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[U-Boot,02/20] x86: Reorder x86's post relocation memory layout

Message ID 1351978902-23719-3-git-send-email-sjg@chromium.org
State Accepted, archived
Delegated to: Simon Glass
Headers show

Commit Message

Simon Glass Nov. 3, 2012, 9:41 p.m. UTC 
From: Gabe Black <gabeblack@chromium.org>

This changes the layout in decreasing addresses from:

1. Stack
2. Sections in the image
3. Heap

to

1. Sections in the image
2. Heap
3. Stack

This allows the stack to grow significantly more since it isn't constrained by
the other u-boot areas. More importantly, the generic memory wipe code assumes
that the stack is the lowest addressed area used by the main part of u-boot.
In the original layout, that means that u-boot tramples all over itself. In
the new layout, it works.

Signed-off-by: Gabe Black <gabeblack@google.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
---
 arch/x86/lib/init_helpers.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)
diff mbox

Patch

diff --git a/arch/x86/lib/init_helpers.c b/arch/x86/lib/init_helpers.c
index 4a6d9f3..6032ee5 100644
--- a/arch/x86/lib/init_helpers.c
+++ b/arch/x86/lib/init_helpers.c
@@ -96,16 +96,15 @@  int calculate_relocation_address(void)
 	dest_addr &= ~15;
 	gd->gdt_addr = dest_addr;
 
-	/* Stack is below GDT */
-	gd->start_addr_sp = dest_addr;
-
-	/* U-Boot is below the stack */
-	dest_addr -= CONFIG_SYS_STACK_SIZE;
+	/* U-Boot is below Global Data */
 	dest_addr -= (bss_end - text_start);
 	dest_addr &= ~15;
 	gd->relocaddr = dest_addr;
 	gd->reloc_off = (dest_addr - text_start);
 
+	/* Stack is at the bottom, so it can grow down */
+	gd->start_addr_sp = dest_addr - CONFIG_SYS_MALLOC_LEN;
+
 	return 0;
 }