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
34#ifndef CONFIG_IPL
35        .org   0
36        .long  0x00080000,0x80000000+startup   # Just a restart PSW
37#else
38#ifdef CONFIG_IPL_TAPE
39#define IPL_BS 1024
40        .org   0
41        .long  0x00080000,0x80000000+iplstart  # The first 24 bytes are loaded
42        .long  0x27000000,0x60000001           # by ipl to addresses 0-23.
43        .long  0x02000000,0x20000000+IPL_BS    # (a PSW and two CCWs).
44        .long  0x00000000,0x00000000           # external old psw
45        .long  0x00000000,0x00000000           # svc old psw
46        .long  0x00000000,0x00000000           # program check old psw
47        .long  0x00000000,0x00000000           # machine check old psw
48        .long  0x00000000,0x00000000           # io old psw
49        .long  0x00000000,0x00000000
50        .long  0x00000000,0x00000000
51        .long  0x00000000,0x00000000
52        .long  0x000a0000,0x00000058           # external new psw
53        .long  0x000a0000,0x00000060           # svc new psw
54        .long  0x000a0000,0x00000068           # program check new psw
55        .long  0x000a0000,0x00000070           # machine check new psw
56        .long  0x00080000,0x80000000+.Lioint   # io new psw
57
58        .org   0x100
59#
60# subroutine for loading from tape
61# Paramters:
62#  R1 = device number
63#  R2 = load address
64.Lloader:
65        st    %r14,.Lldret
66        la    %r3,.Lorbread                    # r3 = address of orb
67	la    %r5,.Lirb                        # r5 = address of irb
68        st    %r2,.Lccwread+4                  # initialize CCW data addresses
69        lctl  %c6,%c6,.Lcr6
70        slr   %r2,%r2
71.Lldlp:
72        la    %r6,3                            # 3 retries
73.Lssch:
74        ssch  0(%r3)                           # load chunk of IPL_BS bytes
75        bnz   .Llderr
76.Lw4end:
77        bas   %r14,.Lwait4io
78        tm    8(%r5),0x82                      # do we have a problem ?
79        bnz   .Lrecov
80        slr   %r7,%r7
81        icm   %r7,3,10(%r5)                    # get residual count
82        lcr   %r7,%r7
83        la    %r7,IPL_BS(%r7)                  # IPL_BS-residual=#bytes read
84        ar    %r2,%r7                          # add to total size
85        tm    8(%r5),0x01                      # found a tape mark ?
86        bnz   .Ldone
87        l     %r0,.Lccwread+4                  # update CCW data addresses
88        ar    %r0,%r7
89        st    %r0,.Lccwread+4
90        b     .Lldlp
91.Ldone:
92        l     %r14,.Lldret
93        br    %r14                             # r2 contains the total size
94.Lrecov:
95        bas   %r14,.Lsense                     # do the sensing
96        bct   %r6,.Lssch                       # dec. retry count & branch
97        b     .Llderr
98#
99# Sense subroutine
100#
101.Lsense:
102        st    %r14,.Lsnsret
103        la    %r7,.Lorbsense
104        ssch  0(%r7)                           # start sense command
105        bnz   .Llderr
106        bas   %r14,.Lwait4io
107        l     %r14,.Lsnsret
108        tm    8(%r5),0x82                      # do we have a problem ?
109        bnz   .Llderr
110        br    %r14
111#
112# Wait for interrupt subroutine
113#
114.Lwait4io:
115        lpsw  .Lwaitpsw
116.Lioint:
117        c     %r1,0xb8                         # compare subchannel number
118        bne   .Lwait4io
119        tsch  0(%r5)
120        slr   %r0,%r0
121        tm    8(%r5),0x82                      # do we have a problem ?
122        bnz   .Lwtexit
123        tm    8(%r5),0x04                      # got device end ?
