From dfc22e29ec2f687375d32c9f7662416d0c9f97d3 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Thu, 7 Mar 2013 19:57:10 -0800
Subject: [PATCH] runtime: change 386 startup convention

Now the default startup is that the program begins at _rt0_386_$GOOS,
which behaves as if calling main(argc, argv). Main jumps to _rt0_386.

This makes the _rt0_386 entry match the expected semantics for
the standard C "main" function, which we can now provide for use when
linking against a standard C library.

386 analogue of https://golang.org/cl/7525043

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/7551045
---
 src/pkg/runtime/asm_386.s          |  4 ++--
 src/pkg/runtime/rt0_darwin_386.s   | 10 ++++++++--
 src/pkg/runtime/rt0_freebsd_386.s  | 11 ++++++++---
 src/pkg/runtime/rt0_linux_386.s    | 14 ++++++++++----
 src/pkg/runtime/rt0_netbsd_386.s   | 12 ++++++++++--
 src/pkg/runtime/rt0_openbsd_386.s  | 12 ++++++++++--
 src/pkg/runtime/rt0_plan9_386.s    |  7 +++++++
 src/pkg/runtime/rt0_windows_386.s  | 11 ++++++++++-
 src/pkg/runtime/signal_linux_386.c |  3 +--
 9 files changed, 66 insertions(+), 18 deletions(-)

diff --git a/src/pkg/runtime/asm_386.s b/src/pkg/runtime/asm_386.s
index 96f04e0ae90..375274e0b3a 100644
--- a/src/pkg/runtime/asm_386.s
+++ b/src/pkg/runtime/asm_386.s
@@ -6,8 +6,8 @@
 
 TEXT _rt0_386(SB),7,$0
 	// copy arguments forward on an even stack
-	MOVL	0(SP), AX		// argc
-	LEAL	4(SP), BX		// argv
+	MOVL	argc+0(FP), AX
+	MOVL	argv+4(FP), BX
 	SUBL	$128, SP		// plenty of scratch
 	ANDL	$~15, SP
 	MOVL	AX, 120(SP)		// save argc, argv away
diff --git a/src/pkg/runtime/rt0_darwin_386.s b/src/pkg/runtime/rt0_darwin_386.s
index 30b497f5e74..4b4c1f29422 100644
--- a/src/pkg/runtime/rt0_darwin_386.s
+++ b/src/pkg/runtime/rt0_darwin_386.s
@@ -2,7 +2,13 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Darwin and Linux use the same linkage to main
+TEXT _rt0_386_darwin(SB),7,$8
+	MOVL	8(SP), AX
+	LEAL	12(SP), BX
+	MOVL	AX, 0(SP)
+	MOVL	BX, 4(SP)
+	CALL	main(SB)
+	INT	$3
 
-TEXT _rt0_386_darwin(SB),7,$0
+TEXT main(SB),7,$0
 	JMP	_rt0_386(SB)
diff --git a/src/pkg/runtime/rt0_freebsd_386.s b/src/pkg/runtime/rt0_freebsd_386.s
index 3ca981b3a31..c84482cdbfe 100644
--- a/src/pkg/runtime/rt0_freebsd_386.s
+++ b/src/pkg/runtime/rt0_freebsd_386.s
@@ -2,8 +2,13 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Darwin and Linux use the same linkage to main
+TEXT _rt0_386_freebsd(SB),7,$8
+	MOVL	8(SP), AX
+	LEAL	12(SP), BX
+	MOVL	AX, 0(SP)
+	MOVL	BX, 4(SP)
+	CALL	main(SB)
+	INT	$3
 
-TEXT _rt0_386_freebsd(SB),7,$0
+TEXT main(SB),7,$0
 	JMP	_rt0_386(SB)
-
diff --git a/src/pkg/runtime/rt0_linux_386.s b/src/pkg/runtime/rt0_linux_386.s
index 83149540ec4..73cca5d9805 100644
--- a/src/pkg/runtime/rt0_linux_386.s
+++ b/src/pkg/runtime/rt0_linux_386.s
@@ -2,11 +2,17 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Darwin and Linux use the same linkage to main
-
-TEXT _rt0_386_linux(SB),7,$0
+TEXT _rt0_386_linux(SB),7,$8
+	MOVL	8(SP), AX
+	LEAL	12(SP), BX
+	MOVL	AX, 0(SP)
+	MOVL	BX, 4(SP)
 	CALL	runtime·linux_setup_vdso(SB)
-	JMP		_rt0_386(SB)
+	CALL	main(SB)
+	INT	$3
+
+TEXT main(SB),7,$0
+	JMP	_rt0_386(SB)
 
