thumb = arm_pc_is_thumb (fun); |
| if (target_is_thumb) |
| { |
| fun |= 1; |
| if (!caller_is_thumb) |
| store_unsigned_integer (dummy + 4, sizeof (arm_bx_r4), arm_bx_r4); |
| } |
| |
| /* If the CPU is currently in Thumb mode, use the Thumb call dummy |
| instead of the ARM one that's already been copied. This will |
| work for both Thumb and ARM target functions. */ |
| if (caller_is_thumb) |
| { |
| int i; |
| char *p = dummy; |
| int len = sizeof (thumb_dummy) / sizeof (thumb_dummy[0]); |
| |
| for (i = 0; i < len; i++) |
| { |
| store_unsigned_integer (p, sizeof (thumb_dummy[0]), thumb_dummy[i]); |
| p += sizeof (thumb_dummy[0]); |
| } |
| } |
| |
| /* Put the target address in r4; the call dummy will copy this to |
| the PC. */ |
| write_register (4, fun); |
| } |
| |
| /* Note: ScottB |
| |
| This function does not support passing parameters using the FPA |
| variant of the APCS. It passes any floating point arguments in the |
| general registers and/or on the stack. */ |
| |
| static CORE_ADDR |
| arm_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
| int struct_return, CORE_ADDR struct_addr) |
| { |
| CORE_ADDR fp; |
| int argnum; |
| int argreg; |
| int nstack; |
| int simd_argreg; |
| int second_pass; |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| |
| /* Walk through the list of args and determine how large a temporary |
| stack is required. Need to take care here as structs may be |
| passed on the stack, and we have to to push them. On the second |
| pass, do the store. */ |
| nstack = 0; |
| fp = sp; |
| for (second_pass = 0; second_pass < 2; second_pass++) |
| { |
| /* Compute the FP using the information computed during the |
| first pass. */ |
| if (second_pass) |
| fp = sp - nstack; |
| |
| simd_argreg = 0; |
| argreg = ARM_A1_REGNUM; |
| nstack = 0; |
| |
| /* The struct_return pointer occupies the first parameter |
| passing register. */ |
| if (struct_return) |
| { |
| if (second_pass) |
| { |
| if (arm_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "struct return in %s = 0x%s\n", |
| REGISTER_NAME (argreg), |
| paddr (struct_addr)); |
| write_register (argreg, struct_addr); |
| } |
| argreg++; |
| } |
| |
| for (argnum = 0; argnum < nargs; argnum++) |
| { |
| int len; |
| struct type *arg_type; |
| struct type *target_type; |
| enum type_code typecode; |
| char *val; |
| |
| arg_type = check_typedef (VALUE_TYPE (args[argnum])); |
| len = TYPE_LENGTH (arg_type); |
| target_type = TYPE_TARGET_TYPE (arg_type); |
| typecode = TYPE_CODE (arg_type); |
| val = VALUE_CONTENTS (args[argnum]); |
| |
| /* If the argument is a pointer to a function, and it is a |
| Thumb function, create a LOCAL copy of the value and set |
| the THUMB bit in it. */ |
| if (second_pass |
| && TYPE_CODE_PTR == typecode |
| && target_type != NULL |
| && TYPE_CODE_FUNC == TYPE_CODE (target_type)) |
| { |
| CORE_ADDR regval = extract_address (val, len); |
| if (arm_pc_is_thumb (regval)) |
| { |
| val = alloca (len); |
| store_address (val, len, MAKE_THUMB_ADDR (regval)); |
| } |
| } |
| |
| /* Copy the argument to general registers or the stack in |
| register-sized pieces. Large arguments are split between |
| registers and stack. */ |
| while (len > 0) |
| { |
| int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE; |
| |
| if (argreg <= ARM_LAST_ARG_REGNUM) |
| { |
| /* The argument is being passed in a general purpose |
| register. */ |
| if (second_pass) |
| { |
| CORE_ADDR regval = extract_address (val, |
| partial_len); |
| if (arm_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "arg %d in %s = 0x%s\n", |
| argnum, |
| REGISTER_NAME (argreg), |
| phex (regval, REGISTER_SIZE)); |
| write_register (argreg, regval); |
| } |
| argreg++; |
| } |
| else |
| { |
| if (second_pass) |
| { |
| /* Push the arguments onto the stack. */ |
| if (arm_debug) |
| fprintf_unfiltered (gdb_stdlog, |
| "arg %d @ 0x%s + %d\n", |
| argnum, paddr (fp), nstack); |
| write_memory (fp + nstack, val, REGISTER_SIZE); |
| } |
| nstack += REGISTER_SIZE; |
| } |
| |
| len -= partial_len; |
| val += partial_len; |
| } |
| |
| } |
| } |
| |
| /* Return the botom of the argument list (pointed to by fp). */ |
| return fp; |
| } |
| |
| /* Pop the current frame. So long as the frame info has been |
| initialized properly (see arm_init_extra_frame_info), this code |
| works for dummy frames as well as regular frames. I.e, there's no |
| need to have a special case for dummy frames. */ |
| static void |
| arm_pop_frame (void) |
| { |
| int regnum; |
| struct frame_info *frame = get_current_frame (); |
| CORE_ADDR old_SP = (frame->frame - frame->extra_info->frameoffset |
| + frame->extra_info->framesize); |
| |
| if (USE_GENERIC_DUMMY_FRAMES |
| && PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) |
| { |
| generic_pop_dummy_frame (); |
| flush_cached_frames (); |
| return; |
| } |
| |
| for (regnum = 0; regnum < NUM_REGS; regnum++) |
| if (frame->saved_regs[regnum] != 0) |
| write_register (regnum, |
| read_memory_integer (frame->saved_regs[regnum], |
| REGISTER_RAW_SIZE (regnum))); |
| |
| write_register (ARM_PC_REGNUM, FRAME_SAVED_PC (frame)); |
| write_register (ARM_SP_REGNUM, old_SP); |
| |
| flush_cached_frames (); |
| } |
| |
| static void |
| print_fpu_flags (int flags) |
| { |
| if (flags & (1 << 0)) |
| fputs ("IVO ", stdout); |
| if (flags & (1 << 1)) |
| fputs ("DVZ ", stdout); |
| if (flags & (1 << 2)) |
| fputs ("OFL ", stdout); |
| if (flags & (1 << 3)) |
| fputs ("UFL ", stdout); |
| if (flags & (1 << 4)) |
| fputs ("INX ", stdout); |
| putchar ('\n'); |
| } |
| |
| /* Print interesting information about the floating point processor |
| (if present) or emulator. */ |
| static void |
| arm_print_float_info (struct gdbarch *gdbarch, struct ui_file *file, |
| struct frame_info *frame, const char *args) |
| { |
| register unsigned long status = read_register (ARM_FPS_REGNUM); |
| int type; |
| |
| type = (status >> 24) & 127; |
| printf ("%s FPU type %d\n", |
| (status & (1 << 31)) ? "Hardware" : "Software", |
| type); |
| fputs ("mask: ", stdout); |
| print_fpu_flags (status >> 16); |
| fputs ("flags: ", stdout); |
| print_fpu_flags (status); |
| } |
| |
| /* Return the GDB type object for the "standard" data type of data in |
| register N. */ |
| |
| static struct type * |
| arm_register_type (int regnum) |
| { |
| if (regnum >= ARM_F0_REGNUM && regnum < ARM_F0_REGNUM + NUM_FREGS) |
| { |
| if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| return builtin_type_arm_ext_big; |
| else |
| return builtin_type_arm_ext_littlebyte_bigword; |
| } |
| else |
| return builtin_type_int32; |
| } |
| |
