out

来自「国产CPU－龙芯（loongson)BIOS源代码」· 代码 · 共 845 行

# 1 "/home/fxzhang/software/pmon/src/Targets/gfcr/gfcr/start.S"
# 1 "machine/asm.h" 1
 

 















































# 1 "machine/regdef.h" 1
 

 










































































# 51 "machine/asm.h" 2















 







# 83 "machine/asm.h"


 











 


# 115 "machine/asm.h"




 

















 












 













 













 







 





















 
















# 1 "/home/fxzhang/software/pmon/src/Targets/gfcr/gfcr/start.S" 2

# 1 "/home/fxzhang/software/pmon/src/Targets/gfcr/include/mipsregs.h" 1
 

































# 2 "/home/fxzhang/software/pmon/src/Targets/gfcr/gfcr/start.S" 2

# 1 "/home/fxzhang/software/pmon/src/Targets/gfcr/include/address.h" 1
 


# 3 "/home/fxzhang/software/pmon/src/Targets/gfcr/gfcr/start.S" 2


 















#################
#UART          #
#################




######################################
#ROM Exception Entry	             #
######################################

	.text
	.ent	reset_exception

reset_exception:

	.set noreorder
	.set noat

	b		start		# Reset Exception Entry
	move	$26 , $0 

	.set reorder

	.org 0x380	
	b		excHandler	# General Exception Entry, in ROM
						#it located at physaddr 0x1bfc0380
	.end	reset_exception
	

######################################
#ROM BIOS Entry       #
######################################
	.comm	stack, 0x3000 		# Stack area
 								
	.set	at
	.globl 	start
	.ent 	start

start:					# This is the entry point of the BIOS ROM Image.
	.globl 	__start
	.aent 	__start

__start:
	move	$26 , $0 

##########################################
#Force Code to Run in K1 Seg.	 #
#Now the cache of CPU is invalid  #
##########################################
	.set	noreorder
	.set	nomacro

	bal		1f
	lui		$8 , 0xa0000000 >>16		# in fact, here a nop instruction inserted
1:	or		$31 , $8 			# by compiler in case of the delay slot's effect.
	addiu		$31 , 16			# 16 = 4 * sizeof(LX-1 inst size).
	j		$31 			# now $31  = . + 1
	nop

	.set	macro
	.set	reorder
	
######################################
#Set up a K1seg stack         #
######################################
	.set reorder
1:	la      $29 , stack + 0x3000  - 24
	or      $29 , $29 , 0xa0000000 

######################################
#Calculate Re-location code	     #
######################################

	bal		1f
1:	la		$9 , 1b			# Little trick to calculate relocation offset.
	subu		$30 , $31 , $9 

# 126 "/home/fxzhang/software/pmon/src/Targets/gfcr/gfcr/start.S"


################################
#Initailize SDRAM Interface #
################################

        li  $4 ,0xbf000000
#config
	li $5 , 0x20000000	
    sw  $5 ,4($4 )
#timing
	li  $5 ,0x01040242
    sw  $5 ,0($4 )
#config
	li $5 , 0x209800c6	
    sw  $5 ,4($4 )

#bal doMemTestX	# test SDRAM module

######################################
#ROM => RAM, Text RAM Section #
######################################
	la		$8 , _ftextram
	add		$8 , $30 		# $8  = ROM addr of text segs' end

	la		$9 , _ftextram		# $9 	destination	$9   
	or		$9 , 0xa0000000 

	la		$10 ,	_etextram	# $10  is the length of textram+rodat segs.
	or		$10 , 0xa0000000 
	addu	$10 , 4  - 1
	and		$10 , - 4 		# end address aligned

	.set	noreorder
1:	lw		$11 , 0($8 )		# $11 : source context
	addu	$8 , 4 			# $8 : source address register
	addu	$9 , 4 			# $9 : destination address register
	bne		$9 , $10 , 1b		# $10 : end address register
    sw		$11 , - 4 ($9 )

######################################
#ROM => RAM, Data  Sections   #
######################################
	.set	reorder
2:
	la		$8 , _etextram
	addu	$8 , $30 			# RELOC
	or		$8 , 0xa0000000 	# $8 : data section start address in ROM
	addu	$8 , 32 -1
	and		$8 , - 32 

	la		$9 , _fdata
	or		$9 , 0xa0000000 	# $9 : data section start address in RAM
	la		$10 , _edata
	or		$10 , 0xa0000000 	# $10 : data section end address in RAM

	addu	$10 , 4 -1
	and		$10 , - 4 
	beq		$9 , $10 , zbss

	.set	noreorder
1:	lw		$11 , 0($8 )
	addu	$8 , 4 
	addu	$9 , 4 
	bne		$9 , $10 , 1b
    sw		$11 , - 4 ($9 )

