Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-for-linus-2.6
[linux-2.6] / arch / s390 / kernel / head.S
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/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
261 iplstart:
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         la    %r5,.Lirb
350         stsch 0(%r5)                           # check if irq is pending
351         tm    30(%r5),0x0f                     # by verifying if any of the
352         bnz   .Lwaitforirq                     # activity or status control
353         tm    31(%r5),0xff                     # bits is set in the schib
354         bz    .Lnoreset
355 .Lwaitforirq:
356         mvc   0x78(8),.Lrdrnewpsw              # set up IO interrupt psw
357 .Lwaitrdrirq:
358         lpsw  .Lrdrwaitpsw
359 .Lrdrint:
360         c     %r1,0xb8                         # compare subchannel number
361         bne   .Lwaitrdrirq
362         la    %r5,.Lirb
363         tsch  0(%r5)
364 .Lnoreset:
365         b     .Lnoload
366
367         .align 8
368 .Lrdrnewpsw:
369         .long  0x00080000,0x80000000+.Lrdrint
370 .Lrdrwaitpsw:
371         .long  0x020a0000,0x80000000+.Lrdrint
372 #endif
373
374 #
375 # everything loaded, go for it
376 #
377 .Lnoload:
378         l     %r1,.Lstartup
379         br    %r1
380
381 .Lparm: .long  PARMAREA
382 .Lstartup: .long startup
383 .Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
384 .Lreset:.byte  0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
385         .byte  0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
386         .byte  0xc8,0xd6,0xd3,0xc4             # "change rdr all keep nohold"
387 .L_eof: .long  0xc5d6c600       /* C'EOF' */
388 .L_hdr: .long  0xc8c4d900       /* C'HDR' */
389
390 #endif  /* CONFIG_IPL */
391
392 #
393 # SALIPL loader support. Based on a patch by Rob van der Heij.
394 # This entry point is called directly from the SALIPL loader and
395 # doesn't need a builtin ipl record.
396 #
397         .org  0x800
398         .globl start
399 start:
400         stm   %r0,%r15,0x07b0           # store registers
401         basr  %r12,%r0
402 .base:
403         l     %r11,.parm
404         l     %r8,.cmd                  # pointer to command buffer
405
406         ltr   %r9,%r9                   # do we have SALIPL parameters?
407         bp    .sk8x8
408
409         mvc   0(64,%r8),0x00b0          # copy saved registers
410         xc    64(240-64,%r8),0(%r8)     # remainder of buffer
411         tr    0(64,%r8),.lowcase        
412         b     .gotr
413 .sk8x8:
414         mvc   0(240,%r8),0(%r9)         # copy iplparms into buffer
415 .gotr:
416         l     %r10,.tbl                 # EBCDIC to ASCII table
417         tr    0(240,%r8),0(%r10)
418         stidp __LC_CPUID                # Are we running on VM maybe
419         cli   __LC_CPUID,0xff
420         bnz   .test
421         .long 0x83300060                # diag 3,0,x'0060' - storage size
422         b     .done
423 .test:
424         mvc   0x68(8),.pgmnw            # set up pgm check handler
425         l     %r2,.fourmeg
426         lr    %r3,%r2
427         bctr  %r3,%r0                   # 4M-1
428 .loop:  iske  %r0,%r3
429         ar    %r3,%r2
430 .pgmx:
431         sr    %r3,%r2
432         la    %r3,1(%r3)
433 .done:
434         l     %r1,.memsize
435         st    %r3,0(%r1)
436         slr   %r0,%r0
437         st    %r0,INITRD_SIZE-PARMAREA(%r11)
438         st    %r0,INITRD_START-PARMAREA(%r11)
439         j     startup                   # continue with startup
440 .tbl:   .long _ebcasc                   # translate table
441 .cmd:   .long COMMAND_LINE              # address of command line buffer
442 .parm:  .long PARMAREA
443 .memsize: .long memory_size
444 .fourmeg: .long 0x00400000              # 4M
445 .pgmnw: .long 0x00080000,.pgmx
446 .lowcase:
447         .byte 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07 
448         .byte 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f
449         .byte 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17 
450         .byte 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
451         .byte 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27 
452         .byte 0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
453         .byte 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37 
454         .byte 0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f
455         .byte 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47 
456         .byte 0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f
457         .byte 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57 
458         .byte 0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f
459         .byte 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67 
460         .byte 0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f
461         .byte 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77 
462         .byte 0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f
463
464         .byte 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87 