| /* Index within `registers' of the first byte of the space for |
| register N. */ |
| |
| static int |
| arm_register_byte (int regnum) |
| { |
| if (regnum < ARM_F0_REGNUM) |
| return regnum * INT_REGISTER_RAW_SIZE; |
| else if (regnum < ARM_PS_REGNUM) |
| return (NUM_GREGS * INT_REGISTER_RAW_SIZE |
| + (regnum - ARM_F0_REGNUM) * FP_REGISTER_RAW_SIZE); |
| else |
| return (NUM_GREGS * INT_REGISTER_RAW_SIZE |
| + NUM_FREGS * FP_REGISTER_RAW_SIZE |
| + (regnum - ARM_FPS_REGNUM) * STATUS_REGISTER_SIZE); |
| } |
| |
| /* Number of bytes of storage in the actual machine representation for |
| register N. All registers are 4 bytes, except fp0 - fp7, which are |
| 12 bytes in length. */ |
| |
| static int |
| arm_register_raw_size (int regnum) |
| { |
| if (regnum < ARM_F0_REGNUM) |
| return INT_REGISTER_RAW_SIZE; |
| else if (regnum < ARM_FPS_REGNUM) |
| return FP_REGISTER_RAW_SIZE; |
| else |
| return STATUS_REGISTER_SIZE; |
| } |
| |
| /* Number of bytes of storage in a program's representation |
| for register N. */ |
| static int |
| arm_register_virtual_size (int regnum) |
| { |
| if (regnum < ARM_F0_REGNUM) |
| return INT_REGISTER_VIRTUAL_SIZE; |
| else if (regnum < ARM_FPS_REGNUM) |
| return FP_REGISTER_VIRTUAL_SIZE; |
| else |
| return STATUS_REGISTER_SIZE; |
| } |
| |
| /* Map GDB internal REGNUM onto the Arm simulator register numbers. */ |
| static int |
| arm_register_sim_regno (int regnum) |
| { |
| int reg = regnum; |
| gdb_assert (reg >= 0 && reg < NUM_REGS); |
| |
| if (reg < NUM_GREGS) |
| return SIM_ARM_R0_REGNUM + reg; |
| reg -= NUM_GREGS; |
| |
| if (reg < NUM_FREGS) |
| return SIM_ARM_FP0_REGNUM + reg; |
| reg -= NUM_FREGS; |
| |
| if (reg < NUM_SREGS) |
| return SIM_ARM_FPS_REGNUM + reg; |
| reg -= NUM_SREGS; |
| |
| internal_error (__FILE__, __LINE__, "Bad REGNUM %d", regnum); |
| } |
| |
| /* NOTE: cagney/2001-08-20: Both convert_from_extended() and |
| convert_to_extended() use floatformat_arm_ext_littlebyte_bigword. |
| It is thought that this is is the floating-point register format on |
| little-endian systems. */ |
| |
| static void |
| convert_from_extended (void *ptr, void *dbl) |
| { |
| DOUBLEST d; |
| if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| floatformat_to_doublest (&floatformat_arm_ext_big, ptr, &d); |
| else |
| floatformat_to_doublest (&floatformat_arm_ext_littlebyte_bigword, |
| ptr, &d); |
| floatformat_from_doublest (TARGET_DOUBLE_FORMAT, &d, dbl); |
| } |
| |
| static void |
| convert_to_extended (void *dbl, void *ptr) |
| { |
| DOUBLEST d; |
| floatformat_to_doublest (TARGET_DOUBLE_FORMAT, ptr, &d); |
| if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| floatformat_from_doublest (&floatformat_arm_ext_big, &d, dbl); |
| else |
| floatformat_from_doublest (&floatformat_arm_ext_littlebyte_bigword, |
| &d, dbl); |
| } |
| |
| static int |
| condition_true (unsigned long cond, unsigned long status_reg) |
| { |
| if (cond == INST_AL || cond == INST_NV) |
| return 1; |
| |
| switch (cond) |
| { |
| case INST_EQ: |
| return ((status_reg & FLAG_Z) != 0); |
| case INST_NE: |
| return ((status_reg & FLAG_Z) == 0); |
| case INST_CS: |
| return ((status_reg & FLAG_C) != 0); |
| case INST_CC: |
| return ((status_reg & FLAG_C) == 0); |
| case INST_MI: |
| return ((status_reg & FLAG_N) != 0); |
| case INST_PL: |
| return ((status_reg & FLAG_N) == 0); |
| case INST_VS: |
| return ((status_reg & FLAG_V) != 0); |
| case INST_VC: |
| return ((status_reg & FLAG_V) == 0); |
| case INST_HI: |
| return ((status_reg & (FLAG_C | FLAG_Z)) == FLAG_C); |
| case INST_LS: |
| return ((status_reg & (FLAG_C | FLAG_Z)) != FLAG_C); |
| case INST_GE: |
| return (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0)); |
| case INST_LT: |
| return (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0)); |
| case INST_GT: |
| return (((status_reg & FLAG_Z) == 0) && |
| (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0))); |
| case INST_LE: |
| return (((status_reg & FLAG_Z) != 0) || |
| (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0))); |
| } |
| return 1; |
| } |
| |
| /* Support routines for single stepping. Calculate the next PC value. */ |
| #define submask(x) ((1L << ((x) + 1)) - 1) |
| #define bit(obj,st) (((obj) >> (st)) & 1) |
| #define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st))) |
| #define sbits(obj,st,fn) \ |
| ((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st)))) |
| #define BranchDest(addr,instr) \ |
| ((CORE_ADDR) (((long) (addr)) + 8 + (sbits (instr, 0, 23) << 2))) |
| #define ARM_PC_32 1 |
| |
| static unsigned long |
| shifted_reg_val (unsigned long inst, int carry, unsigned long pc_val, |
| unsigned long status_reg) |
| { |
| unsigned long res, shift; |
| int rm = bits (inst, 0, 3); |
| unsigned long shifttype = bits (inst, 5, 6); |
| |
| if (bit (inst, 4)) |
| { |
| int rs = bits (inst, 8, 11); |
| shift = (rs == 15 ? pc_val + 8 : read_register (rs)) & 0xFF; |
| } |
| else |
| shift = bits (inst, 7, 11); |
| |
| res = (rm == 15 |
| ? ((pc_val | (ARM_PC_32 ? 0 : status_reg)) |
| + (bit (inst, 4) ? 12 : 8)) |
| : read_register (rm)); |
| |
| switch (shifttype) |
| { |
| case 0: /* LSL */ |
| res = shift >= 32 ? 0 : res << shift; |
| break; |
| |
| case 1: /* LSR */ |
| res = shift >= 32 ? 0 : res >> shift; |
| break; |
| |
| case 2: /* ASR */ |
| if (shift >= 32) |
| shift = 31; |
| res = ((res & 0x80000000L) |
| ? ~((~res) >> shift) : res >> shift); |
| break; |
| |
| case 3: /* ROR/RRX */ |
| shift &= 31; |
| if (shift == 0) |
| res = (res >> 1) | (carry ? 0x80000000L : 0); |
| else |
| res = (res >> shift) | (res << (32 - shift)); |
| break; |
| } |
| |
| return res & 0xffffffff; |
| } |
| |
| /* Return number of 1-bits in VAL. */ |
| |
| static int |
| bitcount (unsigned long val) |
| { |
| int nbits; |
| for (nbits = 0; val != 0; nbits++) |
| val &= val - 1; /* delete rightmost 1-bit in val */ |
| return nbits; |
| } |
| |
| CORE_ADDR |
| thumb_get_next_pc (CORE_ADDR pc) |
| { |
| unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */ |
| unsigned short inst1 = read_memory_integer (pc, 2); |
| CORE_ADDR nextpc = pc + 2; /* default is next instruction */ |
| unsigned long offset; |
| |
| if ((inst1 & 0xff00) == 0xbd00) /* pop {rlist, pc} */ |
| { |
| CORE_ADDR sp; |
| |
| /* Fetch the saved PC from the stack. It's stored above |
| all of the other registers. */ |
| offset = bitcount (bits (inst1, 0, 7)) * REGISTER_SIZE; |
| sp = read_register (ARM_SP_REGNUM); |
| nextpc = (CORE_ADDR) read_memory_integer (sp + offset, 4); |
| nextpc = ADDR_BITS_REMOVE (nextpc); |
| if (nextpc == pc) |
| error ("Infinite loop detected"); |
| } |
| else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */ |
| { |
| unsigned long status = read_register (ARM_PS_REGNUM); |
| unsigned long cond = bits (inst1, 8, 11); |
| if (cond != 0x0f && condition_true (cond, status)) /* 0x0f = SWI */ |
| nextpc = pc_val + (sbits (inst1, 0, 7) << 1); |
| } |
| else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */ |
| { |
| nextpc = pc_val + (sbits (inst1, 0, 10) << 1); |
| } |
| else if ((inst1 & 0xf800) == 0xf000) /* long branch with link */ |
| { |
| unsigned short inst2 = read_memory_integer (pc + 2, 2); |
| offset = (sbits (inst1, 0, 10) << 12) + (bits (inst2, 0, 10) << 1); |
| nextpc = pc_val + offset; |
| } |
| |
| return nextpc; |
| } |
| |
| CORE_ADDR |
| arm_get_next_pc (CORE_ADDR pc) |
| { |
| unsigned long pc_val; |
| unsigned long this_instr; |
| unsigned long status; |
| CORE_ADDR nextpc; |
| |
| if (arm_pc_is_thumb (pc)) |
| return thumb_get_next_pc (pc); |
| |
| pc_val = (unsigned long) pc; |
| this_instr = read_memory_integer (pc, 4); |
| status = read_register (ARM_PS_REGNUM); |
| nextpc = (CORE_ADDR) (pc_val + 4); /* Default case */ |
| |
| if (condition_true (bits (this_instr, 28, 31), status)) |
| { |
| switch (bits (this_instr, 24, 27)) |
| { |
| case 0x0: |
| case 0x1: /* data processing */ |
| case 0x2: |
| case 0x3: |
| { |
| unsigned long operand1, operand2, result = 0; |
| unsigned long rn; |
| int c; |
| |
| if (bits (this_instr, 12, 15) != 15) |
| break; |
| |
| if (bits (this_instr, 22, 25) == 0 |
| && bits (this_instr, 4, 7) == 9) /* multiply */ |
| error ("Illegal update to pc in instruction"); |
| |
| /* Multiply into PC */ |
| c = (status & FLAG_C) ? 1 : 0; |
| rn = bits (this_instr, 16, 19); |
| operand1 = (rn == 15) ? pc_val + 8 : read_register (rn); |
| |
| if (bit (this_instr, 25)) |
| { |
| unsigned long immval = bits (this_instr, 0, 7); |
| unsigned long rotate = 2 * bits (this_instr, 8, 11); |
| operand2 = ((immval >> rotate) | (immval << (32 - rotate))) |
| & 0xffffffff; |
| } |
| else /* operand 2 is a shifted register */ |
| operand2 = shifted_reg_val (this_instr, c, pc_val, status); |
| |
| switch (bits (this_instr, 21, 24)) |
| { |
| case 0x0: /*and */ |
| result = operand1 & operand2; |
| break; |
| |
| case 0x1: /*eor */ |
| result = operand1 ^ operand2; |
| break; |
| |
| case 0x2: /*sub */ |
| result = operand1 - operand2; |
| break; |
| |
| case 0x3: /*rsb */ |
| result = operand2 - operand1; |
| break; |
| |
| case 0x4: /*add */ |
| result = operand1 + operand2; |
| break; |
| |
| case 0x5: /*adc */ |
| result = operand1 + operand2 + c; |
| break; |
| |
| case 0x6: /*sbc */ |
| result = operand1 - operand2 + c; |
| break; |
| |
| case 0x7: /*rsc */ |
| result = operand2 - operand1 + c; |
| break; |
| |
| case 0x8: |
| case 0x9: |
| case 0xa: |
| case 0xb: /* tst, teq, cmp, cmn */ |
| result = (unsigned long) nextpc; |
| break; |
| |
| case 0xc: /*orr */ |
| result = operand1 | operand2; |
| break; |
| |
| case 0xd: /*mov */ |
| /* Always step into a function. */ |
| result = operand2; |
| break; |
| |
| case 0xe: /*bic */ |
| result = operand1 & ~operand2; |
| break; |
| |
| case 0xf: /*mvn */ |
| result = ~operand2; |
| break; |
| } |
| nextpc = (CORE_ADDR) ADDR_BITS_REMOVE (result); |
| |
| if (nextpc == pc) |
| error ("Infinite loop detected"); |
| break; |
| } |
| |
| case 0x4: |
| case 0x5: /* data transfer */ |
| case 0x6: |
| case 0x7: |
| if (bit (this_instr, 20)) |
| { |
| /* load */ |
| if (bits (this_instr, 12, 15) == 15) |
| { |
| /* rd == pc */ |
| unsigned long rn; |
| unsigned long base; |
| |
| if (bit (this_instr, 22)) |
| error ("Illegal update to pc in instruction"); |
| |
| /* byte write to PC */ |
| rn = bits (this_instr, 16, 19); |
| base = (rn == 15) ? pc_val + 8 : read_register (rn); |
| if (bit (this_instr, 24)) |
| { |
| /* pre-indexed */ |
| int c = (status & FLAG_C) ? 1 : 0; |
| unsigned long offset = |
| (bit (this_instr, 25) |
| ? shifted_reg_val (this_instr, c, pc_val, status) |
| : bits (this_instr, 0, 11)); |
| |
| if (bit (this_instr, 23)) |
| base += offset; |
| else |
| base -= offset; |
| } |
| nextpc = (CORE_ADDR) read_memory_integer ((CORE_ADDR) base, |
| 4); |
| |
| nextpc = ADDR_BITS_REMOVE (nextpc); |
| |
| if (nextpc == pc) |
| error ("Infinite loop detected"); |
| } |
| } |
| break; |
| |
| case 0x8: |
| case 0x9: /* block transfer */ |
| if (bit (this_instr, 20)) |
| { |
| /* LDM */ |
| if (bit (this_instr, 15)) |
| { |
| /* loading pc */ |
| int offset = 0; |
| |
| if (bit (this_instr, 23)) |
| { |
| /* up */ |
| unsigned long reglist = bits (this_instr, 0, 14); |
| offset = bitcount (reglist) * 4; |
| if (bit (this_instr, 24)) /* pre */ |
| offset += 4; |
| } |
| else if (bit (this_instr, 24)) |
| offset = -4; |
| |
| { |
| unsigned long rn_val = |
| read_register (bits (this_instr, 16, 19)); |
| nextpc = |
| (CORE_ADDR) read_memory_integer ((CORE_ADDR) (rn_val |
| + offset), |
| 4); |
| } |
| nextpc = ADDR_BITS_REMOVE (nextpc); |
| if (nextpc == pc) |
| error ("Infinite loop detected"); |
| } |
| } |
| break; |
| |
| case 0xb: /* branch & link */ |
| case 0xa: /* branch */ |
| { |
| nextpc = BranchDest (pc, this_instr); |
| |
| nextpc = ADDR_BITS_REMOVE (nextpc); |
| if (nextpc == pc) |
| error ("Infinite loop detected"); |
| break; |
| } |
| |
| case 0xc: |
| case 0xd: |
| case 0xe: /* coproc ops */ |
| case 0xf: /* SWI */ |
| break; |
| |
| default: |
| fprintf_filtered (gdb_stderr, "Bad bit-field extraction\n"); |
| return (pc); |
| } |
| } |
| |
| return nextpc; |
| } |
| |
| /* single_step() is called just before we want to resume the inferior, |
| if we want to single-step it but there is no hardware or kernel |
| single-step support. We find the target of the coming instruction |
| and breakpoint it. |
| |
| single_step() is also called just after the inferior stops. If we |
| had set up a simulated single-step, we undo our damage. */ |
| |
| static void |
| arm_software_single_step (enum target_signal sig, int insert_bpt) |
| { |
| static int next_pc; /* State between setting and unsetting. */ |
| static char break_mem[BREAKPOINT_MAX]; /* Temporary storage for mem@bpt */ |
| |
| if (insert_bpt) |
| { |
| next_pc = arm_get_next_pc (read_register (ARM_PC_REGNUM)); |
| target_insert_breakpoint (next_pc, break_mem); |
| } |
| else |
| target_remove_breakpoint (next_pc, break_mem); |
| } |
| |
| #include "bfd-in2.h" |
| #include "libcoff.h" |
| |
| static int |
| gdb_print_insn_arm (bfd_vma memaddr, disassemble_info *info) |
| { |
| if (arm_pc_is_thumb (memaddr)) |
| { |
| static asymbol *asym; |
| static combined_entry_type ce; |
| static struct coff_symbol_struct csym; |
| static struct _bfd fake_bfd; |
| static bfd_target fake_target; |