######################################
#Clean BSS sections         #
######################################
	.set	reorder
zbss:	
	#clear bss
	la		$2 , _fbss		# BSS section pre-compiled start in RAM
	la		$3 , end			# BSS section pre-compiled end in RAM
	or		$2 , 0xa0000000 
	or		$3 , 0xa0000000 

	1:	.set	noreorder
	sw		$0, 0($2 )
	sw		$0, 4($2 )
	sw		$0, 8($2 )
	addu	$2 , 16
	bltu	$2 , $3 , 1b
	sw		$0, -4($2 )		# use delay slot to fill 12($2 )

######################################
#Copy Exception Vectors to RAM      #
######################################
	.set	reorder
	la      $4 , excHandler
	la      $5 , eExcHandler
	li      $6 , 0x0000180           
	bal     copyExcVec
	nop

######################################
#Disable Interrupt              #
######################################

	mfc0	$8 , $12 
	and 	$8 , 0xfffffffe	# By default it will be disabled.
	mtc0	$8 , $12 	# Set CPU to disable interrupt.
	nop
	
######################################
#Init&Flush the Cache of CPU	 #
######################################
	mfc0	$8 , $16 
	and		$8 , 0xfffffff8
	or		$8 , 0x2			# disable,!default value is not it!
	mtc0	$8 , $16 			# Set CPU to disable cache.
	nop

######################################
#Re-set stack pointer for C code    #
######################################
	la      $29 , stack + 0x3000  - 24	# Re-Set stack pointer

######################################
#Jump to normal BIOS startup code #	  
######################################
#la		$4 , start_bios
	la		$4 , initmips
	jr		$4 
	nop

	1:	bal		1b
	j		start

	.end start

##################################################
#copyExcVec Function Entry		 #
##
#Params:					 #
#a0 = Src ExcVec Start Addr	 #
#a1 = Src ExcVec End   Addr	 #
#a2 = Dst ExcVec Addr		 #
#Volatile:				 #
#a0, $5 				 #
##################################################

	.globl copyExcVec
	.ent copyExcVec

	copyExcVec:
	or      $8 , $4 , 0xa0000000 			# Force $4 & $5  to K1 Seg
	or      $9 , $5 , 0xa0000000 
	or      $6 , 0xa0000000 			# Although $6  in K1, but it's in RAM
1:  lw      $2 , ($8 )
	sw      $2 , ($6 )
	addu    $8 , 4 
	addu    $6 , 4 
	bltu    $8 , $9 , 1b
	j       $31 
	.end copyExcVec

######################################
#General Exception Handler Entry  #
######################################

	.globl 	excHandler
	.ent 	excHandler





excHandler:
	.set noat
	.rdata;98: .asciz  "EXCEPTION!CAUSE=" ; .text; la $4 , 98b; bal puts; nop ;
	mfc0	$4 , $13 
	la	$9 , put32
	jalr    $9  
	nop
	.rdata;98: .asciz  " EPC=" ; .text; la $4 , 98b; bal puts; nop ;
	mfc0	$4 , $14 
	la	$9 , put32
	jalr	$9 
	nop
	.rdata;98: .asciz  " BADVADDR=" ; .text; la $4 , 98b; bal puts; nop ;
	mfc0	$4 , $8 
	la 	$9 , put32
	jalr	$9 
	nop
	.rdata;98: .asciz  " STATUS=" ; .text; la $4 , 98b; bal puts; nop ;
	mfc0	$4 , $12 
	la 	$9 , put32
	jalr	$9 
	nop
	
	.set mips3
	eret
	.set mips0
eExcHandler:					# End of General Exception Handler
	.set at
	.end excHandler





 
.align	3;	.globl  tgt_putchar ;	.ent  tgt_putchar , 0;	 tgt_putchar : ;	.frame $29 , 0, $31 ;	 	  

   	li	$8 , (0x13) 			# timeout
1:	lbu	$9 , ((0xa0000000  + 0x1f004090  + 0x5) )		# get LSR
	and	$9 , 0x20			# tx ready?
	bnez	$9 , 1f				# can write

2:	li	$9 , (0x12) 			# Wait a while
3:	subu	$9 , 1
	bnez	$9 , 3b

	subu	$8 , 1				# continue until timeout 
	bnez	$8 , 1b

1:	sb	$4 , ((0xa0000000  + 0x1f004090  + 0x0) )		# write data
	j	$31 
	nop
.end  tgt_putchar  

