head.s

LINUX 2.6.17.4的源码

.Lagain1:
 	l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # ramdisk loc. is temp
        bas   %r14,.Lloader                    # load parameter file
        ltr   %r2,%r2                          # got anything ?
        bz    .Lnopf
	chi   %r2,895
	bnh   .Lnotrunc
	la    %r2,895
.Lnotrunc:
	l     %r4,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
	clc   0(3,%r4),.L_hdr		       # if it is HDRx
	bz    .Lagain1			       # skip dataset header
	clc   0(3,%r4),.L_eof		       # if it is EOFx
	bz    .Lagain1			       # skip dateset trailer
        la    %r5,0(%r4,%r2)
        lr    %r3,%r2
.Lidebc:
        tm    0(%r5),0x80                      # high order bit set ?
        bo    .Ldocv                           #  yes -> convert from EBCDIC
        ahi   %r5,-1
        bct   %r3,.Lidebc
        b     .Lnocv
.Ldocv:
        l     %r3,.Lcvtab
        tr    0(256,%r4),0(%r3)                # convert parameters to ascii
        tr    256(256,%r4),0(%r3)
        tr    512(256,%r4),0(%r3)
        tr    768(122,%r4),0(%r3)
.Lnocv: la    %r3,COMMAND_LINE-PARMAREA(%r12)  # load adr. of command line
	mvc   0(256,%r3),0(%r4)
	mvc   256(256,%r3),256(%r4)
	mvc   512(256,%r3),512(%r4)
	mvc   768(122,%r3),768(%r4)
        slr   %r0,%r0
        b     .Lcntlp
.Ldelspc:
        ic    %r0,0(%r2,%r3)
        chi   %r0,0x20                         # is it a space ?
        be    .Lcntlp
        ahi   %r2,1
        b     .Leolp
.Lcntlp:
        brct  %r2,.Ldelspc
.Leolp:
        slr   %r0,%r0
        stc   %r0,0(%r2,%r3)                   # terminate buffer
.Lnopf:

#
# load ramdisk from ipl device
#	
.Lagain2:
 	l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # addr of ramdisk
        bas   %r14,.Lloader                    # load ramdisk
 	st    %r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of ramdisk
        ltr   %r2,%r2
        bnz   .Lrdcont
        st    %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
.Lrdcont:
	l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)

	clc   0(3,%r2),.L_hdr		       # skip HDRx and EOFx 
	bz    .Lagain2
	clc   0(3,%r2),.L_eof
	bz    .Lagain2

#ifdef CONFIG_IPL_VM
#
# reset files in VM reader
#
        stidp __LC_CPUID                       # store cpuid
	tm    __LC_CPUID,0xff                  # running VM ?
	bno   .Lnoreset
        la    %r2,.Lreset              
        lhi   %r3,26
	diag  %r2,%r3,8
	la    %r5,.Lirb
	stsch 0(%r5)			       # check if irq is pending
	tm    30(%r5),0x0f		       # by verifying if any of the
	bnz   .Lwaitforirq		       # activity or status control
	tm    31(%r5),0xff		       # bits is set in the schib
	bz    .Lnoreset
.Lwaitforirq:
	mvc   0x78(8),.Lrdrnewpsw              # set up IO interrupt psw
.Lwaitrdrirq:
	lpsw  .Lrdrwaitpsw
.Lrdrint:
	c     %r1,0xb8                         # compare subchannel number
	bne   .Lwaitrdrirq
	la    %r5,.Lirb
	tsch  0(%r5)
.Lnoreset:
        b     .Lnoload

	.align 8
.Lrdrnewpsw:
	.long  0x00080000,0x80000000+.Lrdrint
.Lrdrwaitpsw:
	.long  0x020a0000,0x80000000+.Lrdrint
#endif

#
# everything loaded, go for it
#
.Lnoload:
        l     %r1,.Lstartup
        br    %r1

.Lparm:	.long  PARMAREA
.Lstartup: .long startup
.Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
.Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
        .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
        .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
.L_eof: .long  0xc5d6c600       /* C'EOF' */
.L_hdr: .long  0xc8c4d900       /* C'HDR' */

