head.s

嵌入式系统设计与实例开发源码

/*
 * arch/alpha/boot/head.S
 *
 * initial bootloader stuff..
 */

#include <asm/system.h>

	.set noreorder
	.globl	__start
	.ent	__start
__start:
	br	$29,2f
2:	ldgp	$29,0($29)
	jsr	$26,start_kernel
	call_pal PAL_halt
	.end __start

	.align 5
	.globl	wrent
	.ent	wrent
wrent:
	.prologue 0
	call_pal PAL_wrent
	ret ($26)
	.end wrent

	.align 5
	.globl	wrkgp
	.ent	wrkgp
wrkgp:
	.prologue 0
	call_pal PAL_wrkgp
	ret ($26)
	.end wrkgp

	.align 5
	.globl	switch_to_osf_pal
	.ent	switch_to_osf_pal
switch_to_osf_pal:
	subq	$30,128,$30
	.frame	$30,128,$26
	stq	$26,0($30)
	stq	$1,8($30)
	stq	$2,16($30)
	stq	$3,24($30)
	stq	$4,32($30)
	stq	$5,40($30)
	stq	$6,48($30)
	stq	$7,56($30)
	stq	$8,64($30)
	stq	$9,72($30)
	stq	$10,80($30)
	stq	$11,88($30)
	stq	$12,96($30)
	stq	$13,104($30)
	stq	$14,112($30)
	stq	$15,120($30)
	.prologue 0

	stq	$30,0($17)	/* save KSP in PCB */

	bis	$30,$30,$20	/* a4 = KSP */
	br	$17,1f

	ldq	$26,0($30)
	ldq	$1,8($30)
	ldq	$2,16($30)
	ldq	$3,24($30)
	ldq	$4,32($30)
	ldq	$5,40($30)
	ldq	$6,48($30)
	ldq	$7,56($30)
	ldq	$8,64($30)
	ldq	$9,72($30)
	ldq	$10,80($30)
	ldq	$11,88($30)
	ldq	$12,96($30)
	ldq	$13,104($30)
	ldq	$14,112($30)
	ldq	$15,120($30)
	addq	$30,128,$30
	ret ($26)
1:	call_pal PAL_swppal
	.end	switch_to_osf_pal

	.align 3
	.globl	tbi
	.ent	tbi
tbi:
	.prologue 0
	call_pal PAL_tbi
	ret	($26)
	.end tbi

	.align 3
	.globl	halt
	.ent	halt
halt:
	.prologue 0
	call_pal PAL_halt
	.end halt