| |
| if (csym.native == NULL) |
| { |
| /* Create a fake symbol vector containing a Thumb symbol. |
| This is solely so that the code in print_insn_little_arm() |
| and print_insn_big_arm() in opcodes/arm-dis.c will detect |
| the presence of a Thumb symbol and switch to decoding |
| Thumb instructions. */ |
| |
| fake_target.flavour = bfd_target_coff_flavour; |
| fake_bfd.xvec = &fake_target; |
| ce.u.syment.n_sclass = C_THUMBEXTFUNC; |
| csym.native = &ce; |
| csym.symbol.the_bfd = &fake_bfd; |
| csym.symbol.name = "fake"; |
| asym = (asymbol *) & csym; |
| } |
| |
| memaddr = UNMAKE_THUMB_ADDR (memaddr); |
| info->symbols = &asym; |
| } |
| else |
| info->symbols = NULL; |
| |
| if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| return print_insn_big_arm (memaddr, info); |
| else |
| return print_insn_little_arm (memaddr, info); |
| } |
| |
| /* The following define instruction sequences that will cause ARM |
| cpu's to take an undefined instruction trap. These are used to |
| signal a breakpoint to GDB. |
| |
| The newer ARMv4T cpu's are capable of operating in ARM or Thumb |
| modes. A different instruction is required for each mode. The ARM |
| cpu's can also be big or little endian. Thus four different |
| instructions are needed to support all cases. |
| |
| Note: ARMv4 defines several new instructions that will take the |
| undefined instruction trap. ARM7TDMI is nominally ARMv4T, but does |
| not in fact add the new instructions. The new undefined |
| instructions in ARMv4 are all instructions that had no defined |
| behaviour in earlier chips. There is no guarantee that they will |
| raise an exception, but may be treated as NOP's. In practice, it |
| may only safe to rely on instructions matching: |
| |
| 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 |
| 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 |
| C C C C 0 1 1 x x x x x x x x x x x x x x x x x x x x 1 x x x x |
| |
| Even this may only true if the condition predicate is true. The |
| following use a condition predicate of ALWAYS so it is always TRUE. |
| |
| There are other ways of forcing a breakpoint. GNU/Linux, RISC iX, |
| and NetBSD all use a software interrupt rather than an undefined |
| instruction to force a trap. This can be handled by by the |
| abi-specific code during establishment of the gdbarch vector. */ |
| |
| |
| /* NOTE rearnsha 2002-02-18: for now we allow a non-multi-arch gdb to |
| override these definitions. */ |
| #ifndef ARM_LE_BREAKPOINT |
| #define ARM_LE_BREAKPOINT {0xFE,0xDE,0xFF,0xE7} |
| #endif |
| #ifndef ARM_BE_BREAKPOINT |
| #define ARM_BE_BREAKPOINT {0xE7,0xFF,0xDE,0xFE} |
| #endif |
| #ifndef THUMB_LE_BREAKPOINT |
| #define THUMB_LE_BREAKPOINT {0xfe,0xdf} |
| #endif |
| #ifndef THUMB_BE_BREAKPOINT |
| #define THUMB_BE_BREAKPOINT {0xdf,0xfe} |
| #endif |
| |
| static const char arm_default_arm_le_breakpoint[] = ARM_LE_BREAKPOINT; |
| static const char arm_default_arm_be_breakpoint[] = ARM_BE_BREAKPOINT; |
| static const char arm_default_thumb_le_breakpoint[] = THUMB_LE_BREAKPOINT; |
| static const char arm_default_thumb_be_breakpoint[] = THUMB_BE_BREAKPOINT; |
| |
| /* Determine the type and size of breakpoint to insert at PCPTR. Uses |
| the program counter value to determine whether a 16-bit or 32-bit |
| breakpoint should be used. It returns a pointer to a string of |
| bytes that encode a breakpoint instruction, stores the length of |
| the string to *lenptr, and adjusts the program counter (if |
| necessary) to point to the actual memory location where the |
| breakpoint should be inserted. */ |
| |
| /* XXX ??? from old tm-arm.h: if we're using RDP, then we're inserting |
| breakpoints and storing their handles instread of what was in |
| memory. It is nice that this is the same size as a handle - |
| otherwise remote-rdp will have to change. */ |
| |
| static const unsigned char * |
| arm_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| |
| if (arm_pc_is_thumb (*pcptr) || arm_pc_is_thumb_dummy (*pcptr)) |
| { |
| *pcptr = UNMAKE_THUMB_ADDR (*pcptr); |
| *lenptr = tdep->thumb_breakpoint_size; |
| return tdep->thumb_breakpoint; |
| } |
| else |
| { |
| *lenptr = tdep->arm_breakpoint_size; |
| return tdep->arm_breakpoint; |
| } |
| } |
| |
| /* Extract from an array REGBUF containing the (raw) register state a |
| function return value of type TYPE, and copy that, in virtual |
| format, into VALBUF. */ |
| |
| static void |
| arm_extract_return_value (struct type *type, |
| char regbuf[REGISTER_BYTES], |
| char *valbuf) |
| { |
| if (TYPE_CODE_FLT == TYPE_CODE (type)) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| |
| switch (tdep->fp_model) |
| { |
| case ARM_FLOAT_FPA: |
| convert_from_extended (®buf[REGISTER_BYTE (ARM_F0_REGNUM)], |
| valbuf); |
| break; |
| |
| case ARM_FLOAT_SOFT: |
| case ARM_FLOAT_SOFT_VFP: |
| memcpy (valbuf, ®buf[REGISTER_BYTE (ARM_A1_REGNUM)], |
| TYPE_LENGTH (type)); |
| break; |
| |
| default: |
| internal_error |
| (__FILE__, __LINE__, |
| "arm_extract_return_value: Floating point model not supported"); |
| break; |
| } |
| } |
| else |
| memcpy (valbuf, ®buf[REGISTER_BYTE (ARM_A1_REGNUM)], |
| TYPE_LENGTH (type)); |
| } |
| |
| /* Extract from an array REGBUF containing the (raw) register state |
| the address in which a function should return its structure value. */ |
| |
| static CORE_ADDR |
| arm_extract_struct_value_address (struct regcache *regcache) |
| { |
| ULONGEST ret; |
| |
| regcache_cooked_read_unsigned (regcache, ARM_A1_REGNUM, &ret); |
| return ret; |
| } |
| |
| /* Will a function return an aggregate type in memory or in a |
| register? Return 0 if an aggregate type can be returned in a |
| register, 1 if it must be returned in memory. */ |
| |
| static int |
| arm_use_struct_convention (int gcc_p, struct type *type) |
| { |
| int nRc; |
| register enum type_code code; |
| |
| /* In the ARM ABI, "integer" like aggregate types are returned in |
| registers. For an aggregate type to be integer like, its size |
| must be less than or equal to REGISTER_SIZE and the offset of |
| each addressable subfield must be zero. Note that bit fields are |
| not addressable, and all addressable subfields of unions always |
| start at offset zero. |
| |
| This function is based on the behaviour of GCC 2.95.1. |
| See: gcc/arm.c: arm_return_in_memory() for details. |
| |
| Note: All versions of GCC before GCC 2.95.2 do not set up the |
| parameters correctly for a function returning the following |
| structure: struct { float f;}; This should be returned in memory, |
| not a register. Richard Earnshaw sent me a patch, but I do not |