465         .byte 0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f
466         .byte 0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97 
467         .byte 0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f
468         .byte 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7 
469         .byte 0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf
470         .byte 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7 
471         .byte 0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf
472         .byte 0xc0,0x81,0x82,0x83,0x84,0x85,0x86,0x87   # .abcdefg 
473         .byte 0x88,0x89,0xca,0xcb,0xcc,0xcd,0xce,0xcf   # hi
474         .byte 0xd0,0x91,0x92,0x93,0x94,0x95,0x96,0x97   # .jklmnop
475         .byte 0x98,0x99,0xda,0xdb,0xdc,0xdd,0xde,0xdf   # qr
476         .byte 0xe0,0xe1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7   # ..stuvwx
477         .byte 0xa8,0xa9,0xea,0xeb,0xec,0xed,0xee,0xef   # yz
478         .byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7 
479         .byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
480
481 #
482 # startup-code at 0x10000, running in real mode
483 # this is called either by the ipl loader or directly by PSW restart
484 # or linload or SALIPL
485 #
486         .org  0x10000
487 startup:basr  %r13,0                     # get base
488 .LPG1:  lctl  %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
489         la    %r12,_pstart-.LPG1(%r13)   # pointer to parameter area
490                                          # move IPL device to lowcore
491         mvc   __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
492         
493 #
494 # clear bss memory
495 #
496         l     %r2,.Lbss_bgn-.LPG1(%r13) # start of bss
497         l     %r3,.Lbss_end-.LPG1(%r13) # end of bss
498         sr    %r3,%r2                   # length of bss
499         sr    %r4,%r4                   #
500         sr    %r5,%r5                   # set src,length and pad to zero
501         sr    %r0,%r0                   #
502         mvcle %r2,%r4,0                 # clear mem
503         jo    .-4                       # branch back, if not finish
504
505         l     %r2,.Lrcp-.LPG1(%r13)     # Read SCP forced command word
506 .Lservicecall:
507         stosm .Lpmask-.LPG1(%r13),0x01  # authorize ext interrupts
508
509         stctl %r0, %r0,.Lcr-.LPG1(%r13) # get cr0
510         la    %r1,0x200                 # set bit 22
511         o     %r1,.Lcr-.LPG1(%r13)      # or old cr0 with r1
512         st    %r1,.Lcr-.LPG1(%r13)
513         lctl  %r0, %r0,.Lcr-.LPG1(%r13) # load modified cr0
514
515         mvc   __LC_EXT_NEW_PSW(8),.Lpcext-.LPG1(%r13) # set postcall psw
516         la    %r1, .Lsclph-.LPG1(%r13)
517         a     %r1,__LC_EXT_NEW_PSW+4    # set handler
518         st    %r1,__LC_EXT_NEW_PSW+4
519
520         la    %r4,_pstart-.LPG1(%r13)   # %r4 is our index for sccb stuff
521         la    %r1, .Lsccb-PARMAREA(%r4) # our sccb
522         .insn rre,0xb2200000,%r2,%r1    # service call
523         ipm   %r1
524         srl   %r1,28                    # get cc code
525         xr    %r3, %r3
526         chi   %r1,3
527         be    .Lfchunk-.LPG1(%r13)      # leave
528         chi   %r1,2
529         be    .Lservicecall-.LPG1(%r13)
530         lpsw  .Lwaitsclp-.LPG1(%r13)
531 .Lsclph:
532         lh    %r1,.Lsccbr-PARMAREA(%r4)
533         chi   %r1,0x10                  # 0x0010 is the sucess code
534         je    .Lprocsccb                # let's process the sccb
535         chi   %r1,0x1f0
536         bne   .Lfchunk-.LPG1(%r13)      # unhandled error code
537         c     %r2, .Lrcp-.LPG1(%r13)    # Did we try Read SCP forced
538         bne   .Lfchunk-.LPG1(%r13)      # if no, give up
539         l     %r2, .Lrcp2-.LPG1(%r13)   # try with Read SCP
540         b     .Lservicecall-.LPG1(%r13)
541 .Lprocsccb:
542         lhi   %r1,0
543         icm   %r1,3,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
544         jnz   .Lscnd
545         lhi   %r1,0x800                 # otherwise report 2GB
546 .Lscnd:
547         lhi   %r3,0x800                 # limit reported memory size to 2GB
548         cr    %r1,%r3
549         jl    .Lno2gb
550         lr    %r1,%r3
551 .Lno2gb:
552         xr    %r3,%r3                   # same logic
553         ic    %r3,.Lscpa1-PARMAREA(%r4)
554         chi   %r3,0x00
555         jne   .Lcompmem
556         l     %r3,.Lscpa2-PARMAREA(%r13)
557 .Lcompmem:
558         mr    %r2,%r1                   # mem in MB on 128-bit
559         l     %r1,.Lonemb-.LPG1(%r13)
560         mr    %r2,%r1                   # mem size in bytes in %r3
561         b     .Lfchunk-.LPG1(%r13)
562
563 .Lpmask:
564         .byte 0
565 .align 8
566 .Lpcext:.long  0x00080000,0x80000000
567 .Lcr:
568         .long 0x00                      # place holder for cr0
569 .Lwaitsclp:
570         .long 0x020A0000
571         .long .Lsclph
572 .Lrcp:
573         .int 0x00120001                 # Read SCP forced code
574 .Lrcp2:
575         .int 0x00020001                 # Read SCP code
576 .Lonemb:
577         .int 0x100000
578 .Lfchunk:
579
580 #
581 # find memory chunks.
