diff options
| author | Michael Davidsaver <mdavidsaver@gmail.com> | 2017-01-27 15:20:24 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2017-01-27 15:29:08 +0000 |
| commit | dc7abe4d65ad39390b2db120f5ad18f8f6576f8b (patch) | |
| tree | 8cf0e2eecbbc978983485a362b45d55ad815cdec /target | |
| parent | bdd04fc76a78d61ae0f0e93ce345f9cf2e49a9a8 (diff) | |
armv7m: FAULTMASK should be 0 on reset
For M profile CPUs, FAULTMASK should be 0 on reset, like PRIMASK.
QEMU stores FAULTMASK in the PSTATE F bit, so (as with PRIMASK in the
I bit) we have to clear these to undo the A profile default of 1.
Update the comment accordingly and move it so that it's closer to the
code it's referring to.
Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1485285380-10565-10-git-send-email-peter.maydell@linaro.org
[PMM: rewrote commit message, moved comments]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target')
| -rw-r--r-- | target/arm/cpu.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/target/arm/cpu.c b/target/arm/cpu.c index c804f59993..0814f73462 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -179,15 +179,16 @@ static void arm_cpu_reset(CPUState *s) /* SVC mode with interrupts disabled. */ env->uncached_cpsr = ARM_CPU_MODE_SVC; env->daif = PSTATE_D | PSTATE_A | PSTATE_I | PSTATE_F; - /* On ARMv7-M the CPSR_I is the value of the PRIMASK register, and is - * clear at reset. Initial SP and PC are loaded from ROM. - */ + if (arm_feature(env, ARM_FEATURE_M)) { uint32_t initial_msp; /* Loaded from 0x0 */ uint32_t initial_pc; /* Loaded from 0x4 */ uint8_t *rom; - env->daif &= ~PSTATE_I; + /* For M profile we store FAULTMASK and PRIMASK in the + * PSTATE F and I bits; these are both clear at reset. + */ + env->daif &= ~(PSTATE_I | PSTATE_F); /* The reset value of this bit is IMPDEF, but ARM recommends * that it resets to 1, so QEMU always does that rather than making @@ -195,6 +196,7 @@ static void arm_cpu_reset(CPUState *s) */ env->v7m.ccr = R_V7M_CCR_STKALIGN_MASK; + /* Load the initial SP and PC from the vector table at address 0 */ rom = rom_ptr(0); if (rom) { /* Address zero is covered by ROM which hasn't yet been |