xref: /openbmc/linux/arch/s390/kernel/head64.S (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1/*
2 *  arch/s390/kernel/head.S
3 *
4 *  S390 version
5 *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 *    Author(s): Hartmut Penner (hp@de.ibm.com),
7 *               Martin Schwidefsky (schwidefsky@de.ibm.com),
8 *               Rob van der Heij (rvdhei@iae.nl)
9 *
10 * There are 5 different IPL methods
11 *  1) load the image directly into ram at address 0 and do an PSW restart
12 *  2) linload will load the image from address 0x10000 to memory 0x10000
13 *     and start the code thru LPSW 0x0008000080010000 (VM only, deprecated)
14 *  3) generate the tape ipl header, store the generated image on a tape
15 *     and ipl from it
16 *     In case of SL tape you need to IPL 5 times to get past VOL1 etc
17 *  4) generate the vm reader ipl header, move the generated image to the
18 *     VM reader (use option NOH!) and do a ipl from reader (VM only)
19 *  5) direct call of start by the SALIPL loader
20 *  We use the cpuid to distinguish between VM and native ipl
21 *  params for kernel are pushed to 0x10400 (see setup.h)
22
23    Changes:
24    Okt 25 2000 <rvdheij@iae.nl>
25	added code to skip HDR and EOF to allow SL tape IPL (5 retries)
26	changed first CCW from rewind to backspace block
27
28 */
29
30#include <linux/config.h>
31#include <asm/setup.h>
32#include <asm/lowcore.h>
33#include <asm/offsets.h>
34#include <asm/thread_info.h>
35#include <asm/page.h>
36
37#ifndef CONFIG_IPL
38        .org   0
39        .long  0x00080000,0x80000000+startup   # Just a restart PSW
40#else
41#ifdef CONFIG_IPL_TAPE
42#define IPL_BS 1024
43        .org   0
44        .long  0x00080000,0x80000000+iplstart  # The first 24 bytes are loaded
45        .long  0x27000000,0x60000001           # by ipl to addresses 0-23.
46        .long  0x02000000,0x20000000+IPL_BS    # (a PSW and two CCWs).
47        .long  0x00000000,0x00000000           # external old psw
48        .long  0x00000000,0x00000000           # svc old psw
49        .long  0x00000000,0x00000000           # program check old psw
50        .long  0x00000000,0x00000000           # machine check old psw
51        .long  0x00000000,0x00000000           # io old psw
52        .long  0x00000000,0x00000000
53        .long  0x00000000,0x00000000
54        .long  0x00000000,0x00000000
55        .long  0x000a0000,0x00000058           # external new psw
56        .long  0x000a0000,0x00000060           # svc new psw
57        .long  0x000a0000,0x00000068           # program check new psw
58        .long  0x000a0000,0x00000070           # machine check new psw
59        .long  0x00080000,0x80000000+.Lioint   # io new psw
60
61        .org   0x100
62#
63# subroutine for loading from tape
64# Paramters:
65#  R1 = device number
66#  R2 = load address
67.Lloader:
68        st    %r14,.Lldret
69        la    %r3,.Lorbread                    # r3 = address of orb
70	la    %r5,.Lirb                        # r5 = address of irb
71        st    %r2,.Lccwread+4                  # initialize CCW data addresses
72        lctl  %c6,%c6,.Lcr6
73        slr   %r2,%r2
74.Lldlp:
75        la    %r6,3                            # 3 retries
76.Lssch:
77        ssch  0(%r3)                           # load chunk of IPL_BS bytes
78        bnz   .Llderr
79.Lw4end:
80        bas   %r14,.Lwait4io
81        tm    8(%r5),0x82                      # do we have a problem ?
82        bnz   .Lrecov
83        slr   %r7,%r7
84        icm   %r7,3,10(%r5)                    # get residual count
85        lcr   %r7,%r7
86        la    %r7,IPL_BS(%r7)                  # IPL_BS-residual=#bytes read
87        ar    %r2,%r7                          # add to total size
88        tm    8(%r5),0x01                      # found a tape mark ?
