2 files changed, 58 insertions, 0 deletions
diff --git a/roms/ipxe/src/arch/x86_64/core/linux/linux_syscall.S b/roms/ipxe/src/arch/x86_64/core/linux/linux_syscall.S
new file mode 100644
index 00000000..d2805f94
--- /dev/null
+++ b/roms/ipxe/src/arch/x86_64/core/linux/linux_syscall.S
@@ -0,0 +1,33 @@
+
+	.section ".data"
+	.globl linux_errno
+
+linux_errno:	.int 0
+
+	.section ".text"
+	.code64
+	.globl linux_syscall
+	.type  linux_syscall, @function
+
+linux_syscall:
+	movq	%rdi, %rax    // C arg1 -> syscall number
+	movq	%rsi, %rdi    // C arg2 -> syscall arg1
+	movq	%rdx, %rsi    // C arg3 -> syscall arg2
+	movq	%rcx, %rdx    // C arg4 -> syscall arg3
+	movq	%r8, %r10     // C arg5 -> syscall arg4
+	movq	%r9, %r8      // C arg6 -> syscall arg5
+	movq	8(%rsp), %r9  // C arg7 -> syscall arg6
+
+	syscall
+
+	cmpq	$-4095, %rax
+	jae	1f
+	ret
+
+1:
+	negq	%rax
+	movl	%eax, linux_errno
+	movq	$-1, %rax
+	ret
+
+	.size linux_syscall, . - linux_syscall
diff --git a/roms/ipxe/src/arch/x86_64/core/linux/linuxprefix.S b/roms/ipxe/src/arch/x86_64/core/linux/linuxprefix.S
new file mode 100644
index 00000000..ec8a9dec
--- /dev/null
+++ b/roms/ipxe/src/arch/x86_64/core/linux/linuxprefix.S
@@ -0,0 +1,25 @@
+#include <linux/unistd.h>
+
+	.section ".text"
+	.code64
+	.globl _linux_start
+	.type _linux_start, @function
+
+_linux_start:
+	xorq	%rbp, %rbp
+
+	popq	%rdi       // argc -> C arg1
+	movq	%rsp, %rsi // argv -> C arg2
+
+	andq	$~15, %rsp // 16-byte align the stack
+
+	call	save_args
+
+	/* Our main doesn't use any arguments */
+	call	main
+
+	movq	%rax, %rdi // rc -> syscall arg1
+	movq	$__NR_exit, %rax
+	syscall
+
+	.size _linux_start, . - _linux_start