[coreboot-gerrit] New patch to review for coreboot: 188f6ee arm64: move seeding stack to C

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9014

-gerrit

commit 188f6ee21705e595fae03f6571fc8867c5c95e89
Author: Aaron Durbin <adurbin at chromium.org>
Date:   Wed Aug 27 15:30:56 2014 -0500

    arm64: move seeding stack to C
    
    Move the stack seeding out of assembly and into C so the
    code in stage_entry.S can more easily be used. The seeding
    of the stack doesn't touch at least 256 bytes to account
    for current usage at time fo the call.
    
    BUG=chrome-os-partner:31545
    BRANCH=None
    TEST=Built and booted into kernel on ryu.
    
    Change-Id: Ib9659ec4265652461bde746140567f21533cc265
    Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
    Original-Commit-Id: f478cfe175aa674cdfdbbd890663eeaad9d82b1f
    Original-Change-Id: I44004220a02b1ff06d27a0555eb4e96d9e213544
    Original-Signed-off-by: Aaron Durbin <adurbin at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/214770
    Original-Reviewed-by: Furquan Shaikh <furquan at chromium.org>
---
 src/arch/arm64/c_entry.c     | 20 ++++++++++++++++++++
 src/arch/arm64/stage_entry.S | 26 +-------------------------
 2 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/src/arch/arm64/c_entry.c b/src/arch/arm64/c_entry.c
index a4d4b0c..f08a585 100644
--- a/src/arch/arm64/c_entry.c
+++ b/src/arch/arm64/c_entry.c
@@ -18,14 +18,34 @@
  */
 
 #include <arch/stages.h>
+#include <arch/cpu.h>
 
 void __attribute__((weak)) arm64_soc_init(void)
 {
 	/* Default weak implementation does nothing. */
 }
 
+static void seed_stack(void)
+{
+	char *stack_begin;
+	uint64_t *slot;
+	int i;
+	int size;
+
+	stack_begin = cpu_get_stack(smp_processor_id());
+	stack_begin -= CONFIG_STACK_SIZE;
+	slot = (void *)stack_begin;
+
+	/* Pad out 256 bytes for current usage. */
+	size = CONFIG_STACK_SIZE - 256;
+	size /= sizeof(*slot);
+	for (i = 0; i < size; i++)
+		*slot++ = 0xdeadbeefdeadbeefULL;
+}
+
 void arm64_init(void)
 {
+	seed_stack();
 	arm64_soc_init();
 	main();
 }
diff --git a/src/arch/arm64/stage_entry.S b/src/arch/arm64/stage_entry.S
index 1de8894..8613655 100644
--- a/src/arch/arm64/stage_entry.S
+++ b/src/arch/arm64/stage_entry.S
@@ -74,30 +74,6 @@ ENTRY(cpu_get_exception_stack)
 	.quad	_estack_exceptions
 ENDPROC(cpu_get_exception_stack)
 
-
-ENTRY(seed_stack)
-	/*
-	 * Initialize the stack to a known value. This is used to check for
-	 * stack overflow later in the boot process.
-	 */
-	ldr	x0, .stack_bottom
-	mov	x1, sp
-	ldr	x2, =0xdeadbeefdeadbeef
-	ldr	x3, =0x8
-
-init_stack_loop:
-	str	x2, [x0]
-	add	x0, x0, x3
-	cmp	x0, x1
-	bne	init_stack_loop
-
-load_stack:
-	b	arm64_init
-	.align	4
-	.stack_bottom:
-		.quad _stack
-ENDPROC(seed_stack)
-
 /*
  * Boot strap the processor into a C environemnt. That consists of providing
  * 16-byte aligned stack. The programming enviroment uses SP_EL0 as its main
@@ -123,7 +99,7 @@ ENTRY(arm64_c_environment)
 	bl	cpu_get_stack
 	mov	sp, x0
 
-	b	seed_stack
+	b	arm64_init
 ENDPROC(arm64_c_environment)
 
 CPU_RESET_ENTRY(arm64_cpu_startup)