89        bnz   .Ldone
90        l     %r0,.Lccwread+4                  # update CCW data addresses
91        ar    %r0,%r7
92        st    %r0,.Lccwread+4
93        b     .Lldlp
94.Ldone:
95        l     %r14,.Lldret
96        br    %r14                             # r2 contains the total size
97.Lrecov:
98        bas   %r14,.Lsense                     # do the sensing
99        bct   %r6,.Lssch                       # dec. retry count & branch
100        b     .Llderr
101#
102# Sense subroutine
103#
104.Lsense:
105        st    %r14,.Lsnsret
106        la    %r7,.Lorbsense
107        ssch  0(%r7)                           # start sense command
108        bnz   .Llderr
109        bas   %r14,.Lwait4io
110        l     %r14,.Lsnsret
111        tm    8(%r5),0x82                      # do we have a problem ?
112        bnz   .Llderr
113        br    %r14
114#
115# Wait for interrupt subroutine
116#
117.Lwait4io:
118        lpsw  .Lwaitpsw
119.Lioint:
120        c     %r1,0xb8                         # compare subchannel number
121        bne   .Lwait4io
122        tsch  0(%r5)
123        slr   %r0,%r0
124        tm    8(%r5),0x82                      # do we have a problem ?
125        bnz   .Lwtexit
126        tm    8(%r5),0x04                      # got device end ?
127        bz    .Lwait4io
128.Lwtexit:
129        br    %r14
130.Llderr:
131        lpsw  .Lcrash
132
133        .align 8
134.Lorbread:
135	.long  0x00000000,0x0080ff00,.Lccwread
136        .align 8
137.Lorbsense:
138        .long  0x00000000,0x0080ff00,.Lccwsense
139        .align 8
140.Lccwread:
141        .long  0x02200000+IPL_BS,0x00000000
142.Lccwsense:
143        .long  0x04200001,0x00000000
144.Lwaitpsw:
145	.long  0x020a0000,0x80000000+.Lioint
146
147.Lirb:	.long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
148.Lcr6:  .long  0xff000000
149        .align 8
150.Lcrash:.long  0x000a0000,0x00000000
151.Lldret:.long  0
152.Lsnsret: .long 0
153#endif  /* CONFIG_IPL_TAPE */
154
155#ifdef CONFIG_IPL_VM
156#define IPL_BS 0x730
157        .org   0
158        .long  0x00080000,0x80000000+iplstart  # The first 24 bytes are loaded
159        .long  0x02000018,0x60000050           # by ipl to addresses 0-23.
160        .long  0x02000068,0x60000050           # (a PSW and two CCWs).
161        .fill  80-24,1,0x40                    # bytes 24-79 are discarded !!
162        .long  0x020000f0,0x60000050           # The next 160 byte are loaded
163        .long  0x02000140,0x60000050           # to addresses 0x18-0xb7
164        .long  0x02000190,0x60000050           # They form the continuation
165        .long  0x020001e0,0x60000050           # of the CCW program started
166        .long  0x02000230,0x60000050           # by ipl and load the range
167        .long  0x02000280,0x60000050           # 0x0f0-0x730 from the image
168        .long  0x020002d0,0x60000050           # to the range 0x0f0-0x730
169        .long  0x02000320,0x60000050           # in memory. At the end of
170        .long  0x02000370,0x60000050           # the channel program the PSW
171        .long  0x020003c0,0x60000050           # at location 0 is loaded.
172        .long  0x02000410,0x60000050           # Initial processing starts
173        .long  0x02000460,0x60000050           # at 0xf0 = iplstart.
