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target-arm: Add AArch64 translation stub
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We should translate AArch64 mode separately from AArch32 mode. In AArch64 mode,
registers look vastly different, instruction encoding is completely different,
basically the system turns into a different machine.

So let's do a simple if() in translate.c to decide whether we can handle the
current code in the legacy AArch32 code or in the new AArch64 code.

So far, the translation always complains about unallocated instructions. There
is no emulator functionality in this patch!

Signed-off-by: Alexander Graf <[email protected]>
Signed-off-by: John Rigby <[email protected]>
Signed-off-by: Peter Maydell <[email protected]>
Message-id: [email protected]
Message-id: [email protected]
[PMM:
 * provide no-op versions of a64 functions ifndef TARGET_AARCH64;
   this lets us avoid #ifdefs in translate.c
 * insert the missing call to disas_a64_insn()
 * stash the insn in the DisasContext rather than reloading it in
   real_unallocated_encoding()
]
Signed-off-by: Peter Maydell <[email protected]>
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agraf authored and pm215 committed Sep 10, 2013
1 parent 3926cc8 commit 14ade10
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Showing 6 changed files with 178 additions and 4 deletions.
2 changes: 1 addition & 1 deletion target-arm/Makefile.objs
Original file line number Diff line number Diff line change
Expand Up @@ -5,4 +5,4 @@ obj-$(CONFIG_NO_KVM) += kvm-stub.o
obj-y += translate.o op_helper.o helper.o cpu.o
obj-y += neon_helper.o iwmmxt_helper.o
obj-y += gdbstub.o
obj-$(TARGET_AARCH64) += cpu64.o
obj-$(TARGET_AARCH64) += cpu64.o translate-a64.o
5 changes: 5 additions & 0 deletions target-arm/cpu-qom.h
Original file line number Diff line number Diff line change
Expand Up @@ -173,4 +173,9 @@ int arm_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
void arm_gt_ptimer_cb(void *opaque);
void arm_gt_vtimer_cb(void *opaque);

#ifdef TARGET_AARCH64
void aarch64_cpu_dump_state(CPUState *cs, FILE *f,
fprintf_function cpu_fprintf, int flags);
#endif

#endif
3 changes: 3 additions & 0 deletions target-arm/cpu64.c
Original file line number Diff line number Diff line change
Expand Up @@ -70,6 +70,9 @@ static void aarch64_cpu_finalizefn(Object *obj)

static void aarch64_cpu_class_init(ObjectClass *oc, void *data)
{
CPUClass *cc = CPU_CLASS(oc);

cc->dump_state = aarch64_cpu_dump_state;
}

static void aarch64_cpu_register(const ARMCPUInfo *info)
Expand Down
139 changes: 139 additions & 0 deletions target-arm/translate-a64.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,139 @@
/*
* AArch64 translation
*
* Copyright (c) 2013 Alexander Graf <[email protected]>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>

#include "cpu.h"
#include "tcg-op.h"
#include "qemu/log.h"
#include "translate.h"
#include "qemu/host-utils.h"

#include "helper.h"
#define GEN_HELPER 1
#include "helper.h"

static TCGv_i64 cpu_X[32];
static TCGv_i64 cpu_pc;
static TCGv_i32 pstate;

static const char *regnames[] = {
"x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
"x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
"x16", "x17", "x18", "x19", "x20", "x21", "x22", "x23",
"x24", "x25", "x26", "x27", "x28", "x29", "lr", "sp"
};

/* initialize TCG globals. */
void a64_translate_init(void)
{
int i;

cpu_pc = tcg_global_mem_new_i64(TCG_AREG0,
offsetof(CPUARMState, pc),
"pc");
for (i = 0; i < 32; i++) {
cpu_X[i] = tcg_global_mem_new_i64(TCG_AREG0,
offsetof(CPUARMState, xregs[i]),
regnames[i]);
}

pstate = tcg_global_mem_new_i32(TCG_AREG0,
offsetof(CPUARMState, pstate),
"pstate");
}

void aarch64_cpu_dump_state(CPUState *cs, FILE *f,
fprintf_function cpu_fprintf, int flags)
{
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
int i;

cpu_fprintf(f, "PC=%016"PRIx64" SP=%016"PRIx64"\n",
env->pc, env->xregs[31]);
for (i = 0; i < 31; i++) {
cpu_fprintf(f, "X%02d=%016"PRIx64, i, env->xregs[i]);
if ((i % 4) == 3) {
cpu_fprintf(f, "\n");
} else {
cpu_fprintf(f, " ");
}
}
cpu_fprintf(f, "PSTATE=%c%c%c%c\n",
env->pstate & PSTATE_N ? 'n' : '.',
env->pstate & PSTATE_Z ? 'z' : '.',
env->pstate & PSTATE_C ? 'c' : '.',
env->pstate & PSTATE_V ? 'v' : '.');
cpu_fprintf(f, "\n");
}

