From 70810935313bfb073c942f9a96bdd8502a05f6c1 Mon Sep 17 00:00:00 2001
From: Juergen Beisert <jbe@pengutronix.de>
Date: Tue, 12 Jan 2010 11:15:47 +0100
Subject: Add a special command to load and start a bzImage on x86

Other architectures are supporting the uImage format used by barebox's 'bootm'
command. x86 does'nt. So, we need a special command to be able to boot the
x86 specific bzImage format.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/x86/include/asm/syslib.h |  4 +++
 arch/x86/lib/Makefile         |  1 +
 arch/x86/lib/linux_start.S    | 75 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)
 create mode 100644 arch/x86/lib/linux_start.S

(limited to 'arch')

diff --git a/arch/x86/include/asm/syslib.h b/arch/x86/include/asm/syslib.h
index a1316872c4..eebe1a99c9 100644
--- a/arch/x86/include/asm/syslib.h
+++ b/arch/x86/include/asm/syslib.h
@@ -27,3 +27,7 @@ extern int bios_disk_rw_int13_extensions(int, int, void*) __attribute__((regparm
 extern uint16_t bios_get_memsize(void);
 
 #endif
+
+#ifdef CONFIG_CMD_LINUX16
+extern void bios_start_linux(unsigned) __attribute__((regparm(1)));
+#endif
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 013d369eaa..b67629f115 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -6,3 +6,4 @@ obj-y += gdt.o
 obj-$(CONFIG_X86_BIOS_BRINGUP) += memory16.o
 obj-$(CONFIG_X86_BIOS_BRINGUP) += traveler.o
 obj-$(CONFIG_X86_BIOS_BRINGUP) += bios_disk.o
+obj-$(CONFIG_CMD_LINUX16) += linux_start.o
diff --git a/arch/x86/lib/linux_start.S b/arch/x86/lib/linux_start.S
new file mode 100644
index 0000000000..fac2510d1c
--- /dev/null
+++ b/arch/x86/lib/linux_start.S
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2009 Juergen Beisert, Pengutronix
+ *
+ * Mostly stolen from the GRUB2 project
+ *  Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007,2008  Free Software Foundation, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+/**
+ * @file
+ * @brief Start the Linux real mode setup code
+ *
+ * Note: These functions are running in flat and real mode. Due to some
+ * other restrictions these routines must running from an address
+ * space below 0x10000
+ */
+
+/*
+ *   void bios_start_linux(unsigned segment)
+ *
+ */
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
+
+	.section .boot.text.bios_start_linux, "ax"
+	.code32
+	.globl bios_start_linux
+	.type bios_start_linux, @function
+
+	.extern prot_to_real
+
+bios_start_linux:
+	/* 'prot_to_real' eats our eax content */
+	movl %eax, %ebx
+	addl $0x20, %eax
+	movw %ax, setup_seg
+
+	call prot_to_real
+
+	.code16
+
+	cli
+	/* all segment registers are using the same segment */
+	movw %bx, %ss
+	movw %bx, %ds
+	movw %bx, %es
+	movw %bx, %fs
+	movw %bx, %gs
+
+	/* stack for the setup code (end of heap) */
+	movw $0x9000, %sp
+
+	/* do an 'ljmp' and never return */
+	.byte	0xea
+	.word	0
+setup_seg:
+	.word	0
+
+	.code32
+
+#endif
-- 
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