New patch to review for coreboot: a10ae8b libpayload: ARM: Keep track of the CPSR when exceptions happen.

[Marc Jones]

Marc Jones ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/7657

-gerrit

commit a10ae8bbfad9ca33ee4e3e60433f93806954fa3b
Author: Gabe Black 
Date:   Mon Dec 16 04:07:50 2013 -0800

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

Original-Change-Id: Id950fb09d72fb0f81e4eef2489c0849ce5dd8aca
    Original-Signed-off-by: Gabe Black 
    Original-Reviewed-on: https://chromium-review.googlesource.com/180253
    Original-Reviewed-by: Gabe Black 
    Original-Tested-by: Gabe Black 
    Original-Commit-Queue: Gabe Black 
    (cherry picked from commit 8e7014f24a580f84c91fa7b0369dfa922918adcc)
    Signed-off-by: Marc Jones

Change-Id: I49357fb6a65edeff7a9a48d54254308a6b0efdb7
---
 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 f0ce0ea..45b77a7 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 6a28c5c..974d172 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 13fda57..c6864a5 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));