[Aarch64] Add Binutils support for MEC

This change supports MEC which is part of RME (Realm Management Extension).

gas/ChangeLog

diff --git a/gas/ChangeLog b/gas/ChangeLog
index c9a325e..1e00ce3 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,11 @@
+2023-02-28  Richard Ball  <richard.ball@arm.com>
+
+	* testsuite/gas/aarch64/mec-invalid.d: New test.
+	* testsuite/gas/aarch64/mec-invalid.l: New test.
+	* testsuite/gas/aarch64/mec-invalid.s: New test.
+	* testsuite/gas/aarch64/mec.d: New test.
+	* testsuite/gas/aarch64/mec.s: New test.
+
 2023-02-27  Benson Muite  <benson_muite@emailplus.org>
 
 	PR 28909

gas/testsuite/gas/aarch64/mec-invalid.d

diff --git a/gas/testsuite/gas/aarch64/mec-invalid.d b/gas/testsuite/gas/aarch64/mec-invalid.d
new file mode 100644
index 0000000..b071a34
--- /dev/null
+++ b/gas/testsuite/gas/aarch64/mec-invalid.d
@@ -0,0 +1,3 @@
+#name: Invalid MEC System registers usage
+#source: mec-invalid.s
+#warning_output: mec-invalid.l

gas/testsuite/gas/aarch64/mec-invalid.l

diff --git a/gas/testsuite/gas/aarch64/mec-invalid.l b/gas/testsuite/gas/aarch64/mec-invalid.l
new file mode 100644
index 0000000..9aeb7ee
--- /dev/null
+++ b/gas/testsuite/gas/aarch64/mec-invalid.l
@@ -0,0 +1,2 @@
+.*: Assembler messages:
+.*: Warning: specified register cannot be written to at operand 1.*

gas/testsuite/gas/aarch64/mec-invalid.s

diff --git a/gas/testsuite/gas/aarch64/mec-invalid.s b/gas/testsuite/gas/aarch64/mec-invalid.s
new file mode 100644
index 0000000..9f7f1cd
--- /dev/null
+++ b/gas/testsuite/gas/aarch64/mec-invalid.s
@@ -0,0 +1,4 @@
+// Memory Encryption Contexts, an extension of RME.
+
+// Illegal write to MEC system registers.
+msr mecidr_el2, x0

gas/testsuite/gas/aarch64/mec.d

diff --git a/gas/testsuite/gas/aarch64/mec.d b/gas/testsuite/gas/aarch64/mec.d
new file mode 100644
index 0000000..118575d
--- /dev/null
+++ b/gas/testsuite/gas/aarch64/mec.d
@@ -0,0 +1,24 @@
+#name: MEC System registers
+#objdump: -dr
+
+.*:     file format .*
+
+Disassembly of section .text:
+
+0+ <.*>:
+
+[^:]*:	d53ca8e0 	mrs	x0, mecidr_el2
+[^:]*:	d53ca800 	mrs	x0, mecid_p0_el2
+[^:]*:	d53ca820 	mrs	x0, mecid_a0_el2
+[^:]*:	d53ca840 	mrs	x0, mecid_p1_el2
+[^:]*:	d53ca860 	mrs	x0, mecid_a1_el2
+[^:]*:	d53ca900 	mrs	x0, vmecid_p_el2
+[^:]*:	d53ca920 	mrs	x0, vmecid_a_el2
+[^:]*:	d53eaa20 	mrs	x0, mecid_rl_a_el3
+[^:]*:	d51ca800 	msr	mecid_p0_el2, x0
+[^:]*:	d51ca820 	msr	mecid_a0_el2, x0
+[^:]*:	d51ca840 	msr	mecid_p1_el2, x0
+[^:]*:	d51ca860 	msr	mecid_a1_el2, x0
+[^:]*:	d51ca900 	msr	vmecid_p_el2, x0
+[^:]*:	d51ca920 	msr	vmecid_a_el2, x0
+[^:]*:	d51eaa20 	msr	mecid_rl_a_el3, x0

gas/testsuite/gas/aarch64/mec.s

diff --git a/gas/testsuite/gas/aarch64/mec.s b/gas/testsuite/gas/aarch64/mec.s
new file mode 100644
index 0000000..d89a274
--- /dev/null
+++ b/gas/testsuite/gas/aarch64/mec.s
@@ -0,0 +1,20 @@
+// Memory Encryption Contexts, an extension of RME.
+
+// Read from MEC system registers.
+mrs x0, mecidr_el2
+mrs x0, mecid_p0_el2
+mrs x0, mecid_a0_el2
+mrs x0, mecid_p1_el2
+mrs x0, mecid_a1_el2
+mrs x0, vmecid_p_el2
+mrs x0, vmecid_a_el2
+mrs x0, mecid_rl_a_el3
+
+// Write to MEC system registers.
+msr mecid_p0_el2, x0
+msr mecid_a0_el2, x0
+msr mecid_p1_el2, x0
+msr mecid_a1_el2, x0
+msr vmecid_p_el2, x0
+msr vmecid_a_el2, x0
+msr mecid_rl_a_el3, x0

opcodes/ChangeLog

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index a6e68d5..9cf68d7 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,7 @@
+2023-02-28  Richard Ball  <richard.ball@arm.com>
+
+	* aarch64-opc.c: Add MEC system registers.
+
 2023-01-03  Nick Clifton  <nickc@redhat.com>
 
 	* po/de.po: Updated German translation.

opcodes/aarch64-opc.c

diff --git a/opcodes/aarch64-opc.c b/opcodes/aarch64-opc.c
index 886beff..e271b0d 100644
--- a/opcodes/aarch64-opc.c
+++ b/opcodes/aarch64-opc.c
@@ -5010,6 +5010,15 @@
   SR_CORE ("gpccr_el3",     CPENC (3,6,C2,C1,6), 0),
   SR_CORE ("gptbr_el3",     CPENC (3,6,C2,C1,4), 0),
 
+  SR_CORE ("mecidr_el2",    CPENC (3,4,C10,C8,7),  F_REG_READ),
+  SR_CORE ("mecid_p0_el2",  CPENC (3,4,C10,C8,0),  0),
+  SR_CORE ("mecid_a0_el2",  CPENC (3,4,C10,C8,1),  0),
+  SR_CORE ("mecid_p1_el2",  CPENC (3,4,C10,C8,2),  0),
+  SR_CORE ("mecid_a1_el2",  CPENC (3,4,C10,C8,3),  0),
+  SR_CORE ("vmecid_p_el2",  CPENC (3,4,C10,C9,0),  0),
+  SR_CORE ("vmecid_a_el2",  CPENC (3,4,C10,C9,1),  0),
+  SR_CORE ("mecid_rl_a_el3",CPENC (3,6,C10,C10,1), 0),
+
   SR_SME ("svcr",             CPENC (3,3,C4,C2,2),  0),
   SR_SME ("id_aa64smfr0_el1", CPENC (3,0,C0,C4,5),  F_REG_READ),
   SR_SME ("smcr_el1",         CPENC (3,0,C1,C2,6),  0),