174        .long  0x020004b0,0x60000050
175        .long  0x02000500,0x60000050
176        .long  0x02000550,0x60000050
177        .long  0x020005a0,0x60000050
178        .long  0x020005f0,0x60000050
179        .long  0x02000640,0x60000050
180        .long  0x02000690,0x60000050
181        .long  0x020006e0,0x20000050
182
183        .org   0xf0
184#
185# subroutine for loading cards from the reader
186#
187.Lloader:
188	la    %r3,.Lorb                        # r2 = address of orb into r2
189	la    %r5,.Lirb                        # r4 = address of irb
190        la    %r6,.Lccws
191        la    %r7,20
192.Linit:
193        st    %r2,4(%r6)                       # initialize CCW data addresses
194        la    %r2,0x50(%r2)
195        la    %r6,8(%r6)
196        bct   7,.Linit
197
198        lctl  %c6,%c6,.Lcr6                    # set IO subclass mask
199	slr   %r2,%r2
200.Lldlp:
201        ssch  0(%r3)                           # load chunk of 1600 bytes
202        bnz   .Llderr
203.Lwait4irq:
204        mvc   0x78(8),.Lnewpsw                 # set up IO interrupt psw
205        lpsw  .Lwaitpsw
206.Lioint:
207        c     %r1,0xb8                         # compare subchannel number
208	bne   .Lwait4irq
209	tsch  0(%r5)
210
211	slr   %r0,%r0
212	ic    %r0,8(%r5)                       # get device status
213	chi   %r0,8                            # channel end ?
214	be    .Lcont
215	chi   %r0,12                           # channel end + device end ?
216	be    .Lcont
217
218        l     %r0,4(%r5)
219        s     %r0,8(%r3)                       # r0/8 = number of ccws executed
220        mhi   %r0,10                           # *10 = number of bytes in ccws
221        lh    %r3,10(%r5)                      # get residual count
222        sr    %r0,%r3                          # #ccws*80-residual=#bytes read
223	ar    %r2,%r0
224
225        br    %r14                             # r2 contains the total size
226
227.Lcont:
228	ahi   %r2,0x640                        # add 0x640 to total size
229        la    %r6,.Lccws
230        la    %r7,20
231.Lincr:
232        l     %r0,4(%r6)                       # update CCW data addresses
233        ahi   %r0,0x640
234        st    %r0,4(%r6)
235        ahi   %r6,8
236        bct   7,.Lincr
237
238        b     .Lldlp
239.Llderr:
240        lpsw  .Lcrash
241
242        .align 8
243.Lorb:	.long  0x00000000,0x0080ff00,.Lccws
244.Lirb:	.long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
245.Lcr6:  .long  0xff000000
246.Lloadp:.long  0,0
247        .align 8
248.Lcrash:.long  0x000a0000,0x00000000
249.Lnewpsw:
250        .long  0x00080000,0x80000000+.Lioint
251.Lwaitpsw:
252        .long  0x020a0000,0x80000000+.Lioint
253
254        .align 8
255.Lccws: .rept  19
256        .long  0x02600050,0x00000000
257        .endr
258        .long  0x02200050,0x00000000
259#endif  /* CONFIG_IPL_VM */
260
261iplstart:
262        lh    %r1,0xb8                         # test if subchannel number
263        bct   %r1,.Lnoload                     #  is valid
264	l     %r1,0xb8                         # load ipl subchannel number
265        la    %r2,IPL_BS                       # load start address
266        bas   %r14,.Lloader                    # load rest of ipl image
267        larl  %r12,_pstart                     # pointer to parameter area
268        st    %r1,IPL_DEVICE+4-PARMAREA(%r12)  # store ipl device number
269
270#
271# load parameter file from ipl device
272#
273.Lagain1:
274 	l     %r2,INITRD_START+4-PARMAREA(%r12)# use ramdisk location as temp
275        bas   %r14,.Lloader                    # load parameter file
276        ltr   %r2,%r2                          # got anything ?
