xref: /linux/arch/s390/kernel/head.S (revision 4bedea94545165364618d403d03b61d797acba0b)
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   __LC_IO_NEW_PSW(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        l     %r12,.Lparm                      # pointer to parameter area
268        st    %r1,IPL_DEVICE-PARMAREA(%r12)    # store ipl device number
269
270#
271# load parameter file from ipl device
272#
273.Lagain1:
274 	l     %r2,INITRD_START-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-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-PARMAREA(%r12)  # load adr. of ramdisk
326        bas   %r14,.Lloader                    # load ramdisk
327 	st    %r2,INITRD_SIZE-PARMAREA(%r12)   # store size of ramdisk
328        ltr   %r2,%r2
329        bnz   .Lrdcont
330        st    %r2,INITRD_START-PARMAREA(%r12)  # no ramdisk found, null it
331.Lrdcont:
332	l     %r2,INITRD_START-PARMAREA(%r12)
333
334	clc   0(3,%r2),.L_hdr		       # skip HDRx and EOFx
335	bz    .Lagain2
336	clc   0(3,%r2),.L_eof
337	bz    .Lagain2
338
339#ifdef CONFIG_IPL_VM
340#
341# reset files in VM reader
342#
343        stidp __LC_CPUID                       # store cpuid
344	tm    __LC_CPUID,0xff                  # running VM ?
345	bno   .Lnoreset
346        la    %r2,.Lreset
347        lhi   %r3,26
348	diag  %r2,%r3,8
349	mvc   0x78(8),.Lrdrnewpsw              # set up IO interrupt psw
350.Lwaitrdrirq:
351	lpsw  .Lrdrwaitpsw
352.Lrdrint:
353	c     %r1,0xb8                         # compare subchannel number
354	bne   .Lwaitrdrirq
355	la    %r5,.Lirb
356	tsch  0(%r5)
357.Lnoreset:
358        b     .Lnoload
359
360	.align 8
361.Lrdrnewpsw:
362	.long  0x00080000,0x80000000+.Lrdrint
363.Lrdrwaitpsw:
364	.long  0x020a0000,0x80000000+.Lrdrint
365#endif
366
367#
368# everything loaded, go for it
369#
370.Lnoload:
371        l     %r1,.Lstartup
372        br    %r1
373
374.Lparm:	.long  PARMAREA
375.Lstartup: .long startup
376.Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
377.Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
378        .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
379        .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
380.L_eof: .long  0xc5d6c600       /* C'EOF' */
381.L_hdr: .long  0xc8c4d900       /* C'HDR' */
382
383#endif  /* CONFIG_IPL */
384
385#
386# SALIPL loader support. Based on a patch by Rob van der Heij.
387# This entry point is called directly from the SALIPL loader and
388# doesn't need a builtin ipl record.
389#
390        .org  0x800
391	.globl start
392start:
393	stm   %r0,%r15,0x07b0		# store registers
394	basr  %r12,%r0
395.base:
396	l     %r11,.parm
397	l     %r8,.cmd			# pointer to command buffer
398
399	ltr   %r9,%r9			# do we have SALIPL parameters?
400	bp    .sk8x8
401
402	mvc   0(64,%r8),0x00b0		# copy saved registers
403	xc    64(240-64,%r8),0(%r8)	# remainder of buffer
404	tr    0(64,%r8),.lowcase
405	b     .gotr
406.sk8x8:
407	mvc   0(240,%r8),0(%r9)		# copy iplparms into buffer
408.gotr:
409	l     %r10,.tbl			# EBCDIC to ASCII table
410	tr    0(240,%r8),0(%r10)
411	stidp __LC_CPUID		# Are we running on VM maybe
412	cli   __LC_CPUID,0xff
413	bnz   .test
414	.long 0x83300060		# diag 3,0,x'0060' - storage size
415	b     .done
416.test:
417	mvc   0x68(8),.pgmnw		# set up pgm check handler
418	l     %r2,.fourmeg
419	lr    %r3,%r2
420	bctr  %r3,%r0			# 4M-1
421.loop:  iske  %r0,%r3
422	ar    %r3,%r2
423.pgmx:
424	sr    %r3,%r2
425	la    %r3,1(%r3)
426.done:
427        l     %r1,.memsize
428	st    %r3,0(%r1)
429	slr   %r0,%r0
430	st    %r0,INITRD_SIZE-PARMAREA(%r11)
431	st    %r0,INITRD_START-PARMAREA(%r11)
432	j     startup                   # continue with startup
433.tbl:	.long _ebcasc			# translate table
434.cmd:	.long COMMAND_LINE		# address of command line buffer
435.parm:	.long PARMAREA
436.memsize: .long memory_size
437.fourmeg: .long 0x00400000      	# 4M
438.pgmnw:	.long 0x00080000,.pgmx
439.lowcase:
440	.byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07
441	.byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
442	.byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17
443	.byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
444	.byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27
445	.byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
446	.byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37
447	.byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
448	.byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47
449	.byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
450	.byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57
