target-arm: implement SCTLR.B, drop bswap_code

bswap_code is a CPU property of sorts ("is the iside endianness the
opposite way round to TARGET_WORDS_BIGENDIAN?") but it is not the
actual CPU state involved here which is SCTLR.B (set for BE32
binaries, clear for BE8).

Replace bswap_code with SCTLR.B, and pass that to arm_ld*_code.
The next patches will make data fetches honor both SCTLR.B and
CPSR.E appropriately.

Backports commit f9fd40ebe4f55e0048e002925b8d65e66d56e7a7 from qemu
This commit is contained in:
Paolo Bonzini 2018-02-21 02:04:31 -05:00 committed by Lioncash
parent 64a9bec68a
commit ec15ee10d0
No known key found for this signature in database
GPG key ID: 4E3C3CC1031BA9C7
6 changed files with 57 additions and 30 deletions

View file

@ -25,10 +25,10 @@
/* Load an instruction and return it in the standard little-endian order */
static inline uint32_t arm_ldl_code(CPUARMState *env, target_ulong addr,
bool do_swap)
bool sctlr_b)
{
uint32_t insn = cpu_ldl_code(env, addr);
if (do_swap) {
if (bswap_code(sctlr_b)) {
return bswap32(insn);
}
return insn;
@ -36,10 +36,10 @@ static inline uint32_t arm_ldl_code(CPUARMState *env, target_ulong addr,
/* Ditto, for a halfword (Thumb) instruction */
static inline uint16_t arm_lduw_code(CPUARMState *env, target_ulong addr,
bool do_swap)
bool sctlr_b)
{
uint16_t insn = cpu_lduw_code(env, addr);
if (do_swap) {
if (bswap_code(sctlr_b)) {
return bswap16(insn);
}
return insn;

View file

@ -481,9 +481,6 @@ typedef struct CPUARMState {
uint32_t cregs[16];
} iwmmxt;
/* For mixed endian mode. */
bool bswap_code;
#if defined(CONFIG_USER_ONLY)
/* For usermode syscall translation. */
int eabi;
@ -1951,8 +1948,8 @@ static inline bool arm_singlestep_active(CPUARMState *env)
#define ARM_TBFLAG_VFPEN_MASK (1 << ARM_TBFLAG_VFPEN_SHIFT)
#define ARM_TBFLAG_CONDEXEC_SHIFT 8
#define ARM_TBFLAG_CONDEXEC_MASK (0xff << ARM_TBFLAG_CONDEXEC_SHIFT)
#define ARM_TBFLAG_BSWAP_CODE_SHIFT 16
#define ARM_TBFLAG_BSWAP_CODE_MASK (1 << ARM_TBFLAG_BSWAP_CODE_SHIFT)
#define ARM_TBFLAG_SCTLR_B_SHIFT 16
#define ARM_TBFLAG_SCTLR_B_MASK (1 << ARM_TBFLAG_SCTLR_B_SHIFT)
/* We store the bottom two bits of the CPAR as TB flags and handle
* checks on the other bits at runtime
*/
@ -1988,13 +1985,34 @@ static inline bool arm_singlestep_active(CPUARMState *env)
(((F) & ARM_TBFLAG_VFPEN_MASK) >> ARM_TBFLAG_VFPEN_SHIFT)
#define ARM_TBFLAG_CONDEXEC(F) \
(((F) & ARM_TBFLAG_CONDEXEC_MASK) >> ARM_TBFLAG_CONDEXEC_SHIFT)
#define ARM_TBFLAG_BSWAP_CODE(F) \
(((F) & ARM_TBFLAG_BSWAP_CODE_MASK) >> ARM_TBFLAG_BSWAP_CODE_SHIFT)
#define ARM_TBFLAG_SCTLR_B(F) \
(((F) & ARM_TBFLAG_SCTLR_B_MASK) >> ARM_TBFLAG_SCTLR_B_SHIFT)
#define ARM_TBFLAG_XSCALE_CPAR(F) \
(((F) & ARM_TBFLAG_XSCALE_CPAR_MASK) >> ARM_TBFLAG_XSCALE_CPAR_SHIFT)
#define ARM_TBFLAG_NS(F) \
(((F) & ARM_TBFLAG_NS_MASK) >> ARM_TBFLAG_NS_SHIFT)
static inline bool bswap_code(bool sctlr_b)
{
#ifdef CONFIG_USER_ONLY
/* BE8 (SCTLR.B = 0, TARGET_WORDS_BIGENDIAN = 1) is mixed endian.
* The invalid combination SCTLR.B=1/CPSR.E=1/TARGET_WORDS_BIGENDIAN=0
* would also end up as a mixed-endian mode with BE code, LE data.
*/
return
#ifdef TARGET_WORDS_BIGENDIAN
1 ^
#endif
sctlr_b;
#else
/* We do not implement BE32 mode for system-mode emulation, but
* anyway it would always do little-endian accesses with
* TARGET_WORDS_BIGENDIAN = 0.
*/
return 0;
#endif
}
/* Return the exception level to which FP-disabled exceptions should
* be taken, or 0 if FP is enabled.
*/
@ -2060,6 +2078,19 @@ static inline int fp_exception_el(CPUARMState *env)
return 0;
}
static inline bool arm_sctlr_b(CPUARMState *env)
{
return
/* We need not implement SCTLR.ITD in user-mode emulation, so
* let linux-user ignore the fact that it conflicts with SCTLR_B.
* This lets people run BE32 binaries with "-cpu any".
*/
#ifndef CONFIG_USER_ONLY
!arm_feature(env, ARM_FEATURE_V7) &&
#endif
(env->cp15.sctlr_el[1] & SCTLR_B) != 0;
}
static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
target_ulong *cs_base, int *flags)
{
@ -2072,7 +2103,7 @@ static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
| (env->vfp.vec_len << ARM_TBFLAG_VECLEN_SHIFT)
| (env->vfp.vec_stride << ARM_TBFLAG_VECSTRIDE_SHIFT)
| (env->condexec_bits << ARM_TBFLAG_CONDEXEC_SHIFT)
| (env->bswap_code << ARM_TBFLAG_BSWAP_CODE_SHIFT);
| (arm_sctlr_b(env) << ARM_TBFLAG_SCTLR_B_SHIFT);
if (!(access_secure_reg(env))) {
*flags |= ARM_TBFLAG_NS_MASK;
}