277        bz    .Lnopf
278	chi   %r2,895
279	bnh   .Lnotrunc
280	la    %r2,895
281.Lnotrunc:
282	l     %r4,INITRD_START+4-PARMAREA(%r12)
283 	clc   0(3,%r4),.L_hdr		       # if it is HDRx
284 	bz    .Lagain1			       # skip dataset header
285 	clc   0(3,%r4),.L_eof		       # if it is EOFx
286 	bz    .Lagain1			       # skip dateset trailer
287        la    %r5,0(%r4,%r2)
288        lr    %r3,%r2
289.Lidebc:
290        tm    0(%r5),0x80                      # high order bit set ?
291        bo    .Ldocv                           #  yes -> convert from EBCDIC
292        ahi   %r5,-1
293        bct   %r3,.Lidebc
294        b     .Lnocv
295.Ldocv:
296        l     %r3,.Lcvtab
297        tr    0(256,%r4),0(%r3)                # convert parameters to ascii
298        tr    256(256,%r4),0(%r3)
299        tr    512(256,%r4),0(%r3)
300        tr    768(122,%r4),0(%r3)
301.Lnocv: la    %r3,COMMAND_LINE-PARMAREA(%r12)  # load adr. of command line
302	mvc   0(256,%r3),0(%r4)
303	mvc   256(256,%r3),256(%r4)
304	mvc   512(256,%r3),512(%r4)
305	mvc   768(122,%r3),768(%r4)
306        slr   %r0,%r0
307        b     .Lcntlp
308.Ldelspc:
309        ic    %r0,0(%r2,%r3)
310        chi   %r0,0x20                         # is it a space ?
311        be    .Lcntlp
312        ahi   %r2,1
313        b     .Leolp
314.Lcntlp:
315        brct  %r2,.Ldelspc
316.Leolp:
317        slr   %r0,%r0
318        stc   %r0,0(%r2,%r3)                   # terminate buffer
319.Lnopf:
320
321#
322# load ramdisk from ipl device
323#
324.Lagain2:
325 	l     %r2,INITRD_START+4-PARMAREA(%r12)# load adr. of ramdisk
326        bas   %r14,.Lloader                    # load ramdisk
327 	st    %r2,INITRD_SIZE+4-PARMAREA(%r12) # store size of ramdisk
328        ltr   %r2,%r2
329        bnz   .Lrdcont
330        st    %r2,INITRD_START+4-PARMAREA(%r12)# no ramdisk found, null it
331.Lrdcont:
332	l     %r2,INITRD_START+4-PARMAREA(%r12)
333	clc   0(3,%r2),.L_hdr		       # skip HDRx and EOFx
334	bz    .Lagain2
335	clc   0(3,%r2),.L_eof
336	bz    .Lagain2
337
338#ifdef CONFIG_IPL_VM
339#
340# reset files in VM reader
341#
342        stidp __LC_CPUID                       # store cpuid
343	tm    __LC_CPUID,0xff                  # running VM ?
344	bno   .Lnoreset
345        la    %r2,.Lreset
346        lhi   %r3,26
347        .long 0x83230008
348.Lnoreset:
349#endif
350
351#
352# everything loaded, go for it
353#
354.Lnoload:
355        l     %r1,.Lstartup
356        br    %r1
357
358.Lstartup: .long startup
359.Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
360.Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
361        .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
362        .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
363.L_eof: .long  0xc5d6c600       /* C'EOF' */
364.L_hdr: .long  0xc8c4d900       /* C'HDR' */
365#endif  /* CONFIG_IPL */
366
367#
368# SALIPL loader support. Based on a patch by Rob van der Heij.
369# This entry point is called directly from the SALIPL loader and
370# doesn't need a builtin ipl record.
371#
372        .org  0x800
373	.globl start
374start:
375	stm   %r0,%r15,0x07b0		# store registers
376	basr  %r12,%r0
377.base:
378	l     %r11,.parm
379	l     %r8,.cmd			# pointer to command buffer
380
381	ltr   %r9,%r9			# do we have SALIPL parameters?
