[gPXE-devel] [PATCH 04/33] [linux] Add linuxprefix

[Piotr Jaroszyński]

Add a minimal _start required to run main.

Signed-off-by: Piotr Jaroszyński <p.jaroszynski at gmail.com>
---
 src/arch/i386/prefix/linuxprefix.S   |   25 +++++++++++++++++++++++++
 src/arch/x86_64/prefix/linuxprefix.S |   22 ++++++++++++++++++++++
 2 files changed, 47 insertions(+), 0 deletions(-)
 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 0000000..881c61d
--- /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 0000000..20163b8
--- /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
-- 
1.7.1