View file

@ -5094,7 +5094,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs)
#if 0
if (semihosting_enabled) {
int nr;
nr = arm_lduw_code(env, env->regs[15], env->bswap_code) & 0xff;
nr = arm_lduw_code(env, env->regs[15], arm_sctlr_b(env)) & 0xff;
if (nr == 0xab) {
env->regs[15] += 2;
qemu_log_mask(CPU_LOG_INT,
@ -5640,13 +5640,13 @@ static inline bool check_for_semihosting(CPUState *cs)
case EXCP_SWI:
/* Check for semihosting interrupt. */
if (env->thumb) {
imm = arm_lduw_code(env, env->regs[15] - 2, env->bswap_code)
imm = arm_lduw_code(env, env->regs[15] - 2, arm_sctlr_b(env))
& 0xff;
if (imm == 0xab) {
break;
}
} else {
imm = arm_ldl_code(env, env->regs[15] - 4, env->bswap_code)
imm = arm_ldl_code(env, env->regs[15] - 4, arm_sctlr_b(env))
& 0xffffff;
if (imm == 0x123456) {
break;
@ -5656,7 +5656,7 @@ static inline bool check_for_semihosting(CPUState *cs)
case EXCP_BKPT:
/* See if this is a semihosting syscall. */
if (env->thumb) {
imm = arm_lduw_code(env, env->regs[15], env->bswap_code)
imm = arm_lduw_code(env, env->regs[15], arm_sctlr_b(env))
& 0xff;
if (imm == 0xab) {
env->regs[15] += 2;