382	bp    .sk8x8
383
384	mvc   0(64,%r8),0x00b0		# copy saved registers
385	xc    64(240-64,%r8),0(%r8)	# remainder of buffer
386	tr    0(64,%r8),.lowcase
387	b     .gotr
388.sk8x8:
389	mvc   0(240,%r8),0(%r9)		# copy iplparms into buffer
390.gotr:
391	l     %r10,.tbl			# EBCDIC to ASCII table
392	tr    0(240,%r8),0(%r10)
393	stidp __LC_CPUID		# Are we running on VM maybe
394	cli   __LC_CPUID,0xff
395	bnz   .test
396	.long 0x83300060		# diag 3,0,x'0060' - storage size
397	b     .done
398.test:
399	mvc   0x68(8),.pgmnw		# set up pgm check handler
400	l     %r2,.fourmeg
401	lr    %r3,%r2
402	bctr  %r3,%r0			# 4M-1
403.loop:  iske  %r0,%r3
404	ar    %r3,%r2
405.pgmx:
406	sr    %r3,%r2
407	la    %r3,1(%r3)
408.done:
409	l     %r1,.memsize
410	st    %r3,4(%r1)
411	slr   %r0,%r0
412	st    %r0,INITRD_SIZE+4-PARMAREA(%r11)
413	st    %r0,INITRD_START+4-PARMAREA(%r11)
414	j     startup                   # continue with startup
415.tbl:	.long _ebcasc			# translate table
416.cmd:	.long COMMAND_LINE		# address of command line buffer
417.parm:	.long PARMAREA
418.fourmeg: .long 0x00400000      	# 4M
419.pgmnw:	.long 0x00080000,.pgmx
420.memsize: .long memory_size
421.lowcase:
422	.byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07
423	.byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
424	.byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17
425	.byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
426	.byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27
427	.byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
428	.byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37
429	.byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
430	.byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47
431	.byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
432	.byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57
433	.byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
434	.byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67
435	.byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
436	.byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77
437	.byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f
438
439	.byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87
440	.byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
441	.byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97
442	.byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
443	.byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7
444	.byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
445	.byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7
446	.byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
447	.byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87	# .abcdefg
448	.byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf	# hi
449	.byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97 	# .jklmnop
450	.byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf	# qr
451	.byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7	# ..stuvwx
452	.byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef	# yz
453	.byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7
454	.byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
455
456#
457# startup-code at 0x10000, running in real mode
458# this is called either by the ipl loader or directly by PSW restart
