callout.ah

Centrality Atlas II development software

/*
 * $QNXLicenseC:
 * Copyright 2001, 2008, QNX Software Systems. 
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"). You 
 * may not reproduce, modify or distribute this software except in 
 * compliance with the License. You may obtain a copy of the License 
 * at: http://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" basis, 
 * WITHOUT WARRANTIES OF ANY KIND, either express or implied.
 *
 * This file may contain contributions from others, either as 
 * contributors under the License or as licensors under other terms.  
 * Please review this entire file for other proprietary rights or license 
 * notices, as well as the QNX Development Suite License Guide at 
 * http://licensing.qnx.com/license-guide/ for other information.
 * $
 */

#include "asmoff.def"

	.text
	.align 2

#define	CALLOUT_START(rtn, rw_size, patcher)	\
	.globl	rtn;								\
	rtn:;										\
	.long	rw_size;							\
	.long	patcher;							\
	.long	end_##rtn - start_##rtn;			\
	start_##rtn:

#define	CALLOUT_END(rtn)	end_##rtn:

/*
 * Macro to patch callout code:
 *
 *	ptr			- name of register containing the address of the callout
 *	val			- name of register containing the value to patch
 *	t0, t1, t2	- names of registers to use as temporaries
 *
 * This code assumes the callout is written as follows:
 *
 *	callout_routine:
 *		mov	rX,     #0x000000ff
 *		orr rX, rX, #0x0000ff00
 *		orr rX, rX, #0x00ff0000
 *		orr rX, rX, #0xff000000
 *		:
 *		rest of routine
 *		:
 */
.macro	CALLOUT_PATCH	ptr, val, t0, t1, t2
	mov		&t0, #4
0:	and		&t1, &val, #0xff
	ldr		&t2, [&ptr]
	bic		&t2, &t2, #0xff
	orr		&t2, &t2, &t1
	str		&t2, [&ptr], #4
	mov		&val, &val, lsr #8
	subs	&t0, &t0, #1
	bne		0b
.endm