From: Graeme Russ <graeme.russ@gmail.com>
Date: Tue, 8 Nov 2011 02:33:19 +0000 (+0000)
Subject: x86: Add multiboot header
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=a206cc23431474a9890f0301f02f50ad3dc9b062;p=u-boot.git

x86: Add multiboot header

By adding a multiboot header, U-Boot can be loaded by GRUB2. Using GRUB2 to
bootstrap U-Boot is useful for using an existing BIOS to get an initial
U-Boot port up and running before implementing the low-level reset vector
code, SDRAM init, etc. and overwriting the BIOS

Signed-off-by: Graeme Russ <graeme.russ@gmail.com>
---

diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S
index 5adb3874b4..d099fc9ba3 100644
--- a/arch/x86/cpu/start.S
+++ b/arch/x86/cpu/start.S
@@ -129,3 +129,23 @@ die:	hlt
 blank_idt_ptr:
 	.word	0		/* limit */
 	.long	0		/* base */
+
+	.p2align	2	/* force 4-byte alignment */
+
+multiboot_header:
+	/* magic */
+	.long	0x1BADB002
+	/* flags */
+	.long	(1 << 16)
+	/* checksum */
+	.long	-0x1BADB002 - (1 << 16)
+	/* header addr */
+	.long	multiboot_header - _x86boot_start + CONFIG_SYS_TEXT_BASE
+	/* load addr */
+	.long	CONFIG_SYS_TEXT_BASE
+	/* load end addr */
+	.long	0
+	/* bss end addr */
+	.long	0
+	/* entry addr */
+	.long	CONFIG_SYS_TEXT_BASE