459# or linload or SALIPL
460#
461        .org  0x10000
462startup:basr  %r13,0                     # get base
463.LPG1:  sll   %r13,1                     # remove high order bit
464        srl   %r13,1
465        lhi   %r1,1                      # mode 1 = esame
466        slr   %r0,%r0                    # set cpuid to zero
467        sigp  %r1,%r0,0x12               # switch to esame mode
468	sam64				 # switch to 64 bit mode
469	lctlg %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
470	larl  %r12,_pstart               # pointer to parameter area
471					 # move IPL device to lowcore
472        mvc   __LC_IPLDEV(4),IPL_DEVICE+4-PARMAREA(%r12)
473
474#
475# clear bss memory
476#
477	larl  %r2,__bss_start           # start of bss segment
478        larl  %r3,_end                  # end of bss segment
479        sgr   %r3,%r2                   # length of bss
480        sgr   %r4,%r4                   #
481        sgr   %r5,%r5                   # set src,length and pad to zero
482        mvcle %r2,%r4,0                 # clear mem
483        jo    .-4                       # branch back, if not finish
484
485	l     %r2,.Lrcp-.LPG1(%r13)	# Read SCP forced command word
486.Lservicecall:
487	stosm .Lpmask-.LPG1(%r13),0x01	# authorize ext interrupts
488
489	stctg %r0,%r0,.Lcr-.LPG1(%r13)	# get cr0
490	la    %r1,0x200			# set bit 22
491	og    %r1,.Lcr-.LPG1(%r13)	# or old cr0 with r1
492	stg   %r1,.Lcr-.LPG1(%r13)
493	lctlg %r0,%r0,.Lcr-.LPG1(%r13)	# load modified cr0
494
495	mvc   __LC_EXT_NEW_PSW(8),.Lpcmsk-.LPG1(%r13) # set postcall psw
496	larl  %r1,.Lsclph
497	stg   %r1,__LC_EXT_NEW_PSW+8	# set handler
498
499	larl  %r4,_pstart		# %r4 is our index for sccb stuff
500	la    %r1,.Lsccb-PARMAREA(%r4)	# our sccb
501	.insn rre,0xb2200000,%r2,%r1	# service call
502	ipm   %r1
503	srl   %r1,28			# get cc code
504	xr    %r3,%r3
505	chi   %r1,3
506	be    .Lfchunk-.LPG1(%r13)	# leave
507	chi   %r1,2
508	be    .Lservicecall-.LPG1(%r13)
509	lpsw  .Lwaitsclp-.LPG1(%r13)
510.Lsclph:
511	lh    %r1,.Lsccbr-PARMAREA(%r4)
512	chi   %r1,0x10			# 0x0010 is the sucess code
513	je    .Lprocsccb		# let's process the sccb
514	chi   %r1,0x1f0
515	bne   .Lfchunk-.LPG1(%r13)	# unhandled error code
516	c     %r2,.Lrcp-.LPG1(%r13)	# Did we try Read SCP forced
517	bne   .Lfchunk-.LPG1(%r13)	# if no, give up
518	l     %r2,.Lrcp2-.LPG1(%r13)	# try with Read SCP
519	b     .Lservicecall-.LPG1(%r13)
520.Lprocsccb:
521	lh    %r1,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
522	chi   %r1,0x00
523	jne   .Lscnd
524	lg    %r1,.Lscpincr2-PARMAREA(%r4) # otherwise use this one
525.Lscnd:
526	xr    %r3,%r3			# same logic
527	ic    %r3,.Lscpa1-PARMAREA(%r4)
528	chi   %r3,0x00
529	jne   .Lcompmem
530	l     %r3,.Lscpa2-PARMAREA(%r13)
531.Lcompmem:
532	mlgr  %r2,%r1			# mem in MB on 128-bit
533	l     %r1,.Lonemb-.LPG1(%r13)
534	mlgr  %r2,%r1			# mem size in bytes in %r3
535	b     .Lfchunk-.LPG1(%r13)
536
537.Lpmask:
538	.byte 0
539	.align 8
540.Lcr:
541	.quad 0x00  # place holder for cr0
542.Lwaitsclp:
543	.long 0x020A0000
544	.quad .Lsclph
545.Lrcp:
546	.int 0x00120001 # Read SCP forced code
547.Lrcp2:
548	.int 0x00020001 # Read SCP code
549.Lonemb:
550	.int 0x100000
551
552.Lfchunk:
553					 # set program check new psw mask
554	mvc   __LC_PGM_NEW_PSW(8),.Lpcmsk-.LPG1(%r13)
555
556#
557# find memory chunks.