void gen_a64_set_pc_im(uint64_t val)
{
tcg_gen_movi_i64(cpu_pc, val);
}

static void gen_exception(int excp)
{
TCGv_i32 tmp = tcg_temp_new_i32();
tcg_gen_movi_i32(tmp, excp);
gen_helper_exception(cpu_env, tmp);
tcg_temp_free_i32(tmp);
}

static void gen_exception_insn(DisasContext *s, int offset, int excp)
{
gen_a64_set_pc_im(s->pc - offset);
gen_exception(excp);
s->is_jmp = DISAS_JUMP;
}

static void real_unallocated_encoding(DisasContext *s)
{
fprintf(stderr, "Unknown instruction: %#x\n", s->insn);
gen_exception_insn(s, 4, EXCP_UDEF);
}

#define unallocated_encoding(s) do { \
fprintf(stderr, "unallocated encoding at line: %d\n", __LINE__); \
real_unallocated_encoding(s); \
} while (0)

void disas_a64_insn(CPUARMState *env, DisasContext *s)
{
uint32_t insn;

insn = arm_ldl_code(env, s->pc, s->bswap_code);
s->insn = insn;
s->pc += 4;

switch ((insn >> 24) & 0x1f) {
default:
unallocated_encoding(s);
break;
}

if (unlikely(s->singlestep_enabled) && (s->is_jmp == DISAS_TB_JUMP)) {
/* go through the main loop for single step */
s->is_jmp = DISAS_JUMP;
}
}
14 changes: 11 additions & 3 deletions target-arm/translate.c
Original file line number Diff line number Diff line change
Expand Up @@ -114,6 +114,8 @@ void arm_translate_init(void)
offsetof(CPUARMState, exclusive_info), "exclusive_info");
#endif

a64_translate_init();

#define GEN_HELPER 2
#include "helper.h"
}
Expand Down Expand Up @@ -907,7 +909,11 @@ DO_GEN_ST(st32)

static inline void gen_set_pc_im(DisasContext *s, target_ulong val)
{
tcg_gen_movi_i32(cpu_R[15], val);
if (s->aarch64) {
gen_a64_set_pc_im(val);
} else {
tcg_gen_movi_i32(cpu_R[15], val);
}
}

/* Force a TB lookup after an instruction that changes the CPU state. */
Expand Down Expand Up @@ -10099,7 +10105,7 @@ static inline void gen_intermediate_code_internal(ARMCPU *cpu,
do {
#ifdef CONFIG_USER_ONLY
/* Intercept jump to the magic kernel page. */
if (dc->pc >= 0xffff0000) {
if (!dc->aarch64 && dc->pc >= 0xffff0000) {
/* We always get here via a jump, so know we are not in a
conditional execution block. */
gen_exception(EXCP_KERNEL_TRAP);
Expand Down Expand Up @@ -10147,7 +10153,9 @@ static inline void gen_intermediate_code_internal(ARMCPU *cpu,
tcg_gen_debug_insn_start(dc->pc);
}

if (dc->thumb) {
if (dc->aarch64) {
disas_a64_insn(env, dc);
} else if (dc->thumb) {
disas_thumb_insn(env, dc);
if (dc->condexec_mask) {
dc->condexec_cond = (dc->condexec_cond & 0xe)
Expand Down
19 changes: 19 additions & 0 deletions target-arm/translate.h
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
/* internal defines */
typedef struct DisasContext {
target_ulong pc;
uint32_t insn;
int is_jmp;
/* Nonzero if this instruction has been conditionally skipped. */
int condjmp;
Expand All @@ -27,4 +28,22 @@ typedef struct DisasContext {

extern TCGv_ptr cpu_env;

#ifdef TARGET_AARCH64
void a64_translate_init(void);
void disas_a64_insn(CPUARMState *env, DisasContext *s);
void gen_a64_set_pc_im(uint64_t val);
#else
static inline void a64_translate_init(void)
{
}

static inline void disas_a64_insn(CPUARMState *env, DisasContext *s)
{
}

static inline void gen_a64_set_pc_im(uint64_t val)
{
}
#endif

#endif /* TARGET_ARM_TRANSLATE_H */

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