coreboot t132: Stack init re-work

1) In order to avoid stack from overflowing during ramstage decompression,
initialize stack right at the beginning of romstage.
2) Declare different Kconfig options for stack at each stage.
3) Provide a macro that does stack seeding if required and calls appropriate
function.

BUG=None
BRANCH=None
TEST=Compiles and runs successfully on rush.

Original-Change-Id: I55d6ce59ea91affba3e86d68406921497c83fb52
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/206880
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
(cherry picked from commit 5e32d73803a2a9d222fcc4ca5f58efd3abe95d34)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Ib833a1badb170a33cbf20d232019425b59db60cd
Reviewed-on: http://review.coreboot.org/8583
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

1 files changed, 5 insertions, 36 deletions

diff --git a/src/soc/nvidia/tegra132/bootblock_asm.S b/src/soc/nvidia/tegra132/bootblock_asm.S
index ebd64a74258e..1b2fbb770903 100644
--- a/src/soc/nvidia/tegra132/bootblock_asm.S
+++ b/src/soc/nvidia/tegra132/bootblock_asm.S
@@ -31,6 +31,8 @@
 
 #include <arch/asm.h>
 
+#include "stack.S"
+
 ENTRY(_start)
 	/*
 	 * Set the cpu to System mode with IRQ and FIQ disabled. Prefetch/Data
@@ -40,40 +42,7 @@ ENTRY(_start)
 	 */
 	msr	cpsr_cxf, #0xdf
 
-	/*
-	 * Initialize the stack to a known value. This is used to check for
-	 * stack overflow later in the boot process.
-	 */
-	ldr	r0, .Stack
-	ldr	r1, .Stack_size
-	sub	r0, r0, r1
-	ldr	r1, .Stack
-	ldr	r2, =0xdeadbeef
-init_stack_loop:
-	str	r2, [r0]
-	add	r0, #4
-	cmp	r0, r1
-	bne	init_stack_loop
-
-/* Set stackpointer in internal RAM to call bootblock main() */
-call_bootblock:
-	ldr	sp, .Stack /* Set up stack pointer */
-	ldr	r0,=0x00000000
-	 /*
-	  * The current design of cpu_info places the
-	  * struct at the top of the stack. The number of
-	  * words pushed must be at least as large as that
-	  * struct.
-	  */
-	push	{r0-r2}
-	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
-	/*
-	 * Use "bl" instead of "b" even though we do not intend to return.
-	 * "bl" gets compiled to "blx" if we're transitioning from ARM to
-	 * Thumb. However, "b" will not and GCC may attempt to create a
-	 * wrapper which is currently broken.
-	 */
-	bl	main
+	stack_init stack=.Stack size=.Stack_size seed=1 func=main
 ENDPROC(_start)
 
 /* we do it this way because it's a 32-bit constant and
@@ -82,8 +51,8 @@ ENDPROC(_start)
  */
 .align 2
 .Stack:
-	.word CONFIG_STACK_TOP
+	.word CONFIG_BOOTBLOCK_STACK_TOP
 .align 2
 /* create this size the same way we do in ramstage.ld: top-bottom */
 .Stack_size:
-	.word CONFIG_STACK_TOP - CONFIG_STACK_BOTTOM
+	.word CONFIG_BOOTBLOCK_STACK_TOP - CONFIG_BOOTBLOCK_STACK_BOTTOM