| know of any way to detect if a function like the above has been |
| compiled with the correct calling convention. */ |
| |
| /* All aggregate types that won't fit in a register must be returned |
| in memory. */ |
| if (TYPE_LENGTH (type) > REGISTER_SIZE) |
| { |
| return 1; |
| } |
| |
| /* The only aggregate types that can be returned in a register are |
| structs and unions. Arrays must be returned in memory. */ |
| code = TYPE_CODE (type); |
| if ((TYPE_CODE_STRUCT != code) && (TYPE_CODE_UNION != code)) |
| { |
| return 1; |
| } |
| |
| /* Assume all other aggregate types can be returned in a register. |
| Run a check for structures, unions and arrays. */ |
| nRc = 0; |
| |
| if ((TYPE_CODE_STRUCT == code) || (TYPE_CODE_UNION == code)) |
| { |
| int i; |
| /* Need to check if this struct/union is "integer" like. For |
| this to be true, its size must be less than or equal to |
| REGISTER_SIZE and the offset of each addressable subfield |
| must be zero. Note that bit fields are not addressable, and |
| unions always start at offset zero. If any of the subfields |
| is a floating point type, the struct/union cannot be an |
| integer type. */ |
| |
| /* For each field in the object, check: |
| 1) Is it FP? --> yes, nRc = 1; |
| 2) Is it addressable (bitpos != 0) and |
| not packed (bitsize == 0)? |
| --> yes, nRc = 1 |
| */ |
| |
| for (i = 0; i < TYPE_NFIELDS (type); i++) |
| { |
| enum type_code field_type_code; |
| field_type_code = TYPE_CODE (TYPE_FIELD_TYPE (type, i)); |
| |
| /* Is it a floating point type field? */ |
| if (field_type_code == TYPE_CODE_FLT) |
| { |
| nRc = 1; |
| break; |
| } |
| |
| /* If bitpos != 0, then we have to care about it. */ |
| if (TYPE_FIELD_BITPOS (type, i) != 0) |
| { |
| /* Bitfields are not addressable. If the field bitsize is |
| zero, then the field is not packed. Hence it cannot be |
| a bitfield or any other packed type. */ |
| if (TYPE_FIELD_BITSIZE (type, i) == 0) |
| { |
| nRc = 1; |
| break; |
| } |
| } |
| } |
| } |
| |
| return nRc; |
| } |
| |
| /* Write into appropriate registers a function return value of type |
| TYPE, given in virtual format. */ |
| |
| static void |
| arm_store_return_value (struct type *type, char *valbuf) |
| { |
| if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| char buf[ARM_MAX_REGISTER_RAW_SIZE]; |
| |
| switch (tdep->fp_model) |
| { |
| case ARM_FLOAT_FPA: |
| |
| convert_to_extended (valbuf, buf); |
| write_register_bytes (REGISTER_BYTE (ARM_F0_REGNUM), buf, |
| FP_REGISTER_RAW_SIZE); |
| break; |
| |
| case ARM_FLOAT_SOFT: |
| case ARM_FLOAT_SOFT_VFP: |
| write_register_bytes (ARM_A1_REGNUM, valbuf, TYPE_LENGTH (type)); |
| break; |
| |
| default: |
| internal_error |
| (__FILE__, __LINE__, |
| "arm_store_return_value: Floating point model not supported"); |
| break; |
| } |
| } |
| else |
| write_register_bytes (ARM_A1_REGNUM, valbuf, TYPE_LENGTH (type)); |
| } |
| |
| /* Store the address of the place in which to copy the structure the |
| subroutine will return. This is called from call_function. */ |
| |
| static void |
| arm_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) |
| { |
| write_register (ARM_A1_REGNUM, addr); |
| } |
| |
| static int |
| arm_get_longjmp_target (CORE_ADDR *pc) |
| { |
| CORE_ADDR jb_addr; |
| char buf[INT_REGISTER_RAW_SIZE]; |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| |
| jb_addr = read_register (ARM_A1_REGNUM); |
| |
| if (target_read_memory (jb_addr + tdep->jb_pc * tdep->jb_elt_size, buf, |
| INT_REGISTER_RAW_SIZE)) |
| return 0; |
| |
| *pc = extract_address (buf, INT_REGISTER_RAW_SIZE); |
| return 1; |
| } |
| |
| /* Return non-zero if the PC is inside a thumb call thunk. */ |
| |
| int |
| arm_in_call_stub (CORE_ADDR pc, char *name) |
| { |
| CORE_ADDR start_addr; |
| |
| /* Find the starting address of the function containing the PC. If |
| the caller didn't give us a name, look it up at the same time. */ |
| if (0 == find_pc_partial_function (pc, name ? NULL : &name, |
| &start_addr, NULL)) |
| return 0; |
| |
| return strncmp (name, "_call_via_r", 11) == 0; |
| } |
| |
| /* If PC is in a Thumb call or return stub, return the address of the |
| target PC, which is in a register. The thunk functions are called |
| _called_via_xx, where x is the register name. The possible names |
| are r0-r9, sl, fp, ip, sp, and lr. */ |
| |
| CORE_ADDR |
| arm_skip_stub (CORE_ADDR pc) |
| { |
| char *name; |
| CORE_ADDR start_addr; |
| |
| /* Find the starting address and name of the function containing the PC. */ |
| if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0) |
| return 0; |
| |
| /* Call thunks always start with "_call_via_". */ |
| if (strncmp (name, "_call_via_", 10) == 0) |
| { |
| /* Use the name suffix to determine which register contains the |
| target PC. */ |
| static char *table[15] = |
| {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| "r8", "r9", "sl", "fp", "ip", "sp", "lr" |
| }; |
| int regno; |
| |
| for (regno = 0; regno <= 14; regno++) |
| if (strcmp (&name[10], table[regno]) == 0) |
| return read_register (regno); |
| } |
| |
| return 0; /* not a stub */ |
| } |
| |
| /* If the user changes the register disassembly flavor used for info |
| register and other commands, we have to also switch the flavor used |
| in opcodes for disassembly output. This function is run in the set |
| disassembly_flavor command, and does that. */ |
| |
| static void |
| set_disassembly_flavor_sfunc (char *args, int from_tty, |
| struct cmd_list_element *c) |
| { |
| set_disassembly_flavor (); |
| } |
| |
| /* Return the ARM register name corresponding to register I. */ |
| static const char * |
| arm_register_name (int i) |
| { |
| return arm_register_names[i]; |
| } |
| |
| static void |
| set_disassembly_flavor (void) |
| { |
| const char *setname, *setdesc, **regnames; |
| int numregs, j; |
| |
| /* Find the flavor that the user wants in the opcodes table. */ |
| int current = 0; |
| numregs = get_arm_regnames (current, &setname, &setdesc, ®names); |
| while ((disassembly_flavor != setname) |
| && (current < num_flavor_options)) |
| get_arm_regnames (++current, &setname, &setdesc, ®names); |
| current_option = current; |
| |
| /* Fill our copy. */ |
| for (j = 0; j < numregs; j++) |
| arm_register_names[j] = (char *) regnames[j]; |
| |
| /* Adjust case. */ |
| if (isupper (*regnames[ARM_PC_REGNUM])) |
| { |
| arm_register_names[ARM_FPS_REGNUM] = "FPS"; |
| arm_register_names[ARM_PS_REGNUM] = "CPSR"; |
| } |
| else |
| { |
| arm_register_names[ARM_FPS_REGNUM] = "fps"; |
| arm_register_names[ARM_PS_REGNUM] = "cpsr"; |
| } |
| |
| /* Synchronize the disassembler. */ |
| set_arm_regname_option (current); |