124        bz    .Lwait4io
125.Lwtexit:
126        br    %r14
127.Llderr:
128        lpsw  .Lcrash
129
130        .align 8
131.Lorbread:
132	.long  0x00000000,0x0080ff00,.Lccwread
133        .align 8
134.Lorbsense:
135        .long  0x00000000,0x0080ff00,.Lccwsense
136        .align 8
137.Lccwread:
138        .long  0x02200000+IPL_BS,0x00000000
139.Lccwsense:
140        .long  0x04200001,0x00000000
141.Lwaitpsw:
142	.long  0x020a0000,0x80000000+.Lioint
143
144.Lirb:	.long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
145.Lcr6:  .long  0xff000000
146        .align 8
147.Lcrash:.long  0x000a0000,0x00000000
148.Lldret:.long  0
149.Lsnsret: .long 0
150#endif  /* CONFIG_IPL_TAPE */
151
152#ifdef CONFIG_IPL_VM
153#define IPL_BS 0x730
154        .org   0
155        .long  0x00080000,0x80000000+iplstart  # The first 24 bytes are loaded
156        .long  0x02000018,0x60000050           # by ipl to addresses 0-23.
157        .long  0x02000068,0x60000050           # (a PSW and two CCWs).
158        .fill  80-24,1,0x40                    # bytes 24-79 are discarded !!
159        .long  0x020000f0,0x60000050           # The next 160 byte are loaded
160        .long  0x02000140,0x60000050           # to addresses 0x18-0xb7
161        .long  0x02000190,0x60000050           # They form the continuation
162        .long  0x020001e0,0x60000050           # of the CCW program started
163        .long  0x02000230,0x60000050           # by ipl and load the range
164        .long  0x02000280,0x60000050           # 0x0f0-0x730 from the image
165        .long  0x020002d0,0x60000050           # to the range 0x0f0-0x730
166        .long  0x02000320,0x60000050           # in memory. At the end of
167        .long  0x02000370,0x60000050           # the channel program the PSW
168        .long  0x020003c0,0x60000050           # at location 0 is loaded.
169        .long  0x02000410,0x60000050           # Initial processing starts
170        .long  0x02000460,0x60000050           # at 0xf0 = iplstart.
171        .long  0x020004b0,0x60000050
172        .long  0x02000500,0x60000050
173        .long  0x02000550,0x60000050
174        .long  0x020005a0,0x60000050
175        .long  0x020005f0,0x60000050
176        .long  0x02000640,0x60000050
177        .long  0x02000690,0x60000050
178        .long  0x020006e0,0x20000050
179
180        .org   0xf0
181#
182# subroutine for loading cards from the reader
183#
184.Lloader:
185	la    %r3,.Lorb                        # r2 = address of orb into r2
186	la    %r5,.Lirb                        # r4 = address of irb
187        la    %r6,.Lccws
188        la    %r7,20
189.Linit:
190        st    %r2,4(%r6)                       # initialize CCW data addresses
191        la    %r2,0x50(%r2)
192        la    %r6,8(%r6)
193        bct   7,.Linit
194
195        lctl  %c6,%c6,.Lcr6                    # set IO subclass mask
196	slr   %r2,%r2
197.Lldlp:
198        ssch  0(%r3)                           # load chunk of 1600 bytes
199        bnz   .Llderr
200.Lwait4irq:
201        mvc   0x78(8),.Lnewpsw                 # set up IO interrupt psw
202        lpsw  .Lwaitpsw
203.Lioint:
204        c     %r1,0xb8                         # compare subchannel number
205	bne   .Lwait4irq
206	tsch  0(%r5)
207
208	slr   %r0,%r0
209	ic    %r0,8(%r5)                       # get device status
210	chi   %r0,8                            # channel end ?
211	be    .Lcont
212	chi   %r0,12                           # channel end + device end ?