View file

@ -11175,7 +11175,7 @@ static void disas_a64_insn(CPUARMState *env, DisasContext *s)
return;
}
insn = arm_ldl_code(env, s->pc, s->bswap_code);
insn = arm_ldl_code(env, s->pc, s->sctlr_b);
s->insn = insn;
s->pc += 4;
@ -11250,11 +11250,7 @@ void gen_intermediate_code_a64(ARMCPU *cpu, TranslationBlock *tb)
dc->secure_routed_to_el3 = arm_feature(env, ARM_FEATURE_EL3) &&
!arm_el_is_aa64(env, 3);
dc->thumb = 0;
#if defined(TARGET_WORDS_BIGENDIAN)
dc->bswap_code = 1;
#else
dc->bswap_code = 0;
#endif
dc->sctlr_b = 0;
dc->condexec_mask = 0;
dc->condexec_cond = 0;
dc->mmu_idx = ARM_TBFLAG_MMUIDX(tb->flags);

View file

@ -7909,7 +7909,7 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn) // qq
if ((insn & 0x0ffffdff) == 0x01010000) {
ARCH(6);
/* setend */
if (((insn >> 9) & 1) != s->bswap_code) {
if (((insn >> 9) & 1) != bswap_code(s->sctlr_b)) {
/* Dynamic endianness switching not implemented. */
qemu_log_mask(LOG_UNIMP, "arm: unimplemented setend\n");
goto illegal_op;
@ -9427,7 +9427,7 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw
/* Fall through to 32-bit decode. */
}
insn = arm_lduw_code(env, s->pc, s->bswap_code);
insn = arm_lduw_code(env, s->pc, s->sctlr_b);
s->pc += 2;
insn |= (uint32_t)insn_hw1 << 16;
@ -10677,7 +10677,7 @@ static void disas_thumb_insn(CPUARMState *env, DisasContext *s) // qq
}
}
insn = arm_lduw_code(env, s->pc, s->bswap_code);
insn = arm_lduw_code(env, s->pc, s->sctlr_b);
// Unicorn: trace this instruction on request
if (HOOK_EXISTS_BOUNDED(s->uc, UC_HOOK_CODE, s->pc)) {
@ -11268,7 +11268,7 @@ static void disas_thumb_insn(CPUARMState *env, DisasContext *s) // qq
case 2:
/* setend */
ARCH(6);
if (((insn >> 3) & 1) != s->bswap_code) {
if (((insn >> 3) & 1) != bswap_code(s->sctlr_b)) {
/* Dynamic endianness switching not implemented. */
qemu_log_mask(LOG_UNIMP, "arm: unimplemented setend\n");
goto illegal_op;
@ -11423,7 +11423,7 @@ static bool insn_crosses_page(CPUARMState *env, DisasContext *s)
}
/* This must be a Thumb insn */
insn = arm_lduw_code(env, s->pc, s->bswap_code);
insn = arm_lduw_code(env, s->pc, s->sctlr_b);
if ((insn >> 11) >= 0x1d) {
/* Top five bits 0b11101 / 0b11110 / 0b11111 : this is the
@ -11481,7 +11481,7 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
dc->secure_routed_to_el3 = arm_feature(env, ARM_FEATURE_EL3) &&
!arm_el_is_aa64(env, 3);
dc->thumb = ARM_TBFLAG_THUMB(tb->flags); // qq
dc->bswap_code = ARM_TBFLAG_BSWAP_CODE(tb->flags);
dc->sctlr_b = ARM_TBFLAG_SCTLR_B(tb->flags);
dc->condexec_mask = (ARM_TBFLAG_CONDEXEC(tb->flags) & 0xf) << 1;
dc->condexec_cond = ARM_TBFLAG_CONDEXEC(tb->flags) >> 4;
dc->mmu_idx = ARM_TBFLAG_MMUIDX(tb->flags);
@ -11687,7 +11687,7 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
// imitate WFI instruction to halt emulation
dc->is_jmp = DISAS_WFI;
} else {
insn = arm_ldl_code(env, dc->pc, dc->bswap_code);
insn = arm_ldl_code(env, dc->pc, dc->sctlr_b);
dc->pc += 4;
disas_arm_insn(dc, insn);
}

View file

@ -16,7 +16,7 @@ typedef struct DisasContext {
struct TranslationBlock *tb;
int singlestep_enabled;
int thumb;
int bswap_code;
int sctlr_b;
#if !defined(CONFIG_USER_ONLY)
int user;
#endif