######################################
#Print 32bit Integer in reg $4       #
######################################

.align	3;	.globl  put32 ;	.ent  put32 , 0;	 put32 : ;	.frame $29 , 0, $31 ;	 	  
	.set noreorder
	move	$25 , $31 
	move	$14 , $4 
	li	$15 , 32

2:	subu	$15 , 4
	srl $4 , $15 
	and $4 , 0x0F
	blt	$4 , 0x0A, 3f
	nop
	subu	$4 , 0x0a
	addu	$4 , 'A'
	j	4f
	nop

3:	addu	$4 , '0'

4:	bal	tgt_putchar
	nop

	move	$4 , $14 
	bnez	$15 , 2b
	nop
	
	move	$31 , $25 
	j	$31 
	nop
	.set reorder
.end  put32  

 



 
.align	3;	.globl  puts ;	.ent  puts , 0;	 puts : ;	.frame $29 , 0, $31 ;	 	  
	.set noreorder
        move    $25 , $31 
        move    $5 , $4 
        lbu     $4 , 0($5 )
1:
        beqz    $4 , 2f
        nop
        bal     tgt_putchar
        addiu   $5 , 1
        b       1b
        lbu     $4 , 0($5 )

2:
        j       $25 
        nop
	.set reorder
.end  puts  


######################################
#Test SDRAM Module            #
######################################
.align	3;	.globl  doMemTestX ;	.ent  doMemTestX , 0;	 doMemTestX : ;	.frame $29 , 0, $31 ;	 	  
	.set macro
	.set noreorder







	





	move	$25 , $31 

 
	.rdata;98: .asciz  "\r\nSDRAM Testing..." ; .text; la $4 , 98b; bal puts; nop ;

	li	$5 , 0x0
	li	$6 , 0x0
	li	$7 , 0x0

	li	$16 , 0x1
	li	$17 , 0x2
	li	$18 , 0x3
	li	$19 , 0x4
	nop
	
	li	$10 , (0xA0000000) 
	li	$11 , (0xA8000000) 

1:

	sw	$16 , ($10 )
	sh	$17 , 4($10 )
	sb	$18 , 6($10 )

	move 	$4 ,  $10 		
	nop
	bal	put32
	nop

	.rdata;98: .asciz  "\r\n" ; .text; la $4 , 98b; bal puts; nop 

	lw	$19 , ($10 )
	bne	$19 , $16 , 3f
	nop

	lhu	$20 , 4($10 )
	and     $12 , $17 , 0xffff
	bne	$20 , $12 , 3f
	nop

	lbu	$21 , 6($10 )
	and     $12 , $18 , 0xff
	bne	$21 , $12 , 3f
	nop
	
2:	addiu	$10 , (0x01000) 

	addiu	$16 , 0x1
	addiu	$17 , 0x1
	addiu	$18 , 0x1

	bne	$10 , $11 , 1b
	nop

	.rdata;98: .asciz  "\r\nTest end.\r\n" ; .text; la $4 , 98b; bal puts; nop 
	
	move	$31 , $25 
	j	$31 
	nop

########################
#some error occured ! #
########################

3:	
	.rdata;98: .asciz  "\r\nMISMATCH at locate:" ; .text; la $4 , 98b; bal puts; nop 

	move 	$4 ,  $10 		

	nop
	bal	put32
	nop

	.rdata;98: .asciz  "\r\nExpect:" ; .text; la $4 , 98b; bal puts; nop 

	move	$4 , $16 
	bal	put32	
	nop

	bal	tgt_putchar	;	li	$4 , ( ' ' ) 

	move	$4 , $17 
	bal	put32	
	nop

	bal	tgt_putchar	;	li	$4 , ( ' ' ) 

	move	$4 , $18 
	bal	put32	
	nop

	.rdata;98: .asciz  " Got:" ; .text; la $4 , 98b; bal puts; nop 

	move	$4 , $19  
	bal	put32	
	nop

	bal	tgt_putchar	;	li	$4 , ( ' ' ) 

	move	$4 , $20 
	bal	put32	
	nop

	bal	tgt_putchar	;	li	$4 , ( ' ' ) 

	move	$4 , $21 
	bal	put32	
	nop

	.rdata;98: .asciz  "\r\n" ; .text; la $4 , 98b; bal puts; nop 

	b	2b
	nop

	.set reorder
.end  doMemTestX