From d385ed29b94af71dedeb5f44d72ad8dab43c4664 Mon Sep 17 00:00:00 2001
From: Patrick Georgi <patrick.georgi@coresystems.de>
Date: Thu, 21 May 2009 10:02:52 +0000
Subject: This change adds PPC support to libpayload, and hooks it up in the
 build process. The PPC support is still stubbed, with commented out x86 code
 as guide line for an implementor.

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4293 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
---
 payloads/libpayload/arch/i386/head.S | 97 ++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 payloads/libpayload/arch/i386/head.S

(limited to 'payloads/libpayload/arch/i386/head.S')

diff --git a/payloads/libpayload/arch/i386/head.S b/payloads/libpayload/arch/i386/head.S
new file mode 100644
index 0000000000..db18a5195f
--- /dev/null
+++ b/payloads/libpayload/arch/i386/head.S
@@ -0,0 +1,97 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2008 Advanced Micro Devices, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+	.code32
+	.global _entry, _leave
+	.text
+	.align 4
+
+/*
+ * Our entry point - assume that the CPU is in 32 bit protected mode and
+ * all segments are in a flat model. That's our operating mode, so we won't
+ * change anything.
+ */
+_entry:
+	call _init
+
+	/* We're back - go back to the bootloader. */
+	ret
+
+	.align 4
+
+#define MB_MAGIC 0x1BADB002
+#define MB_FLAGS 0x00010003
+
+mb_header:
+	.long MB_MAGIC
+	.long MB_FLAGS
+	.long -(MB_MAGIC + MB_FLAGS)
+	.long mb_header
+	.long _start
+	.long _edata
+	.long _end
+	.long _init
+
+/*
+ * This function saves off the previous stack and switches us to our
+ * own execution environment.
+ */
+_init:
+	/* No interrupts, please. */
+	cli
+
+	/* Store current stack pointer. */
+	movl %esp, %esi
+
+	/* Store EAX and EBX */
+
+	movl %eax,loader_eax
+	movl %ebx,loader_ebx
+
+	/* Setup new stack. */
+	movl $_stack, %ebx
+
+	movl %ebx, %esp
+
+	/* Save old stack pointer. */
+	pushl %esi
+
+	/* Let's rock. */
+	call start_main
+
+	/* %eax has the return value - pass it on unmolested */
+_leave:
+	/* Get old stack pointer. */
+	popl %ebx
+
+	/* Restore old stack. */
+	movl %ebx, %esp
+
+	/* Return to the original context. */
+	ret
-- 
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