From bb5b66b8878d48c505fe1a653d5a59e21d3d9380 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Jaroszy=C5=84ski?= <p.jaroszynski@gmail.com>
Date: Wed, 9 Jun 2010 19:55:09 +0200
Subject: [PATCH] [linux] Add linuxprefix
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Add a minimal _start required to run main.

Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/arch/i386/prefix/linuxprefix.S   | 25 +++++++++++++++++++++++++
 src/arch/x86_64/prefix/linuxprefix.S | 22 ++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 src/arch/i386/prefix/linuxprefix.S
 create mode 100644 src/arch/x86_64/prefix/linuxprefix.S

diff --git a/src/arch/i386/prefix/linuxprefix.S b/src/arch/i386/prefix/linuxprefix.S
new file mode 100644
index 00000000..881c61df
--- /dev/null
+++ b/src/arch/i386/prefix/linuxprefix.S
@@ -0,0 +1,25 @@
+#include <linux/unistd.h>
+
+	.section ".text"
+	.code32
+	.globl _start
+	.type _start, @function
+
+_start:
+	xorl	%ebp, %ebp
+
+	popl	%esi       // save argc
+	movl	%esp, %edi // save argv
+
+	andl	$~15, %esp // 16-byte align the stack
+
+	pushl	%edi // argv -> C arg2
+	pushl	%esi // argc -> C arg1
+
+	call	main
+
+	movl	%eax, %ebx // rc -> syscall arg1
+	movl	$__NR_exit, %eax
+	int	$0x80
+
+	.size _start, . - _start
diff --git a/src/arch/x86_64/prefix/linuxprefix.S b/src/arch/x86_64/prefix/linuxprefix.S
new file mode 100644
index 00000000..20163b8a
--- /dev/null
+++ b/src/arch/x86_64/prefix/linuxprefix.S
@@ -0,0 +1,22 @@
+#include <linux/unistd.h>
+
+	.section ".text"
+	.code64
+	.globl _start
+	.type _start, @function
+
+_start:
+	xorq	%rbp, %rbp
+
+	popq	%rdi       // argc -> C arg1
+	movq	%rsp, %rsi // argv -> C arg2
+
+	andq	$~15, %rsp // 16-byte align the stack
+
+	call	main
+
+	movq	%rax, %rdi // rc -> syscall arg1
+	movq	$__NR_exit, %rax
+	syscall
+
+	.size _start, . - _start