213	be    .Lcont
214
215        l     %r0,4(%r5)
216        s     %r0,8(%r3)                       # r0/8 = number of ccws executed
217        mhi   %r0,10                           # *10 = number of bytes in ccws
218        lh    %r3,10(%r5)                      # get residual count
219        sr    %r0,%r3                          # #ccws*80-residual=#bytes read
220	ar    %r2,%r0
221
222        br    %r14                             # r2 contains the total size
223
224.Lcont:
225	ahi   %r2,0x640                        # add 0x640 to total size
226        la    %r6,.Lccws
227        la    %r7,20
228.Lincr:
229        l     %r0,4(%r6)                       # update CCW data addresses
230        ahi   %r0,0x640
231        st    %r0,4(%r6)
232        ahi   %r6,8
233        bct   7,.Lincr
234
235        b     .Lldlp
236.Llderr:
237        lpsw  .Lcrash
238
239        .align 8
240.Lorb:	.long  0x00000000,0x0080ff00,.Lccws
241.Lirb:	.long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
242.Lcr6:  .long  0xff000000
243.Lloadp:.long  0,0
244        .align 8
245.Lcrash:.long  0x000a0000,0x00000000
246.Lnewpsw:
247        .long  0x00080000,0x80000000+.Lioint
248.Lwaitpsw:
249        .long  0x020a0000,0x80000000+.Lioint
250
251        .align 8
252.Lccws: .rept  19
253        .long  0x02600050,0x00000000
254        .endr
255        .long  0x02200050,0x00000000
256#endif  /* CONFIG_IPL_VM */
257
258iplstart:
259        lh    %r1,0xb8                         # test if subchannel number
260        bct   %r1,.Lnoload                     #  is valid
261	l     %r1,0xb8                         # load ipl subchannel number
262        la    %r2,IPL_BS                       # load start address
263        bas   %r14,.Lloader                    # load rest of ipl image
264        larl  %r12,_pstart                     # pointer to parameter area
265        st    %r1,IPL_DEVICE+4-PARMAREA(%r12)  # store ipl device number
266
267#
268# load parameter file from ipl device
269#
270.Lagain1:
271 	l     %r2,INITRD_START+4-PARMAREA(%r12)# use ramdisk location as temp
272        bas   %r14,.Lloader                    # load parameter file
273        ltr   %r2,%r2                          # got anything ?
274        bz    .Lnopf
275	chi   %r2,895
276	bnh   .Lnotrunc
277	la    %r2,895
278.Lnotrunc:
279	l     %r4,INITRD_START+4-PARMAREA(%r12)
280 	clc   0(3,%r4),.L_hdr		       # if it is HDRx
281 	bz    .Lagain1			       # skip dataset header
282 	clc   0(3,%r4),.L_eof		       # if it is EOFx
283 	bz    .Lagain1			       # skip dateset trailer
284        la    %r5,0(%r4,%r2)
285        lr    %r3,%r2
286.Lidebc:
287        tm    0(%r5),0x80                      # high order bit set ?
288        bo    .Ldocv                           #  yes -> convert from EBCDIC
289        ahi   %r5,-1
290        bct   %r3,.Lidebc
291        b     .Lnocv
292.Ldocv:
293        l     %r3,.Lcvtab
294        tr    0(256,%r4),0(%r3)                # convert parameters to ascii
295        tr    256(256,%r4),0(%r3)
296        tr    512(256,%r4),0(%r3)
297        tr    768(122,%r4),0(%r3)
298.Lnocv: la    %r3,COMMAND_LINE-PARMAREA(%r12)  # load adr. of command line
299	mvc   0(256,%r3),0(%r4)
300	mvc   256(256,%r3),256(%r4)
301	mvc   512(256,%r3),512(%r4)
302	mvc   768(122,%r3),768(%r4)
303        slr   %r0,%r0
304        b     .Lcntlp
305.Ldelspc:
306        ic    %r0,0(%r2,%r3)
307        chi   %r0,0x20                         # is it a space ?
308        be    .Lcntlp
309        ahi   %r2,1
310        b     .Leolp
311.Lcntlp:
312        brct  %r2,.Ldelspc
313.Leolp:
314        slr   %r0,%r0
315        stc   %r0,0(%r2,%r3)                   # terminate buffer
316.Lnopf:
317
318#
319# load ramdisk from ipl device
320#
321.Lagain2:
322 	l     %r2,INITRD_START+4-PARMAREA(%r12)# load adr. of ramdisk
323        bas   %r14,.Lloader                    # load ramdisk
324 	st    %r2,INITRD_SIZE+4-PARMAREA(%r12) # store size of ramdisk
325        ltr   %r2,%r2
326        bnz   .Lrdcont
327        st    %r2,INITRD_START+4-PARMAREA(%r12)# no ramdisk found, null it
328.Lrdcont:
329	l     %r2,INITRD_START+4-PARMAREA(%r12)
330	clc   0(3,%r2),.L_hdr		       # skip HDRx and EOFx
331	bz    .Lagain2
332	clc   0(3,%r2),.L_eof
333	bz    .Lagain2
334
335#ifdef CONFIG_IPL_VM
336#
337# reset files in VM reader
338#
339        stidp __LC_CPUID                       # store cpuid
340	tm    __LC_CPUID,0xff                  # running VM ?