451	.byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
452	.byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67
453	.byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
454	.byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77
455	.byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f
456
457	.byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87
458	.byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
459	.byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97
460	.byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
461	.byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7
462	.byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
463	.byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7
464	.byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
465	.byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87	# .abcdefg
466	.byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf	# hi
467	.byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97 	# .jklmnop
468	.byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf	# qr
469	.byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7	# ..stuvwx
470	.byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef	# yz
471	.byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7
472	.byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
473
474#
475# startup-code at 0x10000, running in real mode
476# this is called either by the ipl loader or directly by PSW restart
477# or linload or SALIPL
478#
479        .org  0x10000
480startup:basr  %r13,0                     # get base
481.LPG1:  lctl  %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
482	la    %r12,_pstart-.LPG1(%r13)   # pointer to parameter area
483					 # move IPL device to lowcore
484        mvc   __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
485
486#
487# clear bss memory
488#
489        l     %r2,.Lbss_bgn-.LPG1(%r13) # start of bss
490        l     %r3,.Lbss_end-.LPG1(%r13) # end of bss
491        sr    %r3,%r2                   # length of bss
492        sr    %r4,%r4                   #
493        sr    %r5,%r5                   # set src,length and pad to zero
494        sr    %r0,%r0                   #
495        mvcle %r2,%r4,0                 # clear mem
496        jo    .-4                       # branch back, if not finish
497
498	l     %r2,.Lrcp-.LPG1(%r13)	# Read SCP forced command word
499.Lservicecall:
500	stosm .Lpmask-.LPG1(%r13),0x01	# authorize ext interrupts
501
502	stctl %r0, %r0,.Lcr-.LPG1(%r13)	# get cr0
503	la    %r1,0x200			# set bit 22
504	o     %r1,.Lcr-.LPG1(%r13)	# or old cr0 with r1
505	st    %r1,.Lcr-.LPG1(%r13)
506	lctl  %r0, %r0,.Lcr-.LPG1(%r13)	# load modified cr0
507
508	mvc   __LC_EXT_NEW_PSW(8),.Lpcext-.LPG1(%r13) # set postcall psw
509	la    %r1, .Lsclph-.LPG1(%r13)
510	a     %r1,__LC_EXT_NEW_PSW+4	# set handler
511	st    %r1,__LC_EXT_NEW_PSW+4
512
513	la    %r4,_pstart-.LPG1(%r13)	# %r4 is our index for sccb stuff
514	la    %r1, .Lsccb-PARMAREA(%r4)	# our sccb
515	.insn rre,0xb2200000,%r2,%r1	# service call
516	ipm   %r1
517	srl   %r1,28			# get cc code
518	xr    %r3, %r3
519	chi   %r1,3
520	be    .Lfchunk-.LPG1(%r13)	# leave
521	chi   %r1,2
522	be    .Lservicecall-.LPG1(%r13)
523	lpsw  .Lwaitsclp-.LPG1(%r13)
524.Lsclph:
525	lh    %r1,.Lsccbr-PARMAREA(%r4)
526	chi   %r1,0x10			# 0x0010 is the sucess code
527	je    .Lprocsccb		# let's process the sccb
528	chi   %r1,0x1f0
529	bne   .Lfchunk-.LPG1(%r13)	# unhandled error code
530	c     %r2, .Lrcp-.LPG1(%r13)	# Did we try Read SCP forced
531	bne   .Lfchunk-.LPG1(%r13)	# if no, give up
532	l     %r2, .Lrcp2-.LPG1(%r13)	# try with Read SCP
533	b     .Lservicecall-.LPG1(%r13)
534.Lprocsccb:
535	lhi   %r1,0
536	icm   %r1,3,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
537	jnz   .Lscnd
538	l     %r1,.Lscpincr2-PARMAREA+4(%r4) # otherwise use this one
539.Lscnd:
540	xr    %r3,%r3			# same logic
541	ic    %r3,.Lscpa1-PARMAREA(%r4)
542	chi   %r3,0x00
543	jne   .Lcompmem
544	l     %r3,.Lscpa2-PARMAREA(%r13)
545.Lcompmem:
546	mr    %r2,%r1			# mem in MB on 128-bit
547	l     %r1,.Lonemb-.LPG1(%r13)
548	mr    %r2,%r1			# mem size in bytes in %r3
549	b     .Lfchunk-.LPG1(%r13)
550
551.Lpmask:
552	.byte 0
553.align 8
554.Lpcext:.long  0x00080000,0x80000000
555.Lcr:
556	.long 0x00			# place holder for cr0
557.Lwaitsclp:
558	.long 0x020A0000
559	.long .Lsclph
560.Lrcp:
561	.int 0x00120001			# Read SCP forced code
562.Lrcp2:
563	.int 0x00020001			# Read SCP code
564.Lonemb:
565	.int 0x100000
566.Lfchunk:
567
568#
569# find memory chunks.
