| /* Copyright (C) 2013-2021 Free Software Foundation, Inc. |
| Contributed by Altera and Mentor Graphics, Inc. |
| |
| This file 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 3, or (at your option) any |
| later version. |
| |
| This file 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. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* Set up trampolines. |
| R12 is the static chain register. |
| R2 is AT, the assembler temporary. |
| The trampoline code looks like: |
| movhi r12,%hi(chain) |
| ori r12,%lo(chain) |
| movhi r2,%hi(fn) |
| ori r2,%lo(fn) |
| jmp r2 |
| */ |
| |
| #define SC_REGNO 12 |
| |
| /* Instruction encodings depend on the ISA level. */ |
| #if __nios2_arch__ == 2 |
| #define MOVHI(reg,imm16) \ |
| (((reg) << 11) | ((imm16) << 16) | 0x34) |
| #define ORI(reg,imm16) \ |
| (((reg) << 11) | ((reg) << 6) | ((imm16) << 16) | 0x14) |
| #define JMP(reg) \ |
| (((reg) << 6) | (0x0d << 26) | 0x20) |
| |
| #elif __nios2_arch__ == 1 |
| #define MOVHI(reg,imm16) \ |
| (((reg) << 22) | ((imm16) << 6) | 0x34) |
| #define ORI(reg,imm16) \ |
| (((reg) << 27) | ((reg) << 22) | ((imm16) << 6) | 0x14) |
| #define JMP(reg) \ |
| (((reg) << 27) | (0x0d << 11) | 0x3a) |
| |
| #else |
| #error "Unknown Nios II architecture level" |
| #endif |
| |
| void |
| __trampoline_setup (unsigned int *addr, void *fnptr, void *chainptr) |
| { |
| unsigned int fn = (unsigned int) fnptr; |
| unsigned int chain = (unsigned int) chainptr; |
| int i; |
| |
| addr[0] = MOVHI (SC_REGNO, ((chain >> 16) & 0xffff)); |
| addr[1] = ORI (SC_REGNO, (chain & 0xffff)); |
| addr[2] = MOVHI (2, ((fn >> 16) & 0xffff)); |
| addr[3] = ORI (2, (fn & 0xffff)); |
| addr[4] = JMP (2); |
| |
| /* Flush the caches. |
| See Example 9-4 in the Nios II Software Developer's Handbook. */ |
| for (i = 0; i < 5; i++) |
| asm volatile ("flushd 0(%0); flushi %0" :: "r"(addr + i) : "memory"); |
| asm volatile ("flushp" ::: "memory"); |
| } |