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authorGiacomo Travaglini <giacomo.travaglini@arm.com>2018-02-13 14:01:57 +0000
committerGiacomo Travaglini <giacomo.travaglini@arm.com>2018-02-20 13:30:02 +0000
commit73dcf05f633b5e3a7d9a16338a64c1832ef38388 (patch)
treeb66442229292c0b699e5ae7f6c1b236648c21a87 /src/arch/arm/isa
parent26b03914d7dbcf6b6c8c0a9c08d4e3ff81365376 (diff)
downloadgem5-73dcf05f633b5e3a7d9a16338a64c1832ef38388.tar.xz
arch-arm: Add AArch32 HLT Semihosting interface
AArch32 HLT instruction is now able to issue Arm Semihosting commands as the AArch64 counterpart in either Arm and Thumb mode. Change-Id: I77da73d2e6a9288c704a5f646f4447022517ceb6 Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8372 Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Diffstat (limited to 'src/arch/arm/isa')
-rw-r--r--src/arch/arm/isa/decoder/arm.isa4
-rw-r--r--src/arch/arm/isa/formats/breakpoint.isa16
-rw-r--r--src/arch/arm/isa/formats/data.isa32
-rw-r--r--src/arch/arm/isa/insts/misc.isa25
4 files changed, 60 insertions, 17 deletions
diff --git a/src/arch/arm/isa/decoder/arm.isa b/src/arch/arm/isa/decoder/arm.isa
index 9b8b37a9c..1a32ce6b6 100644
--- a/src/arch/arm/isa/decoder/arm.isa
+++ b/src/arch/arm/isa/decoder/arm.isa
@@ -1,6 +1,6 @@
// -*- mode:c++ -*-
-// Copyright (c) 2010-2013,2017 ARM Limited
+// Copyright (c) 2010-2013,2017-2018 ARM Limited
// All rights reserved
//
// The license below extends only to copyright in the software and shall
@@ -76,7 +76,7 @@ format DataOp {
0x5: ArmSatAddSub::armSatAddSub();
0x6: ArmERet::armERet();
0x7: decode OPCODE_22 {
- 0: Breakpoint::bkpt();
+ 0: ArmBkptHlt::armBkptHlt();
1: ArmSmcHyp::armSmcHyp();
}
}
diff --git a/src/arch/arm/isa/formats/breakpoint.isa b/src/arch/arm/isa/formats/breakpoint.isa
index a22f2de7a..4db470b1e 100644
--- a/src/arch/arm/isa/formats/breakpoint.isa
+++ b/src/arch/arm/isa/formats/breakpoint.isa
@@ -1,6 +1,6 @@
// -*- mode:c++ -*-
-// Copyright (c) 2010 ARM Limited
+// Copyright (c) 2010,2018 ARM Limited
// All rights reserved
//
// The license below extends only to copyright in the software and shall
@@ -87,7 +87,17 @@ output exec {{
}
}};
-def format Breakpoint() {{
- decode_block = 'return new Breakpoint(machInst);\n'
+def format ArmBkptHlt() {{
+ decode_block = '''
+ {
+ if (bits(machInst, 21)) {
+ return new Breakpoint(machInst);
+ } else {
+ uint32_t imm16 = (bits(machInst, 19, 8) << 4) |
+ (bits(machInst, 3, 0) << 0);
+ return new Hlt(machInst, imm16);
+ }
+ }
+ '''
}};
diff --git a/src/arch/arm/isa/formats/data.isa b/src/arch/arm/isa/formats/data.isa
index 909a52593..eab081827 100644
--- a/src/arch/arm/isa/formats/data.isa
+++ b/src/arch/arm/isa/formats/data.isa
@@ -1,4 +1,4 @@
-// Copyright (c) 2010,2017 ARM Limited
+// Copyright (c) 2010,2017-2018 ARM Limited
// All rights reserved
//
// The license below extends only to copyright in the software and shall
@@ -1199,17 +1199,25 @@ def format Thumb16Misc() {{
}
case 0xa:
{
- IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 2, 0);
- IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 5, 3);
- switch (bits(machInst, 7, 6)) {
- case 0x0:
- return new Rev(machInst, rd, rm);
- case 0x1:
- return new Rev16(machInst, rd, rm);
- case 0x3:
- return new Revsh(machInst, rd, rm);
- default:
- break;
+ const uint8_t op1 = bits(machInst, 7, 6);
+ if (op1 == 0x2) {
+ return new Hlt(machInst, bits(machInst, 5, 0));
+ } else {
+ IntRegIndex rd =
+ (IntRegIndex)(uint32_t)bits(machInst, 2, 0);
+ IntRegIndex rm =
+ (IntRegIndex)(uint32_t)bits(machInst, 5, 3);
+
+ switch (op1) {
+ case 0x0:
+ return new Rev(machInst, rd, rm);
+ case 0x1:
+ return new Rev16(machInst, rd, rm);
+ case 0x3:
+ return new Revsh(machInst, rd, rm);
+ default:
+ break;
+ }
}
}
break;
diff --git a/src/arch/arm/isa/insts/misc.isa b/src/arch/arm/isa/insts/misc.isa
index 566ea4b9d..a183f5d0a 100644
--- a/src/arch/arm/isa/insts/misc.isa
+++ b/src/arch/arm/isa/insts/misc.isa
@@ -62,6 +62,31 @@ let {{
decoder_output = SemihostConstructor.subst(svcIop)
exec_output = PredOpExecute.subst(svcIop)
+ hltCode = '''
+ ThreadContext *tc = xc->tcBase();
+
+ const auto semihost_imm = Thumb? 0x3C : 0xF000;
+
+ if (ArmSystem::haveSemihosting(tc) && imm == semihost_imm) {
+ R0 = ArmSystem::callSemihosting32(tc, R0, R1);
+ } else {
+ // HLT instructions aren't implemented, so treat them as undefined
+ // instructions.
+ fault = std::make_shared<UndefinedInstruction>(
+ machInst, false, mnemonic);
+ }
+ '''
+
+ hltIop = InstObjParams("hlt", "Hlt", "ImmOp",
+ { "code": hltCode,
+ "predicate_test": predicateTest,
+ "thumb_semihost": '0x3C',
+ "arm_semihost": '0xF000' },
+ ["IsNonSpeculative"])
+ header_output += ImmOpDeclare.subst(hltIop)
+ decoder_output += SemihostConstructor.subst(hltIop)
+ exec_output += PredOpExecute.subst(hltIop)
+
smcCode = '''
HCR hcr = Hcr;
CPSR cpsr = Cpsr;