341	bno   .Lnoreset
342        la    %r2,.Lreset
343        lhi   %r3,26
344        .long 0x83230008
345.Lnoreset:
346#endif
347
348#
349# everything loaded, go for it
350#
351.Lnoload:
352        l     %r1,.Lstartup
353        br    %r1
354
355.Lstartup: .long startup
356.Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
357.Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
358        .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
359        .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
360.L_eof: .long  0xc5d6c600       /* C'EOF' */
361.L_hdr: .long  0xc8c4d900       /* C'HDR' */
362#endif  /* CONFIG_IPL */
363
364#
365# SALIPL loader support. Based on a patch by Rob van der Heij.
366# This entry point is called directly from the SALIPL loader and
367# doesn't need a builtin ipl record.
368#
369        .org  0x800
370	.globl start
371start:
372	stm   %r0,%r15,0x07b0		# store registers
373	basr  %r12,%r0
374.base:
375	l     %r11,.parm
376	l     %r8,.cmd			# pointer to command buffer
377
378	ltr   %r9,%r9			# do we have SALIPL parameters?
379	bp    .sk8x8
380
381	mvc   0(64,%r8),0x00b0		# copy saved registers
382	xc    64(240-64,%r8),0(%r8)	# remainder of buffer
383	tr    0(64,%r8),.lowcase
384	b     .gotr
385.sk8x8:
386	mvc   0(240,%r8),0(%r9)		# copy iplparms into buffer
387.gotr:
388	l     %r10,.tbl			# EBCDIC to ASCII table
389	tr    0(240,%r8),0(%r10)
390	stidp __LC_CPUID		# Are we running on VM maybe
391	cli   __LC_CPUID,0xff
392	bnz   .test
393	.long 0x83300060		# diag 3,0,x'0060' - storage size
394	b     .done
395.test:
396	mvc   0x68(8),.pgmnw		# set up pgm check handler
397	l     %r2,.fourmeg
398	lr    %r3,%r2
399	bctr  %r3,%r0			# 4M-1
400.loop:  iske  %r0,%r3
401	ar    %r3,%r2
402.pgmx:
403	sr    %r3,%r2
404	la    %r3,1(%r3)
405.done:
406	l     %r1,.memsize
407	st    %r3,4(%r1)
408	slr   %r0,%r0
409	st    %r0,INITRD_SIZE+4-PARMAREA(%r11)
410	st    %r0,INITRD_START+4-PARMAREA(%r11)
411	j     startup                   # continue with startup
412.tbl:	.long _ebcasc			# translate table
413.cmd:	.long COMMAND_LINE		# address of command line buffer
414.parm:	.long PARMAREA
415.fourmeg: .long 0x00400000      	# 4M
416.pgmnw:	.long 0x00080000,.pgmx
417.memsize: .long memory_size
418.lowcase:
419	.byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07
420	.byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
421	.byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17
422	.byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
423	.byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27
424	.byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
425	.byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37
426	.byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
427	.byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47
428	.byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
429	.byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57
430	.byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
431	.byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67
432	.byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
433	.byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77
434	.byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f
435
436	.byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87
437	.byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
438	.byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97
439	.byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
440	.byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7
441	.byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
442	.byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7
443	.byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
444	.byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87	# .abcdefg
445	.byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf	# hi
446	.byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97 	# .jklmnop
447	.byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf	# qr
448	.byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7	# ..stuvwx
449	.byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef	# yz
450	.byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7
451	.byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
452
453#
454# startup-code at 0x10000, running in real mode
455# this is called either by the ipl loader or directly by PSW restart
456# or linload or SALIPL
457#
458        .org  0x10000
459startup:basr  %r13,0                     # get base
460.LPG1:  sll   %r13,1                     # remove high order bit
461        srl   %r13,1
462        lhi   %r1,1                      # mode 1 = esame
463        slr   %r0,%r0                    # set cpuid to zero
464        sigp  %r1,%r0,0x12               # switch to esame mode
465	sam64				 # switch to 64 bit mode
466	lctlg %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
467	larl  %r12,_pstart               # pointer to parameter area
468					 # move IPL device to lowcore
469        mvc   __LC_IPLDEV(4),IPL_DEVICE+4-PARMAREA(%r12)
470
471#
472# clear bss memory
473#
474	larl  %r2,__bss_start           # start of bss segment
475        larl  %r3,_end                  # end of bss segment
476        sgr   %r3,%r2                   # length of bss
477        sgr   %r4,%r4                   #
478        sgr   %r5,%r5                   # set src,length and pad to zero
479        mvcle %r2,%r4,0                 # clear mem
480        jo    .-4                       # branch back, if not finish
481
482					 # set program check new psw mask
483	mvc   __LC_PGM_NEW_PSW(8),.Lpcmsk-.LPG1(%r13)
484
485#
486# find memory chunks.