558#
559	lgr   %r9,%r3			 # end of mem
560	larl  %r1,.Lchkmem               # set program check address
561	stg   %r1,__LC_PGM_NEW_PSW+8
562	la    %r1,1                      # test in increments of 128KB
563	sllg  %r1,%r1,17
564	larl  %r3,memory_chunk
565	slgr  %r4,%r4                    # set start of chunk to zero
566	slgr  %r5,%r5                    # set end of chunk to zero
567	slr  %r6,%r6			 # set access code to zero
568	la    %r10,MEMORY_CHUNKS	 # number of chunks
569.Lloop:
570	tprot 0(%r5),0			 # test protection of first byte
571	ipm   %r7
572	srl   %r7,28
573	clr   %r6,%r7			 # compare cc with last access code
574	je    .Lsame
575	j     .Lchkmem
576.Lsame:
577	algr  %r5,%r1			 # add 128KB to end of chunk
578					 # no need to check here,
579	brc   12,.Lloop			 # this is the same chunk
580.Lchkmem:				 # > 16EB or tprot got a program check
581	clgr  %r4,%r5			 # chunk size > 0?
582	je    .Lchkloop
583	stg   %r4,0(%r3)		 # store start address of chunk
584	lgr   %r0,%r5
585	slgr  %r0,%r4
586	stg   %r0,8(%r3)		 # store size of chunk
587	st    %r6,20(%r3)		 # store type of chunk
588	la    %r3,24(%r3)
589	larl  %r8,memory_size
590	stg   %r5,0(%r8)                 # store memory size
591	ahi   %r10,-1			 # update chunk number
592.Lchkloop:
593	lr    %r6,%r7			 # set access code to last cc
594	# we got an exception or we're starting a new
595	# chunk , we must check if we should
596	# still try to find valid memory (if we detected
597	# the amount of available storage), and if we
598	# have chunks left
599	lghi  %r4,1
600	sllg  %r4,%r4,31
601	clgr  %r5,%r4
602	je    .Lhsaskip
603	xr    %r0, %r0
604	clgr  %r0, %r9			 # did we detect memory?
605	je    .Ldonemem			 # if not, leave
606	chi   %r10, 0			 # do we have chunks left?
607	je    .Ldonemem
608.Lhsaskip:
609	algr  %r5,%r1			 # add 128KB to end of chunk
610	lgr   %r4,%r5			 # potential new chunk
611	clgr  %r5,%r9			 # should we go on?
612	jl    .Lloop
613.Ldonemem:
614
615	larl  %r12,machine_flags
616#
617# find out if we are running under VM
618#
619        stidp  __LC_CPUID               # store cpuid
620	tm     __LC_CPUID,0xff          # running under VM ?
621	bno    0f-.LPG1(%r13)
622        oi     7(%r12),1                # set VM flag
6230:      lh     %r0,__LC_CPUID+4         # get cpu version
624        chi    %r0,0x7490               # running on a P/390 ?
625        bne    1f-.LPG1(%r13)
626        oi     7(%r12),4                # set P/390 flag
6271:
628
629#
630# find out if we have the MVPG instruction
631#
632	la     %r1,0f-.LPG1(%r13)       # set program check address
633	stg    %r1,__LC_PGM_NEW_PSW+8
634	sgr    %r0,%r0
635	lghi   %r1,0
636	lghi   %r2,0
637	mvpg   %r1,%r2                  # test MVPG instruction
638	oi     7(%r12),16               # set MVPG flag
6390:
640
641#
642# find out if the diag 0x44 works in 64 bit mode
643#
644	la     %r1,0f-.LPG1(%r13)	# set program check address
645	stg    %r1,__LC_PGM_NEW_PSW+8
646	mvc    __LC_DIAG44_OPCODE(8),.Lnop-.LPG1(%r13)
647	diag   0,0,0x44			# test diag 0x44
648	oi     7(%r12),32		# set diag44 flag
649	mvc    __LC_DIAG44_OPCODE(8),.Ldiag44-.LPG1(%r13)
6500:
651
652#
653# find out if we have the IDTE instruction
654#
655	la     %r1,0f-.LPG1(%r13)	# set program check address
656	stg    %r1,__LC_PGM_NEW_PSW+8
657	.long	0xb2b10000		# store facility list
658	tm	0xc8,0x08		# check bit for clearing-by-ASCE
659	bno	0f-.LPG1(%r13)
660	lhi	%r1,2094
661	lhi	%r2,0
662	.long	0xb98e2001
663	oi	7(%r12),0x80		# set IDTE flag
6640:
665
666        lpswe .Lentry-.LPG1(13)         # jump to _stext in primary-space,
667                                        # virtual and never return ...