| } |
| |
| /* arm_othernames implements the "othernames" command. This is kind |
| of hacky, and I prefer the set-show disassembly-flavor which is |
| also used for the x86 gdb. I will keep this around, however, in |
| case anyone is actually using it. */ |
| |
| static void |
| arm_othernames (char *names, int n) |
| { |
| /* Circle through the various flavors. */ |
| current_option = (current_option + 1) % num_flavor_options; |
| |
| disassembly_flavor = valid_flavors[current_option]; |
| set_disassembly_flavor (); |
| } |
| |
| /* Fetch, and possibly build, an appropriate link_map_offsets structure |
| for ARM linux targets using the struct offsets defined in <link.h>. |
| Note, however, that link.h is not actually referred to in this file. |
| Instead, the relevant structs offsets were obtained from examining |
| link.h. (We can't refer to link.h from this file because the host |
| system won't necessarily have it, or if it does, the structs which |
| it defines will refer to the host system, not the target). */ |
| |
| struct link_map_offsets * |
| arm_linux_svr4_fetch_link_map_offsets (void) |
| { |
| static struct link_map_offsets lmo; |
| static struct link_map_offsets *lmp = 0; |
| |
| if (lmp == 0) |
| { |
| lmp = &lmo; |
| |
| lmo.r_debug_size = 8; /* Actual size is 20, but this is all we |
| need. */ |
| |
| lmo.r_map_offset = 4; |
| lmo.r_map_size = 4; |
| |
| lmo.link_map_size = 20; /* Actual size is 552, but this is all we |
| need. */ |
| |
| lmo.l_addr_offset = 0; |
| lmo.l_addr_size = 4; |
| |
| lmo.l_name_offset = 4; |
| lmo.l_name_size = 4; |
| |
| lmo.l_next_offset = 12; |
| lmo.l_next_size = 4; |
| |
| lmo.l_prev_offset = 16; |
| lmo.l_prev_size = 4; |
| } |
| |
| return lmp; |
| } |
| |
| /* Test whether the coff symbol specific value corresponds to a Thumb |
| function. */ |
| |
| static int |
| coff_sym_is_thumb (int val) |
| { |
| return (val == C_THUMBEXT || |
| val == C_THUMBSTAT || |
| val == C_THUMBEXTFUNC || |
| val == C_THUMBSTATFUNC || |
| val == C_THUMBLABEL); |
| } |
| |
| /* arm_coff_make_msymbol_special() |
| arm_elf_make_msymbol_special() |
| |
| These functions test whether the COFF or ELF symbol corresponds to |
| an address in thumb code, and set a "special" bit in a minimal |
| symbol to indicate that it does. */ |
| |
| static void |
| arm_elf_make_msymbol_special(asymbol *sym, struct minimal_symbol *msym) |
| { |
| /* Thumb symbols are of type STT_LOPROC, (synonymous with |
| STT_ARM_TFUNC). */ |
| if (ELF_ST_TYPE (((elf_symbol_type *)sym)->internal_elf_sym.st_info) |
| == STT_LOPROC) |
| MSYMBOL_SET_SPECIAL (msym); |
| } |
| |
| static void |
| arm_coff_make_msymbol_special(int val, struct minimal_symbol *msym) |
| { |
| if (coff_sym_is_thumb (val)) |
| MSYMBOL_SET_SPECIAL (msym); |
| } |
| |
| |
| static enum gdb_osabi |
| arm_elf_osabi_sniffer (bfd *abfd) |
| { |
| unsigned int elfosabi, eflags; |
| enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; |
| |
| elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI]; |
| |
| switch (elfosabi) |
| { |
| case ELFOSABI_NONE: |
| /* When elfosabi is ELFOSABI_NONE (0), then the ELF structures in the |
| file are conforming to the base specification for that machine |
| (there are no OS-specific extensions). In order to determine the |
| real OS in use we must look for OS notes that have been added. */ |
| bfd_map_over_sections (abfd, |
| generic_elf_osabi_sniff_abi_tag_sections, |
| &osabi); |
| if (osabi == GDB_OSABI_UNKNOWN) |
| { |
| /* Existing ARM tools don't set this field, so look at the EI_FLAGS |
| field for more information. */ |
| eflags = EF_ARM_EABI_VERSION(elf_elfheader(abfd)->e_flags); |
| switch (eflags) |
| { |
| case EF_ARM_EABI_VER1: |
| osabi = GDB_OSABI_ARM_EABI_V1; |
| break; |
| |
| case EF_ARM_EABI_VER2: |
| osabi = GDB_OSABI_ARM_EABI_V2; |
| break; |
| |
| case EF_ARM_EABI_UNKNOWN: |
| /* Assume GNU tools. */ |
| osabi = GDB_OSABI_ARM_APCS; |
| break; |
| |
| default: |
| internal_error (__FILE__, __LINE__, |
| "arm_elf_osabi_sniffer: Unknown ARM EABI " |
| "version 0x%x", eflags); |
| } |
| } |
| break; |
| |
| case ELFOSABI_ARM: |
| /* GNU tools use this value. Check note sections in this case, |
| as well. */ |
| bfd_map_over_sections (abfd, |
| generic_elf_osabi_sniff_abi_tag_sections, |
| &osabi); |
| if (osabi == GDB_OSABI_UNKNOWN) |
| { |
| /* Assume APCS ABI. */ |
| osabi = GDB_OSABI_ARM_APCS; |
| } |
| break; |
| |
| case ELFOSABI_FREEBSD: |
| osabi = GDB_OSABI_FREEBSD_ELF; |
| break; |
| |
| case ELFOSABI_NETBSD: |
| osabi = GDB_OSABI_NETBSD_ELF; |
| break; |
| |
| case ELFOSABI_LINUX: |
| osabi = GDB_OSABI_LINUX; |
| break; |
| } |
| |
| return osabi; |
| } |
| |
| |
| /* Initialize the current architecture based on INFO. If possible, |
| re-use an architecture from ARCHES, which is a list of |
| architectures already created during this debugging session. |
| |
| Called e.g. at program startup, when reading a core file, and when |
| reading a binary file. */ |
| |
| static struct gdbarch * |
| arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| { |
| struct gdbarch_tdep *tdep; |
| struct gdbarch *gdbarch; |
| enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; |
| |
| /* Try to deterimine the ABI of the object we are loading. */ |
| |
| if (info.abfd != NULL) |
| { |
| osabi = gdbarch_lookup_osabi (info.abfd); |
| if (osabi == GDB_OSABI_UNKNOWN) |
| { |
| switch (bfd_get_flavour (info.abfd)) |
| { |
| case bfd_target_aout_flavour: |
| /* Assume it's an old APCS-style ABI. */ |
| osabi = GDB_OSABI_ARM_APCS; |
| break; |
| |
| case bfd_target_coff_flavour: |
| /* Assume it's an old APCS-style ABI. */ |
| /* XXX WinCE? */ |
| osabi = GDB_OSABI_ARM_APCS; |
| break; |
| |
| default: |
| /* Leave it as "unknown". */ |
| } |
| } |
| } |
| |
| /* Find a candidate among extant architectures. */ |
| for (arches = gdbarch_list_lookup_by_info (arches, &info); |
| arches != NULL; |
| arches = gdbarch_list_lookup_by_info (arches->next, &info)) |
| { |
| /* Make sure the ABI selection matches. */ |
| tdep = gdbarch_tdep (arches->gdbarch); |
| if (tdep && tdep->osabi == osabi) |
| return arches->gdbarch; |
| } |
| |
| tdep = xmalloc (sizeof (struct gdbarch_tdep)); |
| gdbarch = gdbarch_alloc (&info, tdep); |
| |
| tdep->osabi = osabi; |
| |
| /* This is the way it has always defaulted. */ |
| tdep->fp_model = ARM_FLOAT_FPA; |
| |
| /* Breakpoints. */ |
| switch (info.byte_order) |
| { |
| case BFD_ENDIAN_BIG: |
| tdep->arm_breakpoint = arm_default_arm_be_breakpoint; |
| tdep->arm_breakpoint_size = sizeof (arm_default_arm_be_breakpoint); |
| tdep->thumb_breakpoint = arm_default_thumb_be_breakpoint; |
