aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorPeter Maydell <peter.maydell@linaro.org>2015-11-27 09:09:14 -0500
committerPeter Maydell <peter.maydell@linaro.org>2017-01-24 19:13:46 +0000
commit026dd3cb92f523b2256264750deb47cb767f02ac (patch)
tree65e9dabbc2efa0bec9b3076b68c5334cf7566d71
parentea812d47d3e5de812badb0acfd3185e40d56777c (diff)
downloadqemu-arm-m-profile-fixes.tar.gz
armv7m: R14 should reset to 0xffffffffm-profile-fixes
For M profile (unlike A profile) the reset value of R14 is specified as 0xffffffff. (The rationale is that this is an illegal exception return value, so if guest code tries to return to it it will result in a helpful exception.) Registers r0 to r12 and the flags are architecturally UNKNOWN on reset, so we leave those at zero. Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--target/arm/cpu.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 0814f73462..e9f10f7747 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -196,6 +196,9 @@ static void arm_cpu_reset(CPUState *s)
*/
env->v7m.ccr = R_V7M_CCR_STKALIGN_MASK;
+ /* Unlike A/R profile, M profile defines the reset LR value */
+ env->regs[14] = 0xffffffff;
+
/* Load the initial SP and PC from the vector table at address 0 */
rom = rom_ptr(0);
if (rom) {