570#
571	lr    %r9,%r3			 # end of mem
572	mvc   __LC_PGM_NEW_PSW(8),.Lpcmem-.LPG1(%r13)
573	la    %r1,1                      # test in increments of 128KB
574	sll   %r1,17
575	l     %r3,.Lmchunk-.LPG1(%r13)   # get pointer to memory_chunk array
576	slr   %r4,%r4                    # set start of chunk to zero
577	slr   %r5,%r5                    # set end of chunk to zero
578	slr   %r6,%r6			 # set access code to zero
579	la    %r10, MEMORY_CHUNKS	 # number of chunks
580.Lloop:
581	tprot 0(%r5),0			 # test protection of first byte
582	ipm   %r7
583	srl   %r7,28
584	clr   %r6,%r7			 # compare cc with last access code
585	be    .Lsame-.LPG1(%r13)
586	b     .Lchkmem-.LPG1(%r13)
587.Lsame:
588	ar    %r5,%r1			 # add 128KB to end of chunk
589	bno   .Lloop-.LPG1(%r13)	 # r1 < 0x80000000 -> loop
590.Lchkmem:				 # > 2GB or tprot got a program check
591	clr   %r4,%r5			 # chunk size > 0?
592	be    .Lchkloop-.LPG1(%r13)
593	st    %r4,0(%r3)		 # store start address of chunk
594	lr    %r0,%r5
595	slr   %r0,%r4
596	st    %r0,4(%r3)		 # store size of chunk
597	st    %r6,8(%r3)		 # store type of chunk
598	la    %r3,12(%r3)
599	l     %r4,.Lmemsize-.LPG1(%r13)	 # address of variable memory_size
600	st    %r5,0(%r4)		 # store last end to memory size
601	ahi   %r10,-1			 # update chunk number
602.Lchkloop:
603	lr    %r6,%r7			 # set access code to last cc
604	# we got an exception or we're starting a new
605	# chunk , we must check if we should
606	# still try to find valid memory (if we detected
607	# the amount of available storage), and if we
608	# have chunks left
609	xr    %r0,%r0
610	clr   %r0,%r9			 # did we detect memory?
611	je    .Ldonemem			 # if not, leave
612	chi   %r10,0			 # do we have chunks left?
613	je    .Ldonemem
614	alr   %r5,%r1			 # add 128KB to end of chunk
615	lr    %r4,%r5			 # potential new chunk
616	clr    %r5,%r9			 # should we go on?
617	jl     .Lloop
618.Ldonemem:
619        l      %r12,.Lmflags-.LPG1(%r13) # get address of machine_flags
620#
621# find out if we are running under VM
622#
623        stidp  __LC_CPUID               # store cpuid
624	tm     __LC_CPUID,0xff          # running under VM ?
625	bno    .Lnovm-.LPG1(%r13)
626        oi     3(%r12),1                # set VM flag
627.Lnovm:
628        lh     %r0,__LC_CPUID+4         # get cpu version
629        chi    %r0,0x7490               # running on a P/390 ?
630        bne    .Lnop390-.LPG1(%r13)
631        oi     3(%r12),4                # set P/390 flag
632.Lnop390:
633
634#
635# find out if we have an IEEE fpu
636#
637        mvc    __LC_PGM_NEW_PSW(8),.Lpcfpu-.LPG1(%r13)
638	efpc   %r0,0                    # test IEEE extract fpc instruction
639        oi     3(%r12),2                # set IEEE fpu flag
640.Lchkfpu:
641
642#
643# find out if we have the CSP instruction
644#
645       mvc    __LC_PGM_NEW_PSW(8),.Lpccsp-.LPG1(%r13)
646       la     %r0,0
647       lr     %r1,%r0
648       la     %r2,4
649       csp    %r0,%r2                   # Test CSP instruction
650       oi     3(%r12),8                 # set CSP flag
651.Lchkcsp:
652
653#
654# find out if we have the MVPG instruction
655#
656       mvc    __LC_PGM_NEW_PSW(8),.Lpcmvpg-.LPG1(%r13)
657       sr     %r0,%r0
658       la     %r1,0
659       la     %r2,0
660       mvpg   %r1,%r2                   # Test CSP instruction
661       oi     3(%r12),16                # set MVPG flag
662.Lchkmvpg:
663
664#
665# find out if we have the IDTE instruction
666#
667	mvc	__LC_PGM_NEW_PSW(8),.Lpcidte-.LPG1(%r13)
668	.long	0xb2b10000		# store facility list
669	tm	0xc8,0x08		# check bit for clearing-by-ASCE
670	bno	.Lchkidte-.LPG1(%r13)
671	lhi	%r1,2094
672	lhi	%r2,0
673	.long	0xb98e2001
674	oi	3(%r12),0x80		# set IDTE flag
675.Lchkidte:
676
677        lpsw  .Lentry-.LPG1(13)         # jump to _stext in primary-space,
678                                        # virtual and never return ...
