From 8e7014f24a580f84c91fa7b0369dfa922918adcc Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Mon, 16 Dec 2013 04:07:50 -0800 Subject: [PATCH] libpayload: ARM: Keep track of the CPSR when exceptions happen. Use the SPSR to extract and inject CPSR values when an exception happens and pass that information to exception hooks. The register structure GDB expects when using its remote protocol has a spot for the CPSR. BUG=None TEST=Built and booted on link, nyan. BRANCH=None Change-Id: Id950fb09d72fb0f81e4eef2489c0849ce5dd8aca Signed-off-by: Gabe Black Reviewed-on: https://chromium-review.googlesource.com/180253 Reviewed-by: Gabe Black Tested-by: Gabe Black Commit-Queue: Gabe Black --- payloads/libpayload/arch/arm/exception.c | 7 ++++--- payloads/libpayload/arch/arm/exception_asm.S | 4 ++++ payloads/libpayload/include/arm/arch/exception.h | 1 + 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/payloads/libpayload/arch/arm/exception.c b/payloads/libpayload/arch/arm/exception.c index f0ce0ea8c3..45b77a7460 100644 --- a/payloads/libpayload/arch/arm/exception.c +++ b/payloads/libpayload/arch/arm/exception.c @@ -66,7 +66,7 @@ static void dump_stack(uintptr_t addr, size_t bytes) } } -static void print_regs(uint32_t *regs) +static void print_regs(struct exception_state *state) { int i; @@ -81,8 +81,9 @@ static void print_regs(uint32_t *regs) printf("IP"); else printf("R%d", i); - printf(" = 0x%08x\n", regs[i]); + printf(" = 0x%08x\n", state->regs[i]); } + printf("CPSR = 0x%08x\n", state->cpsr); } void exception_dispatch(struct exception_state *state, int idx); @@ -102,7 +103,7 @@ void exception_dispatch(struct exception_state *state, int idx) else printf("exception _not_used.\n"); } - print_regs(state->regs); + print_regs(state); dump_stack(state->regs[13], 512); halt(); } diff --git a/payloads/libpayload/arch/arm/exception_asm.S b/payloads/libpayload/arch/arm/exception_asm.S index 6a28c5cdef..974d1724b5 100644 --- a/payloads/libpayload/arch/arm/exception_asm.S +++ b/payloads/libpayload/arch/arm/exception_asm.S @@ -74,9 +74,13 @@ exception_common: stmfd sp, { sp, lr }^ sub sp, sp, $8 push { r0 - r12 } + mrs r0, SPSR + push { r0 } mov r0, sp ldr r1, exception_idx blx exception_dispatch + pop { r0 } + msr SPSR_cxsf, r0 pop { r0 - r12 } add sp, sp, $8 ldmfd sp!, { pc }^ diff --git a/payloads/libpayload/include/arm/arch/exception.h b/payloads/libpayload/include/arm/arch/exception.h index 13fda57aa7..c6864a5ad2 100644 --- a/payloads/libpayload/include/arm/arch/exception.h +++ b/payloads/libpayload/include/arm/arch/exception.h @@ -36,6 +36,7 @@ void set_vbar(uint32_t vbar); struct exception_state { + uint32_t cpsr; uint32_t regs[16]; } __attribute__((packed));