668        .align 16
669.Lentry:.quad  0x0000000180000000,_stext
670.Lctl:  .quad  0x04b50002               # cr0: various things
671        .quad  0                        # cr1: primary space segment table
672        .quad  .Lduct                   # cr2: dispatchable unit control table
673        .quad  0                        # cr3: instruction authorization
674        .quad  0                        # cr4: instruction authorization
675        .quad  0xffffffffffffffff       # cr5: primary-aste origin
676        .quad  0                        # cr6:  I/O interrupts
677        .quad  0                        # cr7:  secondary space segment table
678        .quad  0                        # cr8:  access registers translation
679        .quad  0                        # cr9:  tracing off
680        .quad  0                        # cr10: tracing off
681        .quad  0                        # cr11: tracing off
682        .quad  0                        # cr12: tracing off
683        .quad  0                        # cr13: home space segment table
684        .quad  0xc0000000               # cr14: machine check handling off
685        .quad  0                        # cr15: linkage stack operations
686.Lpcmsk:.quad  0x0000000180000000
687.L4malign:.quad 0xffffffffffc00000
688.Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8
689.Lnop:	.long  0x07000700
690.Ldiag44:.long 0x83000044
691
692	.org PARMAREA-64
693.Lduct:	.long 0,0,0,0,0,0,0,0
694	.long 0,0,0,0,0,0,0,0
695
696#
697# params at 10400 (setup.h)
698#
699	.org   PARMAREA
700	.global _pstart
701_pstart:
702	.quad  0                        # IPL_DEVICE
703        .quad  RAMDISK_ORIGIN           # INITRD_START
704        .quad  RAMDISK_SIZE             # INITRD_SIZE
705
706        .org   COMMAND_LINE
707    	.byte  "root=/dev/ram0 ro"
708        .byte  0
709	.org   0x11000
710.Lsccb:
711	.hword 0x1000			# length, one page
712	.byte 0x00,0x00,0x00
713	.byte 0x80			# variable response bit set
714.Lsccbr:
715	.hword 0x00			# response code
716.Lscpincr1:
717	.hword 0x00
718.Lscpa1:
719	.byte 0x00
720	.fill 89,1,0
721.Lscpa2:
722	.int 0x00
723.Lscpincr2:
724	.quad 0x00
725	.fill 3984,1,0
726	.org 0x12000
727	.global _pend
728_pend:
729
730#ifdef CONFIG_SHARED_KERNEL
731	.org   0x100000
732#endif
733
734#
735# startup-code, running in virtual mode
736#
737        .globl _stext
738_stext:	basr  %r13,0                    # get base
739.LPG2:
740#
741# Setup stack
742#
743	larl  %r15,init_thread_union
744	lg    %r14,__TI_task(%r15)      # cache current in lowcore
745	stg   %r14,__LC_CURRENT
746        aghi  %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
747        stg   %r15,__LC_KERNEL_STACK    # set end of kernel stack
748        aghi  %r15,-160
749        xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
750
751# check control registers
752        stctg  %c0,%c15,0(%r15)
753	oi     6(%r15),0x20             # enable sigp external interrupts
754	oi     4(%r15),0x10             # switch on low address proctection
755        lctlg  %c0,%c15,0(%r15)
756
757#
758        lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
759        brasl  %r14,start_kernel        # go to C code
760#
761# We returned from start_kernel ?!? PANIK
762#
763        basr  %r13,0
764	lpswe .Ldw-.(%r13)           # load disabled wait psw
765#
766            .align 8
767.Ldw:       .quad  0x0002000180000000,0x0000000000000000
768.Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
769
770