--- /dev/null
+/*
+ * arch/s390/kernel/head31.S
+ *
+ * (C) Copyright IBM Corp. 2005
+ *
+ * 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
+.LPG1: l %r1, .Lget_ipl_device_addr-.LPG1(%r13)
+ basr %r14, %r1
+ lctl %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
+ la %r12,_pstart-.LPG1(%r13) # pointer to parameter area
+ # move IPL device to lowcore
+ mvc __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
+
+#
+# clear bss memory
+#
+ l %r2,.Lbss_bgn-.LPG1(%r13) # start of bss
+ l %r3,.Lbss_end-.LPG1(%r13) # end of bss
+ sr %r3,%r2 # length of bss
+ sr %r4,%r4
+ sr %r5,%r5 # set src,length and pad to zero
+ sr %r0,%r0
+ mvcle %r2,%r4,0 # clear mem
+ jo .-4 # branch back, if not finish
+
+ l %r2,.Lrcp-.LPG1(%r13) # Read SCP forced command word
+.Lservicecall:
+ stosm .Lpmask-.LPG1(%r13),0x01 # authorize ext interrupts
+
+ stctl %r0, %r0,.Lcr-.LPG1(%r13) # get cr0
+ la %r1,0x200 # set bit 22
+ o %r1,.Lcr-.LPG1(%r13) # or old cr0 with r1
+ st %r1,.Lcr-.LPG1(%r13)
+ lctl %r0, %r0,.Lcr-.LPG1(%r13) # load modified cr0
+
+ mvc __LC_EXT_NEW_PSW(8),.Lpcext-.LPG1(%r13) # set postcall psw
+ la %r1, .Lsclph-.LPG1(%r13)
+ a %r1,__LC_EXT_NEW_PSW+4 # set handler
+ st %r1,__LC_EXT_NEW_PSW+4
+
+ la %r4,_pstart-.LPG1(%r13) # %r4 is our index for sccb stuff
+ la %r1, .Lsccb-PARMAREA(%r4) # our sccb
+ .insn rre,0xb2200000,%r2,%r1 # service call
+ ipm %r1
+ srl %r1,28 # get cc code
+ xr %r3, %r3
+ chi %r1,3
+ be .Lfchunk-.LPG1(%r13) # leave
+ chi %r1,2
+ be .Lservicecall-.LPG1(%r13)
+ lpsw .Lwaitsclp-.LPG1(%r13)
+.Lsclph:
+ lh %r1,.Lsccbr-PARMAREA(%r4)
+ chi %r1,0x10 # 0x0010 is the sucess code
+ je .Lprocsccb # let's process the sccb
+ chi %r1,0x1f0
+ bne .Lfchunk-.LPG1(%r13) # unhandled error code
+ c %r2, .Lrcp-.LPG1(%r13) # Did we try Read SCP forced
+ bne .Lfchunk-.LPG1(%r13) # if no, give up
+ l %r2, .Lrcp2-.LPG1(%r13) # try with Read SCP
+ b .Lservicecall-.LPG1(%r13)
+.Lprocsccb:
+ lhi %r1,0
+ icm %r1,3,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
+ jnz .Lscnd
+ lhi %r1,0x800 # otherwise report 2GB
+.Lscnd:
+ lhi %r3,0x800 # limit reported memory size to 2GB
+ cr %r1,%r3
+ jl .Lno2gb
+ lr %r1,%r3
+.Lno2gb:
+ xr %r3,%r3 # same logic
+ ic %r3,.Lscpa1-PARMAREA(%r4)
+ chi %r3,0x00
+ jne .Lcompmem
+ l %r3,.Lscpa2-PARMAREA(%r13)
+.Lcompmem:
+ mr %r2,%r1 # mem in MB on 128-bit
+ l %r1,.Lonemb-.LPG1(%r13)
+ mr %r2,%r1 # mem size in bytes in %r3
+ b .Lfchunk-.LPG1(%r13)
+
+ .align 4
+.Lget_ipl_device_addr:
+ .long .Lget_ipl_device
+.Lpmask:
+ .byte 0
+.align 8
+.Lpcext:.long 0x00080000,0x80000000
+.Lcr:
+ .long 0x00 # place holder for cr0
+.Lwaitsclp:
+ .long 0x010a0000,0x80000000 + .Lsclph
+.Lrcp:
+ .int 0x00120001 # Read SCP forced code
+.Lrcp2:
+ .int 0x00020001 # Read SCP code
+.Lonemb:
+ .int 0x100000
+.Lfchunk:
+
+#
+# find memory chunks.