#endif  /* CONFIG_IPL */

#
# SALIPL loader support. Based on a patch by Rob van der Heij.
# This entry point is called directly from the SALIPL loader and
# doesn't need a builtin ipl record.
#
        .org  0x800
	.globl start
start:
	stm   %r0,%r15,0x07b0		# store registers
	basr  %r12,%r0
.base:
	l     %r11,.parm
	l     %r8,.cmd			# pointer to command buffer

	ltr   %r9,%r9			# do we have SALIPL parameters?
	bp    .sk8x8

	mvc   0(64,%r8),0x00b0		# copy saved registers
	xc    64(240-64,%r8),0(%r8)	# remainder of buffer
	tr    0(64,%r8),.lowcase	
	b     .gotr
.sk8x8:
	mvc   0(240,%r8),0(%r9)		# copy iplparms into buffer
.gotr:
	l     %r10,.tbl			# EBCDIC to ASCII table
	tr    0(240,%r8),0(%r10)
	stidp __LC_CPUID		# Are we running on VM maybe
	cli   __LC_CPUID,0xff
	bnz   .test
	.long 0x83300060		# diag 3,0,x'0060' - storage size
	b     .done
.test:
	mvc   0x68(8),.pgmnw		# set up pgm check handler
	l     %r2,.fourmeg
	lr    %r3,%r2
	bctr  %r3,%r0			# 4M-1
.loop:  iske  %r0,%r3
	ar    %r3,%r2
.pgmx:
	sr    %r3,%r2
	la    %r3,1(%r3)
.done:
        l     %r1,.memsize
	st    %r3,ARCH_OFFSET(%r1)
	slr   %r0,%r0
	st    %r0,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r11)
	st    %r0,INITRD_START+ARCH_OFFSET-PARMAREA(%r11)
	j     startup                   # continue with startup
.tbl:	.long _ebcasc			# translate table
.cmd:	.long COMMAND_LINE		# address of command line buffer
.parm:	.long PARMAREA
.memsize: .long memory_size
.fourmeg: .long 0x00400000      	# 4M
.pgmnw:	.long 0x00080000,.pgmx
.lowcase:
	.byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07 
	.byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
	.byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17 
	.byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
	.byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27 
	.byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
	.byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37 
	.byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
	.byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47 
	.byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
	.byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57 
	.byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
	.byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67 
	.byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
	.byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77 
	.byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f

	.byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87 
	.byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
	.byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97 
	.byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
	.byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7 
	.byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
	.byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7 
	.byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
	.byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87	# .abcdefg 
	.byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf	# hi
	.byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97 	# .jklmnop
	.byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf	# qr
	.byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7	# ..stuvwx
	.byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef	# yz
	.byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7 
	.byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff

.macro GET_IPL_DEVICE
.Lget_ipl_device:
	basr  %r12,0
.LGID:	l     %r1,0xb8			# get sid
	sll   %r1,15			# test if subchannel is enabled
	srl   %r1,31
	ltr   %r1,%r1
	bz    0(%r14)			# subchannel disabled
	l     %r1,0xb8
	la    %r5,.Lipl_schib-.LGID(%r12)
	stsch 0(%r5)		        # get schib of subchannel
	bnz   0(%r14)			# schib not available
	tm    5(%r5),0x01		# devno valid?
	bno   0(%r14)
	la    %r6,ipl_parameter_flags-.LGID(%r12)
	oi    3(%r6),0x01		# set flag
	la    %r2,ipl_devno-.LGID(%r12)
	mvc   0(2,%r2),6(%r5)		# store devno
	tm    4(%r5),0x80		# qdio capable device?
	bno   0(%r14)
	oi    3(%r6),0x02		# set flag

	# copy ipl parameters

	lhi   %r0,4096
	l     %r2,20(%r0)		# get address of parameter list
	lhi   %r3,IPL_PARMBLOCK_ORIGIN
	st    %r3,20(%r0)
	lhi   %r4,1
	cr    %r2,%r3			# start parameters < destination ?
	jl    0f
	lhi   %r1,1			# copy direction is upwards
	j     1f
0:	lhi   %r1,-1			# copy direction is downwards
	ar    %r2,%r0
	ar    %r3,%r0
	ar    %r2,%r1
	ar    %r3,%r1
1:	mvc   0(1,%r3),0(%r2)		# finally copy ipl parameters
	ar    %r3,%r1
	ar    %r2,%r1
	sr    %r0,%r4
	jne   1b
	b     0(%r14)

	.align 4
.Lipl_schib:
	.rept 13
	.long 0
	.endr

	.globl ipl_parameter_flags
ipl_parameter_flags:
	.long 0
	.globl ipl_devno
ipl_devno:
	.word 0
.endm

#ifdef CONFIG_64BIT
#include "head64.S"
#else
#include "head31.S"
#endif