www.pudn.com > usbboot-v1.2.rar.zip > head.S, change:2008-02-27,size:1228b

/*
 * head.S
 *
 * Entry point of the firmware.
 * The firmware code are executed in the ICache.
 *
 * Copyright (C) 2006 Ingenic Semiconductor Inc.
 *
 */

	.text
	.extern c_main
	
	.globl _start
	.set noreorder
_start:
	//----------------------------------------------------
	// display LED for debug
	//----------------------------------------------------
//	la	$9, 0xb6000058		// LED address
//	la	$8, led_display_data
//	li	$7, 8
//_led_display:
//	lb	$6, 0($8)
//	sb	$6, 0($9)
//	sub	$7, $7, 1
//	addi	$8, $8, 1
//	bgtz	$7, _led_display
//	addi	$9, $9, 1

	//----------------------------------------------------
	// Init CP0 registers
	//----------------------------------------------------
	mtc0	$0, $18			// CP0_WATCHLO
	mtc0	$0, $19			// CP0_WATCHHI

	li	$8, 0x0040FC04
	mtc0	$8, $12			// CP0_STATUS

	li	$9, 0x00800000		// IV=1, clear cause
	mtc0	$9, $13			// CP0_CAUSE


	//----------------------------------------------------
	// setup stack, jump to C code
	//----------------------------------------------------
	la	$29, 0x80002000		// sp
	la	$0, c_main
	j	c_main
	nop

/*
	.align	2
led_display_data:
	.byte	0x4a
	.byte	0x5a
	.byte	0x34
	.byte	0x37
	.byte	0x34
	.byte	0x30
	.byte	0x56
	.byte	0x31
*/
	.set reorder