582 #
583         lr    %r9,%r3                    # end of mem
584         mvc   __LC_PGM_NEW_PSW(8),.Lpcmem-.LPG1(%r13)
585         la    %r1,1                      # test in increments of 128KB
586         sll   %r1,17
587         l     %r3,.Lmchunk-.LPG1(%r13)   # get pointer to memory_chunk array
588         slr   %r4,%r4                    # set start of chunk to zero
589         slr   %r5,%r5                    # set end of chunk to zero
590         slr   %r6,%r6                    # set access code to zero
591         la    %r10, MEMORY_CHUNKS        # number of chunks
592 .Lloop:
593         tprot 0(%r5),0                   # test protection of first byte
594         ipm   %r7
595         srl   %r7,28
596         clr   %r6,%r7                    # compare cc with last access code
597         be    .Lsame-.LPG1(%r13)
598         b     .Lchkmem-.LPG1(%r13)
599 .Lsame:
600         ar    %r5,%r1                    # add 128KB to end of chunk
601         bno   .Lloop-.LPG1(%r13)         # r1 < 0x80000000 -> loop
602 .Lchkmem:                                # > 2GB or tprot got a program check
603         clr   %r4,%r5                    # chunk size > 0?
604         be    .Lchkloop-.LPG1(%r13)
605         st    %r4,0(%r3)                 # store start address of chunk
606         lr    %r0,%r5
607         slr   %r0,%r4
608         st    %r0,4(%r3)                 # store size of chunk
609         st    %r6,8(%r3)                 # store type of chunk
610         la    %r3,12(%r3)
611         l     %r4,.Lmemsize-.LPG1(%r13)  # address of variable memory_size
612         st    %r5,0(%r4)                 # store last end to memory size
613         ahi   %r10,-1                    # update chunk number
614 .Lchkloop:
615         lr    %r6,%r7                    # set access code to last cc
616         # we got an exception or we're starting a new
617         # chunk , we must check if we should
618         # still try to find valid memory (if we detected
619         # the amount of available storage), and if we
620         # have chunks left
621         xr    %r0,%r0
622         clr   %r0,%r9                    # did we detect memory?
623         je    .Ldonemem                  # if not, leave
624         chi   %r10,0                     # do we have chunks left?
625         je    .Ldonemem
626         alr   %r5,%r1                    # add 128KB to end of chunk
627         lr    %r4,%r5                    # potential new chunk
628         clr    %r5,%r9                   # should we go on?
629         jl     .Lloop
630 .Ldonemem:              
631         l      %r12,.Lmflags-.LPG1(%r13) # get address of machine_flags
632 #
633 # find out if we are running under VM
634 #
635         stidp  __LC_CPUID               # store cpuid
636         tm     __LC_CPUID,0xff          # running under VM ?
637         bno    .Lnovm-.LPG1(%r13)
638         oi     3(%r12),1                # set VM flag
639 .Lnovm:
640         lh     %r0,__LC_CPUID+4         # get cpu version
641         chi    %r0,0x7490               # running on a P/390 ?
642         bne    .Lnop390-.LPG1(%r13)
643         oi     3(%r12),4                # set P/390 flag
644 .Lnop390:
645
646 #
647 # find out if we have an IEEE fpu
648 #
649         mvc    __LC_PGM_NEW_PSW(8),.Lpcfpu-.LPG1(%r13)
650         efpc   %r0,0                    # test IEEE extract fpc instruction
651         oi     3(%r12),2                # set IEEE fpu flag
652 .Lchkfpu:
653
654 #
655 # find out if we have the CSP instruction
656 #
657        mvc    __LC_PGM_NEW_PSW(8),.Lpccsp-.LPG1(%r13)
658        la     %r0,0
659        lr     %r1,%r0
660        la     %r2,4
661        csp    %r0,%r2                   # Test CSP instruction
662        oi     3(%r12),8                 # set CSP flag
663 .Lchkcsp:
664
665 #
666 # find out if we have the MVPG instruction
667 #
668        mvc    __LC_PGM_NEW_PSW(8),.Lpcmvpg-.LPG1(%r13)
669        sr     %r0,%r0
670        la     %r1,0
671        la     %r2,0
672        mvpg   %r1,%r2                   # Test CSP instruction
673        oi     3(%r12),16                # set MVPG flag
674 .Lchkmvpg:
675
676 #
677 # find out if we have the IDTE instruction
678 #
679         mvc     __LC_PGM_NEW_PSW(8),.Lpcidte-.LPG1(%r13)
680         .long   0xb2b10000              # store facility list
681         tm      0xc8,0x08               # check bit for clearing-by-ASCE
682         bno     .Lchkidte-.LPG1(%r13)
683         lhi     %r1,2094
684         lhi     %r2,0
685         .long   0xb98e2001
686         oi      3(%r12),0x80            # set IDTE flag
687 .Lchkidte:
688
689         lpsw  .Lentry-.LPG1(13)         # jump to _stext in primary-space,
690                                         # virtual and never return ...