679        .align 8
680.Lentry:.long  0x00080000,0x80000000 + _stext
681.Lctl:  .long  0x04b50002               # cr0: various things
682        .long  0                        # cr1: primary space segment table
683        .long  .Lduct                   # cr2: dispatchable unit control table
684        .long  0                        # cr3: instruction authorization
685        .long  0                        # cr4: instruction authorization
686        .long  0xffffffff               # cr5: primary-aste origin
687        .long  0                        # cr6:  I/O interrupts
688        .long  0                        # cr7:  secondary space segment table
689        .long  0                        # cr8:  access registers translation
690        .long  0                        # cr9:  tracing off
691        .long  0                        # cr10: tracing off
692        .long  0                        # cr11: tracing off
693        .long  0                        # cr12: tracing off
694        .long  0                        # cr13: home space segment table
695        .long  0xc0000000               # cr14: machine check handling off
696        .long  0                        # cr15: linkage stack operations
697.Lpcmem:.long  0x00080000,0x80000000 + .Lchkmem
698.Lpcfpu:.long  0x00080000,0x80000000 + .Lchkfpu
699.Lpccsp:.long  0x00080000,0x80000000 + .Lchkcsp
700.Lpcmvpg:.long 0x00080000,0x80000000 + .Lchkmvpg
701.Lpcidte:.long 0x00080000,0x80000000 + .Lchkidte
702.Lmemsize:.long memory_size
703.Lmchunk:.long memory_chunk
704.Lmflags:.long machine_flags
705.Lbss_bgn:  .long  __bss_start
706.Lbss_end:  .long  _end
707
708	.org PARMAREA-64
709.Lduct:	.long 0,0,0,0,0,0,0,0
710	.long 0,0,0,0,0,0,0,0
711
712#
713# params at 10400 (setup.h)
714#
715	.org   PARMAREA
716	.global _pstart
717_pstart:
718        .long  0,0                      # IPL_DEVICE
719        .long  0,RAMDISK_ORIGIN         # INITRD_START
720        .long  0,RAMDISK_SIZE           # INITRD_SIZE
721
722        .org   COMMAND_LINE
723    	.byte  "root=/dev/ram0 ro"
724        .byte  0
725	.org   0x11000
726.Lsccb:
727	.hword 0x1000			# length, one page
728	.byte 0x00,0x00,0x00
729	.byte 0x80			# variable response bit set
730.Lsccbr:
731	.hword 0x00			# response code
732.Lscpincr1:
733	.hword 0x00
734.Lscpa1:
735	.byte 0x00
736	.fill 89,1,0
737.Lscpa2:
738	.int 0x00
739.Lscpincr2:
740	.quad 0x00
741	.fill 3984,1,0
742	.org 0x12000
743	.global _pend
744_pend:
745
746#ifdef CONFIG_SHARED_KERNEL
747	.org   0x100000
748#endif
749
750#
751# startup-code, running in virtual mode
752#
753        .globl _stext
754_stext:	basr  %r13,0                    # get base
755.LPG2:
756#
757# Setup stack
758#
759        l     %r15,.Linittu-.LPG2(%r13)
760	mvc   __LC_CURRENT(4),__TI_task(%r15)
761        ahi   %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
762        st    %r15,__LC_KERNEL_STACK    # set end of kernel stack
763        ahi   %r15,-96
764        xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
765
766# check control registers
767        stctl  %c0,%c15,0(%r15)
768	oi     2(%r15),0x20             # enable sigp external interrupts
769	oi     0(%r15),0x10             # switch on low address protection
770        lctl   %c0,%c15,0(%r15)
771
772#
773        lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
774        l      %r14,.Lstart-.LPG2(%r13)
775        basr   %r14,%r14                # call start_kernel
776#
777# We returned from start_kernel ?!? PANIK
778#
779        basr  %r13,0
780	lpsw  .Ldw-.(%r13)           # load disabled wait psw
781#
782            .align 8
783.Ldw:	    .long  0x000a0000,0x00000000
784.Linittu:   .long  init_thread_union
785.Lstart:    .long  start_kernel
786.Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
787
788