487#
488	larl  %r1,.Lchkmem               # set program check address
489	stg   %r1,__LC_PGM_NEW_PSW+8
490	la    %r1,1                      # test in increments of 128KB
491	sllg  %r1,%r1,17
492	larl  %r3,memory_chunk
493	slgr  %r4,%r4                    # set start of chunk to zero
494	slgr  %r5,%r5                    # set end of chunk to zero
495	slr  %r6,%r6			 # set access code to zero
496.Lloop:
497	tprot 0(%r5),0			 # test protection of first byte
498	ipm   %r7
499	srl   %r7,28
500	clr   %r6,%r7			 # compare cc with last access code
501	je    .Lsame
502	clgr  %r4,%r5			 # chunk size > 0?
503	je    .Lsize0
504	stg   %r4,0(%r3)		 # store start address of chunk
505	lgr   %r0,%r5
506	slgr  %r0,%r4
507	stg   %r0,8(%r3)		 # store size of chunk
508	st    %r6,20(%r3)		 # store type of chunk
509	la    %r3,24(%r3)
510	lgr   %r4,%r5			 # set start to end
511	larl  %r8,memory_size
512	stg   %r5,0(%r8)                 # store memory size
513.Lsize0:
514	lr    %r6,%r7			 # set access code to last cc
515.Lsame:
516	algr  %r5,%r1			 # add 128KB to end of chunk
517	brc   12,.Lloop
518.Lchkmem:				 # > 16EB or tprot got a program check
519	clgr  %r4,%r5			 # chunk size > 0?
520	je    .Ldonemem
521	stg   %r4,0(%r3)		 # store start address of chunk
522	lgr   %r0,%r5
523	slgr  %r0,%r4
524	stg   %r0,8(%r3)		 # store size of chunk
525	st    %r6,20(%r3)		 # store type of chunk
526	la    %r3,24(%r3)
527	lgr   %r4,%r5
528	larl  %r8,memory_size
529	stg   %r5,0(%r8)                 # store memory size
530#
531# Running native the HSA is located at 2GB and we will get an
532# addressing exception trying to access it. We have to restart
533# the scan at 2GB to find out if the machine has more than 2GB.
534#
535	lghi  %r4,1
536	sllg  %r4,%r4,31
537	clgr  %r5,%r4
538	jhe   .Ldonemem
539	lgr   %r5,%r4
540	j     .Lloop
541.Ldonemem:
542
543	larl  %r12,machine_flags
544#
545# find out if we are running under VM
546#
547        stidp  __LC_CPUID               # store cpuid
548	tm     __LC_CPUID,0xff          # running under VM ?
549	bno    0f-.LPG1(%r13)
550        oi     7(%r12),1                # set VM flag
5510:      lh     %r0,__LC_CPUID+4         # get cpu version
552        chi    %r0,0x7490               # running on a P/390 ?
553        bne    1f-.LPG1(%r13)
554        oi     7(%r12),4                # set P/390 flag
5551:
556	chi    %r0,0x2084		# new stidp format?
