linux/arch/s390/boot/head.S
Sven Schnelle 5ecb2da660 s390: support command lines longer than 896 bytes
Currently s390 supports a fixed maximum command line length of 896
bytes. This isn't enough as some installers are trying to pass all
configuration data via kernel command line, and even with zfcp alone
it is easy to generate really long command lines. Therefore extend
the command line to 4 kbytes.

In the parm area where the command line is stored there is no indication
of the maximum allowed length, so a new field which contains the maximum
length is added.

The parm area has always been initialized to zero, so with old kernels
this field would read zero. This is important because tools like zipl
could read this field. If it contains a number larger than zero zipl
knows the maximum length that can be stored in the parm area, otherwise
it must assume that it is booting a legacy kernel and only 896 bytes are
available.

The removing of trailing whitespace in head.S is also removed because
code to do this is already present in setup_boot_command_line().

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-10-26 15:21:31 +02:00

392 lines
11 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 1999, 2010
*
* Author(s): Hartmut Penner <hp@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Rob van der Heij <rvdhei@iae.nl>
* Heiko Carstens <heiko.carstens@de.ibm.com>
*
* There are 5 different IPL methods
* 1) load the image directly into ram at address 0 and do an PSW restart
* 2) linload will load the image from address 0x10000 to memory 0x10000
* and start the code thru LPSW 0x0008000080010000 (VM only, deprecated)
* 3) generate the tape ipl header, store the generated image on a tape
* and ipl from it
* In case of SL tape you need to IPL 5 times to get past VOL1 etc
* 4) generate the vm reader ipl header, move the generated image to the
* VM reader (use option NOH!) and do a ipl from reader (VM only)
* 5) direct call of start by the SALIPL loader
* We use the cpuid to distinguish between VM and native ipl
* params for kernel are pushed to 0x10400 (see setup.h)
*
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/sclp.h>
#define ARCH_OFFSET 4
#define EP_OFFSET 0x10008
#define EP_STRING "S390EP"
__HEAD
#define IPL_BS 0x730
.org 0
.long 0x00080000,0x80000000+iplstart # The first 24 bytes are loaded
.long 0x02000018,0x60000050 # by ipl to addresses 0-23.
.long 0x02000068,0x60000050 # (a PSW and two CCWs).
.fill 80-24,1,0x40 # bytes 24-79 are discarded !!
.long 0x020000f0,0x60000050 # The next 160 byte are loaded
.long 0x02000140,0x60000050 # to addresses 0x18-0xb7
.long 0x02000190,0x60000050 # They form the continuation
.long 0x020001e0,0x60000050 # of the CCW program started
.long 0x02000230,0x60000050 # by ipl and load the range
.long 0x02000280,0x60000050 # 0x0f0-0x730 from the image
.long 0x020002d0,0x60000050 # to the range 0x0f0-0x730
.long 0x02000320,0x60000050 # in memory. At the end of
.long 0x02000370,0x60000050 # the channel program the PSW
.long 0x020003c0,0x60000050 # at location 0 is loaded.
.long 0x02000410,0x60000050 # Initial processing starts
.long 0x02000460,0x60000050 # at 0x200 = iplstart.
.long 0x020004b0,0x60000050
.long 0x02000500,0x60000050
.long 0x02000550,0x60000050
.long 0x020005a0,0x60000050
.long 0x020005f0,0x60000050
.long 0x02000640,0x60000050
.long 0x02000690,0x60000050
.long 0x020006e0,0x20000050
.org __LC_RST_NEW_PSW # 0x1a0
.quad 0,iplstart
.org __LC_EXT_NEW_PSW # 0x1b0
.quad 0x0002000180000000,0x1b0 # disabled wait
.org __LC_PGM_NEW_PSW # 0x1d0
.quad 0x0000000180000000,startup_pgm_check_handler
.org __LC_IO_NEW_PSW # 0x1f0
.quad 0x0002000180000000,0x1f0 # disabled wait
.org 0x200
#
# subroutine to wait for end I/O
#
.Lirqwait:
mvc __LC_IO_NEW_PSW(16),.Lnewpsw # set up IO interrupt psw
lpsw .Lwaitpsw
.Lioint:
br %r14
.align 8
.Lnewpsw:
.quad 0x0000000080000000,.Lioint
.Lwaitpsw:
.long 0x020a0000,0x80000000+.Lioint
#
# subroutine for loading cards from the reader
#
.Lloader:
la %r4,0(%r14)
la %r3,.Lorb # r2 = address of orb into r2
la %r5,.Lirb # r4 = address of irb
la %r6,.Lccws
la %r7,20
.Linit:
st %r2,4(%r6) # initialize CCW data addresses
la %r2,0x50(%r2)
la %r6,8(%r6)
bct 7,.Linit
lctl %c6,%c6,.Lcr6 # set IO subclass mask
slr %r2,%r2
.Lldlp:
ssch 0(%r3) # load chunk of 1600 bytes
bnz .Llderr
.Lwait4irq:
bas %r14,.Lirqwait
c %r1,__LC_SUBCHANNEL_ID # compare subchannel number
bne .Lwait4irq
tsch 0(%r5)
slr %r0,%r0
ic %r0,8(%r5) # get device status
chi %r0,8 # channel end ?
be .Lcont
chi %r0,12 # channel end + device end ?
be .Lcont
l %r0,4(%r5)
s %r0,8(%r3) # r0/8 = number of ccws executed
mhi %r0,10 # *10 = number of bytes in ccws
lh %r3,10(%r5) # get residual count
sr %r0,%r3 # #ccws*80-residual=#bytes read
ar %r2,%r0
br %r4 # r2 contains the total size
.Lcont:
ahi %r2,0x640 # add 0x640 to total size
la %r6,.Lccws
la %r7,20
.Lincr:
l %r0,4(%r6) # update CCW data addresses
ahi %r0,0x640
st %r0,4(%r6)
ahi %r6,8
bct 7,.Lincr
b .Lldlp
.Llderr:
lpsw .Lcrash
.align 8
.Lorb: .long 0x00000000,0x0080ff00,.Lccws
.Lirb: .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
.Lcr6: .long 0xff000000
.Lloadp:.long 0,0
.align 8
.Lcrash:.long 0x000a0000,0x00000000
.align 8
.Lccws: .rept 19
.long 0x02600050,0x00000000
.endr
.long 0x02200050,0x00000000
iplstart:
mvi __LC_AR_MODE_ID,1 # set esame flag
slr %r0,%r0 # set cpuid to zero
lhi %r1,2 # mode 2 = esame (dump)
sigp %r1,%r0,0x12 # switch to esame mode
bras %r13,0f
.fill 16,4,0x0
0: lmh %r0,%r15,0(%r13) # clear high-order half of gprs
sam31 # switch to 31 bit addressing mode
lh %r1,__LC_SUBCHANNEL_ID # test if subchannel number
bct %r1,.Lnoload # is valid
l %r1,__LC_SUBCHANNEL_ID # load ipl subchannel number
la %r2,IPL_BS # load start address
bas %r14,.Lloader # load rest of ipl image
l %r12,.Lparm # pointer to parameter area
st %r1,IPL_DEVICE+ARCH_OFFSET-PARMAREA(%r12) # save ipl device number
#
# load parameter file from ipl device
#
.Lagain1:
l %r2,.Linitrd # ramdisk loc. is temp
bas %r14,.Lloader # load parameter file
ltr %r2,%r2 # got anything ?
bz .Lnopf
l %r3,MAX_COMMAND_LINE_SIZE+ARCH_OFFSET-PARMAREA(%r12)
ahi %r3,-1
clr %r2,%r3
bl .Lnotrunc
lr %r2,%r3
.Lnotrunc:
l %r4,.Linitrd
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
lr %r5,%r2
la %r6,COMMAND_LINE-PARMAREA(%r12)
lr %r7,%r2
ahi %r7,1
mvcl %r6,%r4
.Lnopf:
#
# load ramdisk from ipl device
#
.Lagain2:
l %r2,.Linitrd # addr of ramdisk
st %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
bas %r14,.Lloader # load ramdisk
st %r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of rd
ltr %r2,%r2
bnz .Lrdcont
st %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
.Lrdcont:
l %r2,.Linitrd
clc 0(3,%r2),.L_hdr # skip HDRx and EOFx
bz .Lagain2
clc 0(3,%r2),.L_eof
bz .Lagain2
#
# reset files in VM reader
#
stidp .Lcpuid # store cpuid
tm .Lcpuid,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:
bas %r14,.Lirqwait # wait for IO interrupt
c %r1,__LC_SUBCHANNEL_ID # compare subchannel number
bne .Lwaitforirq
la %r5,.Lirb
tsch 0(%r5)
.Lnoreset:
b .Lnoload
#
# everything loaded, go for it
#
.Lnoload:
l %r1,.Lstartup
br %r1
.Linitrd:.long _end # default address of initrd
.Lparm: .long PARMAREA
.Lstartup: .long startup
.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' */
.align 8
.Lcpuid:.fill 8,1,0
#
# normal startup-code, running in absolute addressing mode
# this is called either by the ipl loader or directly by PSW restart
# or linload or SALIPL
#
.org STARTUP_NORMAL_OFFSET
SYM_CODE_START(startup)