691         .align 8
692 .Lentry:.long  0x00080000,0x80000000 + _stext
693 .Lctl:  .long  0x04b50002               # cr0: various things
694         .long  0                        # cr1: primary space segment table
695         .long  .Lduct                   # cr2: dispatchable unit control table
696         .long  0                        # cr3: instruction authorization
697         .long  0                        # cr4: instruction authorization
698         .long  0xffffffff               # cr5: primary-aste origin
699         .long  0                        # cr6:  I/O interrupts
700         .long  0                        # cr7:  secondary space segment table
701         .long  0                        # cr8:  access registers translation
702         .long  0                        # cr9:  tracing off
703         .long  0                        # cr10: tracing off
704         .long  0                        # cr11: tracing off
705         .long  0                        # cr12: tracing off
706         .long  0                        # cr13: home space segment table
707         .long  0xc0000000               # cr14: machine check handling off
708         .long  0                        # cr15: linkage stack operations
709 .Lpcmem:.long  0x00080000,0x80000000 + .Lchkmem
710 .Lpcfpu:.long  0x00080000,0x80000000 + .Lchkfpu
711 .Lpccsp:.long  0x00080000,0x80000000 + .Lchkcsp
712 .Lpcmvpg:.long 0x00080000,0x80000000 + .Lchkmvpg
713 .Lpcidte:.long 0x00080000,0x80000000 + .Lchkidte
714 .Lmemsize:.long memory_size
715 .Lmchunk:.long memory_chunk
716 .Lmflags:.long machine_flags
717 .Lbss_bgn:  .long  __bss_start
718 .Lbss_end:  .long  _end
719
720         .org PARMAREA-64
721 .Lduct: .long 0,0,0,0,0,0,0,0
722         .long 0,0,0,0,0,0,0,0
723
724 #
725 # params at 10400 (setup.h)
726 #
727         .org   PARMAREA
728         .global _pstart
729 _pstart:        
730         .long  0,0                      # IPL_DEVICE
731         .long  0,RAMDISK_ORIGIN         # INITRD_START
732         .long  0,RAMDISK_SIZE           # INITRD_SIZE
733
734         .org   COMMAND_LINE
735         .byte  "root=/dev/ram0 ro"
736         .byte  0
737         .org   0x11000
738 .Lsccb:
739         .hword 0x1000                   # length, one page
740         .byte 0x00,0x00,0x00
741         .byte 0x80                      # variable response bit set
742 .Lsccbr:
743         .hword 0x00                     # response code
744 .Lscpincr1:
745         .hword 0x00
746 .Lscpa1:
747         .byte 0x00
748         .fill 89,1,0
749 .Lscpa2:
750         .int 0x00
751 .Lscpincr2:
752         .quad 0x00
753         .fill 3984,1,0
754         .org 0x12000
755         .global _pend
756 _pend:  
757
758 #ifdef CONFIG_SHARED_KERNEL
759         .org   0x100000
760 #endif
761
762 #
763 # startup-code, running in virtual mode
764 #
765         .globl _stext
766 _stext: basr  %r13,0                    # get base
767 .LPG2:
768 #
769 # Setup stack
770 #
771         l     %r15,.Linittu-.LPG2(%r13)
772         mvc   __LC_CURRENT(4),__TI_task(%r15)
773         ahi   %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
774         st    %r15,__LC_KERNEL_STACK    # set end of kernel stack
775         ahi   %r15,-96
776         xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
777
778 # check control registers
779         stctl  %c0,%c15,0(%r15)
780         oi     2(%r15),0x40             # enable sigp emergency signal
781         oi     0(%r15),0x10             # switch on low address protection
782         lctl   %c0,%c15,0(%r15)
783
784 #
785         lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
786         l      %r14,.Lstart-.LPG2(%r13)
787         basr   %r14,%r14                # call start_kernel
788 #
789 # We returned from start_kernel ?!? PANIK
790 #
791         basr  %r13,0
792         lpsw  .Ldw-.(%r13)           # load disabled wait psw
793 #
794             .align 8
795 .Ldw:       .long  0x000a0000,0x00000000
796 .Linittu:   .long  init_thread_union
797 .Lstart:    .long  start_kernel
798 .Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
799