+#
+ lr %r9,%r3 # end of mem
+ mvc __LC_PGM_NEW_PSW(8),.Lpcmem-.LPG1(%r13)
+ la %r1,1 # test in increments of 128KB
+ sll %r1,17
+ l %r3,.Lmchunk-.LPG1(%r13) # get pointer to memory_chunk array
+ slr %r4,%r4 # set start of chunk to zero
+ slr %r5,%r5 # set end of chunk to zero
+ slr %r6,%r6 # set access code to zero
+ la %r10, MEMORY_CHUNKS # number of chunks
+.Lloop:
+ tprot 0(%r5),0 # test protection of first byte
+ ipm %r7
+ srl %r7,28
+ clr %r6,%r7 # compare cc with last access code
+ be .Lsame-.LPG1(%r13)
+ b .Lchkmem-.LPG1(%r13)
+.Lsame:
+ ar %r5,%r1 # add 128KB to end of chunk
+ bno .Lloop-.LPG1(%r13) # r1 < 0x80000000 -> loop
+.Lchkmem: # > 2GB or tprot got a program check
+ clr %r4,%r5 # chunk size > 0?
+ be .Lchkloop-.LPG1(%r13)
+ st %r4,0(%r3) # store start address of chunk
+ lr %r0,%r5
+ slr %r0,%r4
+ st %r0,4(%r3) # store size of chunk
+ st %r6,8(%r3) # store type of chunk
+ la %r3,12(%r3)
+ l %r4,.Lmemsize-.LPG1(%r13) # address of variable memory_size
+ st %r5,0(%r4) # store last end to memory size
+ ahi %r10,-1 # update chunk number
+.Lchkloop:
+ lr %r6,%r7 # set access code to last cc
+ # we got an exception or we're starting a new
+ # chunk , we must check if we should
+ # still try to find valid memory (if we detected
+ # the amount of available storage), and if we
+ # have chunks left
+ xr %r0,%r0
+ clr %r0,%r9 # did we detect memory?
+ je .Ldonemem # if not, leave
+ chi %r10,0 # do we have chunks left?
+ je .Ldonemem
+ alr %r5,%r1 # add 128KB to end of chunk
+ lr %r4,%r5 # potential new chunk
+ clr %r5,%r9 # should we go on?
+ jl .Lloop
+.Ldonemem:
+ l %r12,.Lmflags-.LPG1(%r13) # get address of machine_flags
+#
+# find out if we are running under VM
+#
+ stidp __LC_CPUID # store cpuid
+ tm __LC_CPUID,0xff # running under VM ?
+ bno .Lnovm-.LPG1(%r13)
+ oi 3(%r12),1 # set VM flag
+.Lnovm:
+ lh %r0,__LC_CPUID+4 # get cpu version
+ chi %r0,0x7490 # running on a P/390 ?
+ bne .Lnop390-.LPG1(%r13)
+ oi 3(%r12),4 # set P/390 flag
+.Lnop390:
+
+#
+# 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:
+
+ 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
+.Lpcmem:.long 0x00080000,0x80000000 + .Lchkmem
+.Lpcfpu:.long 0x00080000,0x80000000 + .Lchkfpu
+.Lpccsp:.long 0x00080000,0x80000000 + .Lchkcsp
+.Lpcmvpg:.long 0x00080000,0x80000000 + .Lchkmvpg
+.Lpcidte:.long 0x00080000,0x80000000 + .Lchkidte
+.Lmemsize:.long memory_size
+.Lmchunk:.long memory_chunk
+.Lmflags:.long machine_flags
+.Lbss_bgn: .long __bss_start
+.Lbss_end: .long _end
+
+ .org PARMAREA-64
+.Lduct: .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+
+#
+# params at 10400 (setup.h)
+#
+ .org PARMAREA
+ .global _pstart
+_pstart:
+ .long 0,0 # IPL_DEVICE
+ .long 0,RAMDISK_ORIGIN # INITRD_START
+ .long 0,RAMDISK_SIZE # INITRD_SIZE
+
+ .org COMMAND_LINE
+ .byte "root=/dev/ram0 ro"
+ .byte 0
+ .org 0x11000
+.Lsccb:
+ .hword 0x1000 # length, one page
+ .byte 0x00,0x00,0x00
+ .byte 0x80 # variable response bit set
+.Lsccbr:
+ .hword 0x00 # response code
+.Lscpincr1:
+ .hword 0x00
+.Lscpa1:
+ .byte 0x00
+ .fill 89,1,0
+.Lscpa2:
+ .int 0x00
+.Lscpincr2:
+ .quad 0x00
+ .fill 3984,1,0
+ .org 0x12000
+ .global _pend
+_pend:
+
+ GET_IPL_DEVICE
+
+#ifdef CONFIG_SHARED_KERNEL
+ .org 0x100000
+#endif
+
+#
+# startup-code, running in virtual mode
+#
+ .globl _stext
+_stext: basr %r13,0 # get base
+.LPG3:
+#
+# Setup stack
+#
+ l %r15,.Linittu-.LPG3(%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
+
+# 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
+.Linittu:.long init_thread_union
+.Lstart:.long start_kernel
+.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
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