| tdep->thumb_breakpoint_size = sizeof (arm_default_thumb_be_breakpoint); |
| |
| break; |
| |
| case BFD_ENDIAN_LITTLE: |
| tdep->arm_breakpoint = arm_default_arm_le_breakpoint; |
| tdep->arm_breakpoint_size = sizeof (arm_default_arm_le_breakpoint); |
| tdep->thumb_breakpoint = arm_default_thumb_le_breakpoint; |
| tdep->thumb_breakpoint_size = sizeof (arm_default_thumb_le_breakpoint); |
| |
| break; |
| |
| default: |
| internal_error (__FILE__, __LINE__, |
| "arm_gdbarch_init: bad byte order for float format"); |
| } |
| |
| /* On ARM targets char defaults to unsigned. */ |
| set_gdbarch_char_signed (gdbarch, 0); |
| |
| /* This should be low enough for everything. */ |
| tdep->lowest_pc = 0x20; |
| tdep->jb_pc = -1; /* Longjump support not enabled by default. */ |
| |
| #if OLD_STYLE_ARM_DUMMY_FRAMES |
| /* NOTE: cagney/2002-05-07: Enable the below to restore the old ARM |
| specific (non-generic) dummy frame code. Might be useful if |
| there appears to be a problem with the generic dummy frame |
| mechanism that replaced it. */ |
| set_gdbarch_use_generic_dummy_frames (gdbarch, 0); |
| |
| /* Call dummy code. */ |
| set_gdbarch_call_dummy_location (gdbarch, ON_STACK); |
| set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1); |
| /* We have to give this a value now, even though we will re-set it |
| during each call to arm_fix_call_dummy. */ |
| set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 8); |
| set_gdbarch_call_dummy_p (gdbarch, 1); |
| set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0); |
| |
| set_gdbarch_call_dummy_words (gdbarch, arm_call_dummy_words); |
| set_gdbarch_sizeof_call_dummy_words (gdbarch, sizeof (arm_call_dummy_words)); |
| set_gdbarch_call_dummy_start_offset (gdbarch, 0); |
| set_gdbarch_call_dummy_length (gdbarch, 0); |
| |
| set_gdbarch_fix_call_dummy (gdbarch, arm_fix_call_dummy); |
| |
| set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_on_stack); |
| #else |
| set_gdbarch_use_generic_dummy_frames (gdbarch, 1); |
| set_gdbarch_call_dummy_location (gdbarch, AT_ENTRY_POINT); |
| |
| set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1); |
| set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0); |
| |
| set_gdbarch_call_dummy_p (gdbarch, 1); |
| set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0); |
| |
| set_gdbarch_call_dummy_words (gdbarch, arm_call_dummy_words); |
| set_gdbarch_sizeof_call_dummy_words (gdbarch, 0); |
| set_gdbarch_call_dummy_start_offset (gdbarch, 0); |
| set_gdbarch_call_dummy_length (gdbarch, 0); |
| |
| set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy); |
| set_gdbarch_pc_in_call_dummy (gdbarch, generic_pc_in_call_dummy); |
| |
| set_gdbarch_call_dummy_address (gdbarch, entry_point_address); |
| set_gdbarch_push_return_address (gdbarch, arm_push_return_address); |
| #endif |
| |
| set_gdbarch_get_saved_register (gdbarch, deprecated_generic_get_saved_register); |
| set_gdbarch_push_arguments (gdbarch, arm_push_arguments); |
| set_gdbarch_coerce_float_to_double (gdbarch, |
| standard_coerce_float_to_double); |
| |
| /* Frame handling. */ |
| set_gdbarch_frame_chain_valid (gdbarch, arm_frame_chain_valid); |
| set_gdbarch_init_extra_frame_info (gdbarch, arm_init_extra_frame_info); |
| set_gdbarch_read_fp (gdbarch, arm_read_fp); |
| set_gdbarch_frame_chain (gdbarch, arm_frame_chain); |
| set_gdbarch_frameless_function_invocation |
| (gdbarch, arm_frameless_function_invocation); |
| set_gdbarch_frame_saved_pc (gdbarch, arm_frame_saved_pc); |
| set_gdbarch_frame_args_address (gdbarch, arm_frame_args_address); |
| set_gdbarch_frame_locals_address (gdbarch, arm_frame_locals_address); |
| set_gdbarch_frame_num_args (gdbarch, arm_frame_num_args); |
| set_gdbarch_frame_args_skip (gdbarch, 0); |
| set_gdbarch_frame_init_saved_regs (gdbarch, arm_frame_init_saved_regs); |
| #if OLD_STYLE_ARM_DUMMY_FRAMES |
| /* NOTE: cagney/2002-05-07: Enable the below to restore the old ARM |
| specific (non-generic) dummy frame code. Might be useful if |
| there appears to be a problem with the generic dummy frame |
| mechanism that replaced it. */ |
| set_gdbarch_push_dummy_frame (gdbarch, arm_push_dummy_frame); |
| #else |
| set_gdbarch_push_dummy_frame (gdbarch, generic_push_dummy_frame); |
| #endif |
| set_gdbarch_pop_frame (gdbarch, arm_pop_frame); |
| |
| /* Address manipulation. */ |
| set_gdbarch_smash_text_address (gdbarch, arm_smash_text_address); |
| set_gdbarch_addr_bits_remove (gdbarch, arm_addr_bits_remove); |
| |
| /* Offset from address of function to start of its code. */ |
| set_gdbarch_function_start_offset (gdbarch, 0); |
| |
| /* Advance PC across function entry code. */ |
| set_gdbarch_skip_prologue (gdbarch, arm_skip_prologue); |
| |
| /* Get the PC when a frame might not be available. */ |
| set_gdbarch_saved_pc_after_call (gdbarch, arm_saved_pc_after_call); |
| |
| /* The stack grows downward. */ |
| set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| |
| /* Breakpoint manipulation. */ |
| set_gdbarch_breakpoint_from_pc (gdbarch, arm_breakpoint_from_pc); |
| set_gdbarch_decr_pc_after_break (gdbarch, 0); |
| |
| /* Information about registers, etc. */ |
| set_gdbarch_print_float_info (gdbarch, arm_print_float_info); |
| set_gdbarch_fp_regnum (gdbarch, ARM_FP_REGNUM); /* ??? */ |
| set_gdbarch_sp_regnum (gdbarch, ARM_SP_REGNUM); |
| set_gdbarch_pc_regnum (gdbarch, ARM_PC_REGNUM); |
| set_gdbarch_register_byte (gdbarch, arm_register_byte); |
| set_gdbarch_register_bytes (gdbarch, |
| (NUM_GREGS * INT_REGISTER_RAW_SIZE |
| + NUM_FREGS * FP_REGISTER_RAW_SIZE |
| + NUM_SREGS * STATUS_REGISTER_SIZE)); |
| set_gdbarch_num_regs (gdbarch, NUM_GREGS + NUM_FREGS + NUM_SREGS); |
| set_gdbarch_register_raw_size (gdbarch, arm_register_raw_size); |
| set_gdbarch_register_virtual_size (gdbarch, arm_register_virtual_size); |
| set_gdbarch_max_register_raw_size (gdbarch, FP_REGISTER_RAW_SIZE); |
| set_gdbarch_max_register_virtual_size (gdbarch, FP_REGISTER_VIRTUAL_SIZE); |
| set_gdbarch_register_virtual_type (gdbarch, arm_register_type); |
| |
| /* Internal <-> external register number maps. */ |
| set_gdbarch_register_sim_regno (gdbarch, arm_register_sim_regno); |
| |
| /* Integer registers are 4 bytes. */ |
| set_gdbarch_register_size (gdbarch, 4); |
| set_gdbarch_register_name (gdbarch, arm_register_name); |
| |
| /* Returning results. */ |
| set_gdbarch_deprecated_extract_return_value (gdbarch, arm_extract_return_value); |
| set_gdbarch_deprecated_store_return_value (gdbarch, arm_store_return_value); |
| set_gdbarch_store_struct_return (gdbarch, arm_store_struct_return); |
| set_gdbarch_use_struct_convention (gdbarch, arm_use_struct_convention); |