557	bne    2f-.LPG1(%r13)
558	oi     7(%r12),64		# set new stidp flag
5592:
560
561#
562# find out if we have the MVPG instruction
563#
564	la     %r1,0f-.LPG1(%r13)       # set program check address
565	stg    %r1,__LC_PGM_NEW_PSW+8
566	sgr    %r0,%r0
567	lghi   %r1,0
568	lghi   %r2,0
569	mvpg   %r1,%r2                  # test MVPG instruction
570	oi     7(%r12),16               # set MVPG flag
5710:
572
573#
574# find out if the diag 0x44 works in 64 bit mode
575#
576	la     %r1,0f-.LPG1(%r13)	# set program check address
577	stg    %r1,__LC_PGM_NEW_PSW+8
578	mvc    __LC_DIAG44_OPCODE(8),.Lnop-.LPG1(%r13)
579	diag   0,0,0x44			# test diag 0x44
580	oi     7(%r12),32		# set diag44 flag
581	mvc    __LC_DIAG44_OPCODE(8),.Ldiag44-.LPG1(%r13)
5820:
583
584        lpswe .Lentry-.LPG1(13)         # jump to _stext in primary-space,
585                                        # virtual and never return ...
586        .align 16
587.Lentry:.quad  0x0000000180000000,_stext
588.Lctl:  .quad  0x04b50002               # cr0: various things
589        .quad  0                        # cr1: primary space segment table
590        .quad  .Lduct                   # cr2: dispatchable unit control table
591        .quad  0                        # cr3: instruction authorization
592        .quad  0                        # cr4: instruction authorization
593        .quad  0xffffffffffffffff       # cr5: primary-aste origin
594        .quad  0                        # cr6:  I/O interrupts
595        .quad  0                        # cr7:  secondary space segment table
596        .quad  0                        # cr8:  access registers translation
597        .quad  0                        # cr9:  tracing off
598        .quad  0                        # cr10: tracing off
599        .quad  0                        # cr11: tracing off
600        .quad  0                        # cr12: tracing off
601        .quad  0                        # cr13: home space segment table
602        .quad  0xc0000000               # cr14: machine check handling off
603        .quad  0                        # cr15: linkage stack operations
604.Lpcmsk:.quad  0x0000000180000000
605.L4malign:.quad 0xffffffffffc00000
606.Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8
607.Lnop:	.long  0x07000700
608.Ldiag44:.long 0x83000044
609
610	.org PARMAREA-64
611.Lduct:	.long 0,0,0,0,0,0,0,0
612	.long 0,0,0,0,0,0,0,0
613
614#
615# params at 10400 (setup.h)
616#
617	.org   PARMAREA
618	.global _pstart
619_pstart:
620	.quad  0                        # IPL_DEVICE
621        .quad  RAMDISK_ORIGIN           # INITRD_START
622        .quad  RAMDISK_SIZE             # INITRD_SIZE
623
624        .org   COMMAND_LINE
625    	.byte  "root=/dev/ram0 ro"
626        .byte  0
627	.org   0x11000
628	.global _pend
629_pend:
630
631#ifdef CONFIG_SHARED_KERNEL
632	.org   0x100000
633#endif
634
635#
636# startup-code, running in virtual mode
637#
638        .globl _stext
639_stext:	basr  %r13,0                    # get base
640.LPG2:
641#
642# Setup stack
643#
644	larl  %r15,init_task_union
645        aghi  %r15,16384                # init_task_union + 16384
646        stg   %r15,__LC_KERNEL_STACK    # set end of kernel stack
647        aghi  %r15,-160
648        xc    0(8,%r15),0(%r15)         # set backchain to zero
649
650# check control registers
651        stctg  %c0,%c15,0(%r15)
652	oi     6(%r15),0x20             # enable sigp external interrupts
653	oi     4(%r15),0x10             # switch on low address proctection
654        lctlg  %c0,%c15,0(%r15)
655
656#
657        lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
658        brasl  %r14,start_kernel        # go to C code
659#
660# We returned from start_kernel ?!? PANIK
661#
662        basr  %r13,0
663	lpswe .Ldw-.(%r13)           # load disabled wait psw
664#
665            .align 8
666.Ldw:       .quad  0x0002000180000000,0x0000000000000000
667.Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
668
669