src/hermes/x86_main.asm
author Sam Lantinga <slouken@libsdl.org>
Tue, 01 Nov 2005 23:19:59 +0000
changeset 1166 da33b7e6d181
parent 0 74212992fb08
child 1199 2d6dc7de1145
permissions -rw-r--r--
Date: Tue, 1 Nov 2005 20:25:10 +0100 From: Dirk Mueller Subject: [PATCH] build SDL with nonexecutable stack libSDL is by default marked with an executable stack, which it doesn't actually need. the reason for this is that there are assembler files in the source tree not properly annotated with the "noexec stack" section. As such the linker does a safe-fallback and marks the whole lib as "requires executable stack". the patch below removes this by adding annotations. As far as I can see it shouldn't break anything.

;
; x86 format converters for HERMES
; Some routines Copyright (c) 1998 Christian Nentwich (brn@eleet.mcb.at)
; This source code is licensed under the GNU LGPL
; 
; Please refer to the file COPYING.LIB contained in the distribution for
; licensing conditions		
;
; Most routines are (c) Glenn Fiedler (ptc@gaffer.org), used with permission
; 

BITS 32

GLOBAL _ConvertX86
GLOBAL _x86return
	
GLOBAL _Hermes_X86_CPU

SECTION .note.GNU-stack noalloc progbits noexec nowrite
SECTION .data
	
cpu_flags dd 0
	
		
SECTION .text
		
;; _ConvertX86:	 
;; [ESP+8] ConverterInfo*
;; --------------------------------------------------------------------------
;; ConverterInfo (ebp+..)
;;   0:	void *s_pixels
;;   4:	int s_width
;;   8:	int s_height
;;  12:	int s_add
;;  16:	void *d_pixels
;;  20:	int d_width
;;  24:	int d_height
;;  28:	int d_add
;;  32:	void (*converter_function)() 
;;  36: int32 *lookup
	
_ConvertX86:
	push ebp
	mov ebp,esp

; Save the registers used by the blitters, necessary for optimized code
	pusha

	mov eax,[ebp+8]

        cmp dword [eax+4],BYTE 0
	je endconvert
	
	mov ebp,eax
	
	mov esi,[ebp+0]
	mov edi,[ebp+16]
	
y_loop:	
	mov ecx,[ebp+4]

	jmp [ebp+32]

_x86return:	
	add esi,[ebp+12]
	add edi,[ebp+28]
	
	dec dword  [ebp+8]
	jnz y_loop

; Restore the registers used by the blitters, necessary for optimized code
	popa
	
	pop ebp

endconvert:	
	ret		



;; Hermes_X86_CPU returns the CPUID flags in eax
	
_Hermes_X86_CPU:
	pushfd
	pop eax
	
	mov ecx,eax
	
	xor eax,040000h
	push eax
	
	popfd
	pushfd

	pop eax
	xor eax,ecx
	jz .L1			; Processor is 386

	push ecx
	popfd

	mov eax,ecx
	xor eax,200000h

	push eax
	popfd
	pushfd

	pop eax
	xor eax,ecx
	je .L1
	
	pusha
	
	mov eax,1
	cpuid

	mov [cpu_flags],edx

	popa

	mov eax,[cpu_flags]

.L1:	
	ret