| set_gdbarch_extract_struct_value_address (gdbarch, |
| arm_extract_struct_value_address); |
| |
| /* Single stepping. */ |
| /* XXX For an RDI target we should ask the target if it can single-step. */ |
| set_gdbarch_software_single_step (gdbarch, arm_software_single_step); |
| |
| /* Minsymbol frobbing. */ |
| set_gdbarch_elf_make_msymbol_special (gdbarch, arm_elf_make_msymbol_special); |
| set_gdbarch_coff_make_msymbol_special (gdbarch, |
| arm_coff_make_msymbol_special); |
| |
| /* Hook in the ABI-specific overrides, if they have been registered. */ |
| gdbarch_init_osabi (info, gdbarch, osabi); |
| |
| /* Now we have tuned the configuration, set a few final things, |
| based on what the OS ABI has told us. */ |
| |
| if (tdep->jb_pc >= 0) |
| set_gdbarch_get_longjmp_target (gdbarch, arm_get_longjmp_target); |
| |
| /* Floating point sizes and format. */ |
| switch (info.byte_order) |
| { |
| case BFD_ENDIAN_BIG: |
| set_gdbarch_float_format (gdbarch, &floatformat_ieee_single_big); |
| set_gdbarch_double_format (gdbarch, &floatformat_ieee_double_big); |
| set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big); |
| |
| break; |
| |
| case BFD_ENDIAN_LITTLE: |
| set_gdbarch_float_format (gdbarch, &floatformat_ieee_single_little); |
| if (tdep->fp_model == ARM_FLOAT_VFP |
| || tdep->fp_model == ARM_FLOAT_SOFT_VFP) |
| { |
| set_gdbarch_double_format (gdbarch, &floatformat_ieee_double_little); |
| set_gdbarch_long_double_format (gdbarch, |
| &floatformat_ieee_double_little); |
| } |
| else |
| { |
| set_gdbarch_double_format |
| (gdbarch, &floatformat_ieee_double_littlebyte_bigword); |
| set_gdbarch_long_double_format |
| (gdbarch, &floatformat_ieee_double_littlebyte_bigword); |
| } |
| break; |
| |
| default: |
| internal_error (__FILE__, __LINE__, |
| "arm_gdbarch_init: bad byte order for float format"); |
| } |
| |
| /* We can't use SIZEOF_FRAME_SAVED_REGS here, since that still |
| references the old architecture vector, not the one we are |
| building here. */ |
| if (prologue_cache.saved_regs != NULL) |
| xfree (prologue_cache.saved_regs); |
| |
| /* We can't use NUM_REGS nor NUM_PSEUDO_REGS here, since that still |
| references the old architecture vector, not the one we are |
| building here. */ |
| prologue_cache.saved_regs = (CORE_ADDR *) |
| xcalloc (1, (sizeof (CORE_ADDR) |
| * (gdbarch_num_regs (gdbarch) |
| + gdbarch_num_pseudo_regs (gdbarch)))); |
| |
| return gdbarch; |
| } |
| |
| static void |
| arm_dump_tdep (struct gdbarch *current_gdbarch, struct ui_file *file) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| |
| if (tdep == NULL) |
| return; |
| |
| fprintf_unfiltered (file, "arm_dump_tdep: OS ABI = %s\n", |
| gdbarch_osabi_name (tdep->osabi)); |
| |
| fprintf_unfiltered (file, "arm_dump_tdep: Lowest pc = 0x%lx", |
| (unsigned long) tdep->lowest_pc); |
| } |
| |
| static void |
| arm_init_abi_eabi_v1 (struct gdbarch_info info, |
| struct gdbarch *gdbarch) |
| { |
| /* Place-holder. */ |
| } |
| |
| static void |
| arm_init_abi_eabi_v2 (struct gdbarch_info info, |
| struct gdbarch *gdbarch) |
| { |
| /* Place-holder. */ |
| } |
| |
| static void |
| arm_init_abi_apcs (struct gdbarch_info info, |
| struct gdbarch *gdbarch) |
| { |
| /* Place-holder. */ |
| } |
| |
| void |
| _initialize_arm_tdep (void) |
| { |
| struct ui_file *stb; |
| long length; |
| struct cmd_list_element *new_cmd; |
| const char *setname; |
| const char *setdesc; |
| const char **regnames; |
| int numregs, i, j; |
| static char *helptext; |
| |
| if (GDB_MULTI_ARCH) |
| gdbarch_register (bfd_arch_arm, arm_gdbarch_init, arm_dump_tdep); |
| |
| /* Register an ELF OS ABI sniffer for ARM binaries. */ |
| gdbarch_register_osabi_sniffer (bfd_arch_arm, |
| bfd_target_elf_flavour, |
| arm_elf_osabi_sniffer); |
| |
| /* Register some ABI variants for embedded systems. */ |
| gdbarch_register_osabi (bfd_arch_arm, GDB_OSABI_ARM_EABI_V1, |
| arm_init_abi_eabi_v1); |
| gdbarch_register_osabi (bfd_arch_arm, GDB_OSABI_ARM_EABI_V2, |
| arm_init_abi_eabi_v2); |
| gdbarch_register_osabi (bfd_arch_arm, GDB_OSABI_ARM_APCS, |
| arm_init_abi_apcs); |
| |
| tm_print_insn = gdb_print_insn_arm; |
| |
| /* Get the number of possible sets of register names defined in opcodes. */ |
| num_flavor_options = get_arm_regname_num_options (); |
| |
| /* Sync the opcode insn printer with our register viewer. */ |
| parse_arm_disassembler_option ("reg-names-std"); |
| |
| /* Begin creating the help text. */ |
| stb = mem_fileopen (); |
| fprintf_unfiltered (stb, "Set the disassembly flavor.\n\ |
| The valid values are:\n"); |
| |
| /* Initialize the array that will be passed to add_set_enum_cmd(). */ |
| valid_flavors = xmalloc ((num_flavor_options + 1) * sizeof (char *)); |
| for (i = 0; i < num_flavor_options; i++) |
| { |
| numregs = get_arm_regnames (i, &setname, &setdesc, ®names); |
| valid_flavors[i] = setname; |
| fprintf_unfiltered (stb, "%s - %s\n", setname, |
| setdesc); |
| /* Copy the default names (if found) and synchronize disassembler. */ |
| if (!strcmp (setname, "std")) |
| { |
| disassembly_flavor = setname; |
| current_option = i; |
| for (j = 0; j < numregs; j++) |
| arm_register_names[j] = (char *) regnames[j]; |
| set_arm_regname_option (i); |
| } |
| } |
| /* Mark the end of valid options. */ |
| valid_flavors[num_flavor_options] = NULL; |
| |
| /* Finish the creation of the help text. */ |
| fprintf_unfiltered (stb, "The default is \"std\"."); |
| helptext = ui_file_xstrdup (stb, &length); |
| ui_file_delete (stb); |
| |
| /* Add the disassembly-flavor command. */ |
| new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class, |
| valid_flavors, |
| &disassembly_flavor, |
| helptext, |
| &setlist); |
| set_cmd_sfunc (new_cmd, set_disassembly_flavor_sfunc); |
| add_show_from_set (new_cmd, &showlist); |
| |
| /* ??? Maybe this should be a boolean. */ |
| add_show_from_set (add_set_cmd ("apcs32", no_class, |
| var_zinteger, (char *) &arm_apcs_32, |
| "Set usage of ARM 32-bit mode.\n", &setlist), |
| &showlist); |
| |
| /* Add the deprecated "othernames" command. */ |
| |
| add_com ("othernames", class_obscure, arm_othernames, |
| "Switch to the next set of register names."); |
| |
| /* Fill in the prologue_cache fields. */ |
| prologue_cache.saved_regs = NULL; |
| prologue_cache.extra_info = (struct frame_extra_info *) |
| xcalloc (1, sizeof (struct frame_extra_info)); |
| |
| /* Debugging flag. */ |
| add_show_from_set (add_set_cmd ("arm", class_maintenance, var_zinteger, |
| &arm_debug, "Set arm debugging.\n\ |
| When non-zero, arm specific debugging is enabled.", &setdebuglist), |
| &showdebuglist); |
| } |