 TEXT _fallback_vdso(SB),7,$0
 	INT	$0x80
diff --git a/src/pkg/runtime/rt0_netbsd_386.s b/src/pkg/runtime/rt0_netbsd_386.s
index 829e4133b8b..b4c029c538d 100644
--- a/src/pkg/runtime/rt0_netbsd_386.s
+++ b/src/pkg/runtime/rt0_netbsd_386.s
@@ -2,5 +2,13 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-TEXT _rt0_386_netbsd(SB),7,$0
-	JMP     _rt0_386(SB)
+TEXT _rt0_386_netbsd(SB),7,$8
+	MOVL	8(SP), AX
+	LEAL	12(SP), BX
+	MOVL	AX, 0(SP)
+	MOVL	BX, 4(SP)
+	CALL	main(SB)
+	INT	$3
+
+TEXT main(SB),7,$0
+	JMP	_rt0_386(SB)
diff --git a/src/pkg/runtime/rt0_openbsd_386.s b/src/pkg/runtime/rt0_openbsd_386.s
index e7e0da78f2f..9c00a733408 100644
--- a/src/pkg/runtime/rt0_openbsd_386.s
+++ b/src/pkg/runtime/rt0_openbsd_386.s
@@ -2,5 +2,13 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-TEXT _rt0_386_openbsd(SB),7,$0
-	JMP     _rt0_386(SB)
+TEXT _rt0_386_openbsd(SB),7,$8
+	MOVL	8(SP), AX
+	LEAL	12(SP), BX
+	MOVL	AX, 0(SP)
+	MOVL	BX, 4(SP)
+	CALL	main(SB)
+	INT	$3
+
+TEXT main(SB),7,$0
+	JMP	_rt0_386(SB)
diff --git a/src/pkg/runtime/rt0_plan9_386.s b/src/pkg/runtime/rt0_plan9_386.s
index 56f3a0f6c72..7af1eae7cb9 100644
--- a/src/pkg/runtime/rt0_plan9_386.s
+++ b/src/pkg/runtime/rt0_plan9_386.s
@@ -26,6 +26,13 @@ argv_fix:
 	LOOP	argv_fix
 	
 	CALL	runtime·asminit(SB)
+
+	MOVL	0(SP), AX
+	LEAL	4(SP), BX
+	PUSHL	BX
+	PUSHL	AX
+	PUSHL	$-1
+
 	JMP	_rt0_386(SB)
 
 DATA  runtime·isplan9(SB)/4, $1
diff --git a/src/pkg/runtime/rt0_windows_386.s b/src/pkg/runtime/rt0_windows_386.s
index a06aa787e2e..6e34c6c172a 100644
--- a/src/pkg/runtime/rt0_windows_386.s
+++ b/src/pkg/runtime/rt0_windows_386.s
@@ -2,8 +2,17 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-TEXT _rt0_386_windows(SB),7,$0
+TEXT _rt0_386_windows(SB),7,$12
+	MOVL	12(SP), AX
+	LEAL	16(SP), BX
+	MOVL	AX, 4(SP)
+	MOVL	BX, 8(SP)
+	MOVL	$-1, 0(SP) // return PC for main
+	JMP	main(SB)
+
+TEXT main(SB),7,$0
 	JMP	_rt0_386(SB)
 
+
 DATA  runtime·iswindows(SB)/4, $1
 GLOBL runtime·iswindows(SB), $4
diff --git a/src/pkg/runtime/signal_linux_386.c b/src/pkg/runtime/signal_linux_386.c
index 9b45ec3bd2e..ed9ae3a8e54 100644
--- a/src/pkg/runtime/signal_linux_386.c
+++ b/src/pkg/runtime/signal_linux_386.c
@@ -155,9 +155,8 @@ extern uint32 runtime·_vdso;
 
 #pragma textflag 7
 void
-runtime·linux_setup_vdso(int32 argc, void *argv_list)
+runtime·linux_setup_vdso(int32 argc, byte **argv)
 {
-	byte **argv = &argv_list;
 	byte **envp;
 	uint32 *auxv;