linux/arch/s390/kernel/head31.S
Heiko Carstens 615b04b301 [S390] nss: Free unused memory in kernel image.
With CONFIG_SHARED_KERNEL the kernel text segment that might be in a
read only memory sections starts at 1MB. Memory between 0x12000 and
0x100000 is unused then. Free this, so we have appr. an extra MB
of memory available.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-21 10:55:37 +01:00

184 lines
4.7 KiB
ArmAsm

/*
* arch/s390/kernel/head31.S
*
* Copyright (C) IBM Corp. 2005,2006
*
* 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>
*
*/
#
# startup-code at 0x10000, running in absolute addressing mode
# this is called either by the ipl loader or directly by PSW restart
# or linload or SALIPL
#
.org 0x10000
startup:basr %r13,0 # get base
.LPG0: l %r13,0f-.LPG0(%r13)
b 0(%r13)
0: .long startup_continue
#
# params at 10400 (setup.h)
#
.org PARMAREA
.long 0,0 # IPL_DEVICE
.long 0,0 # INITRD_START
.long 0,0 # INITRD_SIZE
.org COMMAND_LINE
.byte "root=/dev/ram0 ro"
.byte 0
.org 0x11000
startup_continue:
basr %r13,0 # get base
.LPG1: mvi __LC_AR_MODE_ID,0 # set ESA flag (mode 0)
lctl %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
l %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
# move IPL device to lowcore
mvc __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
#
# Setup stack
#
l %r15,.Linittu-.LPG1(%r13)
mvc __LC_CURRENT(4),__TI_task(%r15)
ahi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
st %r15,__LC_KERNEL_STACK # set end of kernel stack
ahi %r15,-96
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
#
# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
# and create a kernel NSS if the SAVESYS= parm is defined
#
l %r14,.Lstartup_init-.LPG1(%r13)
basr %r14,%r14
l %r12,.Lmflags-.LPG1(%r13) # get address of machine_flags
#
# find out if we have an IEEE fpu
#
mvc __LC_PGM_NEW_PSW(8),.Lpcfpu-.LPG1(%r13)
efpc %r0,0 # test IEEE extract fpc instruction
oi 3(%r12),2 # set IEEE fpu flag
.Lchkfpu:
#
# find out if we have the CSP instruction
#
mvc __LC_PGM_NEW_PSW(8),.Lpccsp-.LPG1(%r13)
la %r0,0
lr %r1,%r0
la %r2,4
csp %r0,%r2 # Test CSP instruction
oi 3(%r12),8 # set CSP flag
.Lchkcsp:
#
# find out if we have the MVPG instruction
#
mvc __LC_PGM_NEW_PSW(8),.Lpcmvpg-.LPG1(%r13)
sr %r0,%r0
la %r1,0
la %r2,0
mvpg %r1,%r2 # Test CSP instruction
oi 3(%r12),16 # set MVPG flag
.Lchkmvpg:
#
# find out if we have the IDTE instruction
#
mvc __LC_PGM_NEW_PSW(8),.Lpcidte-.LPG1(%r13)
.long 0xb2b10000 # store facility list
tm 0xc8,0x08 # check bit for clearing-by-ASCE
bno .Lchkidte-.LPG1(%r13)
lhi %r1,2094
lhi %r2,0
.long 0xb98e2001
oi 3(%r12),0x80 # set IDTE flag
.Lchkidte:
#
# find out if the diag 0x9c is available
#
mvc __LC_PGM_NEW_PSW(8),.Lpcdiag9c-.LPG1(%r13)
stap __LC_CPUID+4 # store cpu address
lh %r1,__LC_CPUID+4
diag %r1,0,0x9c # test diag 0x9c
oi 2(%r12),1 # set diag9c flag
.Lchkdiag9c:
lpsw .Lentry-.LPG1(13) # jump to _stext in primary-space,
# virtual and never return ...
.align 8
.Lentry:.long 0x00080000,0x80000000 + _stext
.Lctl: .long 0x04b50002 # cr0: various things
.long 0 # cr1: primary space segment table
.long .Lduct # cr2: dispatchable unit control table
.long 0 # cr3: instruction authorization
.long 0 # cr4: instruction authorization
.long 0xffffffff # cr5: primary-aste origin
.long 0 # cr6: I/O interrupts
.long 0 # cr7: secondary space segment table
.long 0 # cr8: access registers translation
.long 0 # cr9: tracing off
.long 0 # cr10: tracing off
.long 0 # cr11: tracing off
.long 0 # cr12: tracing off
.long 0 # cr13: home space segment table
.long 0xc0000000 # cr14: machine check handling off
.long 0 # cr15: linkage stack operations
.Lduct: .long 0,0,0,0,0,0,0,0
.long 0,0,0,0,0,0,0,0
.Lpcfpu:.long 0x00080000,0x80000000 + .Lchkfpu
.Lpccsp:.long 0x00080000,0x80000000 + .Lchkcsp
.Lpcmvpg:.long 0x00080000,0x80000000 + .Lchkmvpg
.Lpcidte:.long 0x00080000,0x80000000 + .Lchkidte
.Lpcdiag9c:.long 0x00080000,0x80000000 + .Lchkdiag9c
.Lmchunk:.long memory_chunk
.Lmflags:.long machine_flags
.Lbss_bgn: .long __bss_start
.Lbss_end: .long _end
.Lparmaddr: .long PARMAREA
.Linittu: .long init_thread_union
.Lstartup_init:
.long startup_init
.org 0x12000
.globl _ehead
_ehead:
#ifdef CONFIG_SHARED_KERNEL
.org 0x100000
#endif
#
# startup-code, running in absolute addressing mode
#
.globl _stext
_stext: basr %r13,0 # get base
.LPG3:
# check control registers
stctl %c0,%c15,0(%r15)
oi 2(%r15),0x40 # enable sigp emergency signal
oi 0(%r15),0x10 # switch on low address protection
lctl %c0,%c15,0(%r15)
#
lam 0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
l %r14,.Lstart-.LPG3(%r13)
basr %r14,%r14 # call start_kernel
#
# We returned from start_kernel ?!? PANIK
#
basr %r13,0
lpsw .Ldw-.(%r13) # load disabled wait psw
#
.align 8
.Ldw: .long 0x000a0000,0x00000000
.Lstart:.long start_kernel
.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0