j startup_normal
.org EP_OFFSET
#
# This is a list of s390 kernel entry points. At address 0x1000f the number of
# valid entry points is stored.
#
# IMPORTANT: Do not change this table, it is s390 kernel ABI!
#
.ascii EP_STRING
.byte 0x00,0x01
#
# kdump startup-code, running in 64 bit absolute addressing mode
#
.org STARTUP_KDUMP_OFFSET
j startup_kdump
SYM_CODE_END(startup)
SYM_CODE_START_LOCAL(startup_normal)
mvi __LC_AR_MODE_ID,1 # set esame flag
slr %r0,%r0 # set cpuid to zero
lhi %r1,2 # mode 2 = esame (dump)
sigp %r1,%r0,0x12 # switch to esame mode
bras %r13,0f
.fill 16,4,0x0
0: lmh %r0,%r15,0(%r13) # clear high-order half of gprs
sam64 # switch to 64 bit addressing mode
basr %r13,0 # get base
.LPG0:
mvc __LC_EXT_NEW_PSW(16),.Lext_new_psw-.LPG0(%r13)
mvc __LC_PGM_NEW_PSW(16),.Lpgm_new_psw-.LPG0(%r13)
mvc __LC_IO_NEW_PSW(16),.Lio_new_psw-.LPG0(%r13)
xc 0x200(256),0x200 # partially clear lowcore
xc 0x300(256),0x300
xc 0xe00(256),0xe00
xc 0xf00(256),0xf00
lctlg %c0,%c15,.Lctl-.LPG0(%r13) # load control registers
stcke __LC_BOOT_CLOCK
mvc __LC_LAST_UPDATE_CLOCK(8),__LC_BOOT_CLOCK+1
spt 6f-.LPG0(%r13)
mvc __LC_LAST_UPDATE_TIMER(8),6f-.LPG0(%r13)
larl %r15,_stack_end-STACK_FRAME_OVERHEAD
brasl %r14,sclp_early_setup_buffer
brasl %r14,verify_facilities
brasl %r14,startup_kernel
SYM_CODE_END(startup_normal)
.align 8
6: .long 0x7fffffff,0xffffffff
.Lext_new_psw:
.quad 0x0002000180000000,0x1b0 # disabled wait
.Lpgm_new_psw:
.quad 0x0000000180000000,startup_pgm_check_handler
.Lio_new_psw:
.quad 0x0002000180000000,0x1f0 # disabled wait
.Lctl: .quad 0x04040000 # cr0: AFP registers & secondary space
.quad 0 # cr1: primary space segment table
.quad 0 # cr2: dispatchable unit control table
.quad 0 # cr3: instruction authorization
.quad 0xffff # cr4: instruction authorization
.quad 0 # cr5: primary-aste origin
.quad 0 # cr6: I/O interrupts
.quad 0 # cr7: secondary space segment table
.quad 0x0000000000008000 # cr8: access registers translation
.quad 0 # cr9: tracing off
.quad 0 # cr10: tracing off
.quad 0 # cr11: tracing off
.quad 0 # cr12: tracing off
.quad 0 # cr13: home space segment table
.quad 0xc0000000 # cr14: machine check handling off
.quad 0 # cr15: linkage stack operations
#include "head_kdump.S"
#
# This program check is active immediately after kernel start
# and until early_pgm_check_handler is set in kernel/early.c
# It simply saves general/control registers and psw in
# the save area and does disabled wait with a faulty address.
#
SYM_CODE_START_LOCAL(startup_pgm_check_handler)
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
la %r8,4095
stctg %c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r8)
stmg %r0,%r7,__LC_GPREGS_SAVE_AREA-4095(%r8)
mvc __LC_GPREGS_SAVE_AREA-4095+64(64,%r8),__LC_SAVE_AREA_SYNC
mvc __LC_PSW_SAVE_AREA-4095(16,%r8),__LC_PGM_OLD_PSW
mvc __LC_RETURN_PSW(16),__LC_PGM_OLD_PSW
ni __LC_RETURN_PSW,0xfc # remove IO and EX bits
ni __LC_RETURN_PSW+1,0xfb # remove MCHK bit
oi __LC_RETURN_PSW+1,0x2 # set wait state bit
larl %r9,.Lold_psw_disabled_wait
stg %r9,__LC_PGM_NEW_PSW+8
larl %r15,_dump_info_stack_end-STACK_FRAME_OVERHEAD
brasl %r14,print_pgm_check_info
.Lold_psw_disabled_wait:
la %r8,4095
lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r8)
lpswe __LC_RETURN_PSW # disabled wait
SYM_CODE_END(startup_pgm_check_handler)
#
# params at 10400 (setup.h)
# Must be keept in sync with struct parmarea in setup.h
#
.org PARMAREA
SYM_DATA_START(parmarea)
.quad 0 # IPL_DEVICE
.quad 0 # INITRD_START
.quad 0 # INITRD_SIZE
.quad 0 # OLDMEM_BASE
.quad 0 # OLDMEM_SIZE
.quad kernel_version # points to kernel version string
.quad COMMAND_LINE_SIZE
.org COMMAND_LINE
.byte "root=/dev/ram0 ro"
.byte 0
.org PARMAREA+__PARMAREA_SIZE
SYM_DATA_END(parmarea)