Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-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/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         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
392 start:
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
480 startup: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         lhi   %r1,0x800                 # otherwise report 2GB
539 .Lscnd:
540         lhi   %r3,0x800                 # limit reported memory size to 2GB
541         cr    %r1,%r3
542         jl    .Lno2gb
543         lr    %r1,%r3
544 .Lno2gb:
545         xr    %r3,%r3                   # same logic
546         ic    %r3,.Lscpa1-PARMAREA(%r4)
547         chi   %r3,0x00
548         jne   .Lcompmem
549         l     %r3,.Lscpa2-PARMAREA(%r13)
550 .Lcompmem:
551         mr    %r2,%r1                   # mem in MB on 128-bit
552         l     %r1,.Lonemb-.LPG1(%r13)
553         mr    %r2,%r1                   # mem size in bytes in %r3
554         b     .Lfchunk-.LPG1(%r13)
555
556 .Lpmask:
557         .byte 0
558 .align 8
559 .Lpcext:.long  0x00080000,0x80000000
560 .Lcr:
561         .long 0x00                      # place holder for cr0
562 .Lwaitsclp:
563         .long 0x020A0000
564         .long .Lsclph
565 .Lrcp:
566         .int 0x00120001                 # Read SCP forced code
567 .Lrcp2:
568         .int 0x00020001                 # Read SCP code
569 .Lonemb:
570         .int 0x100000
571 .Lfchunk:
572
573 #
574 # find memory chunks.
575 #
576         lr    %r9,%r3                    # end of mem
577         mvc   __LC_PGM_NEW_PSW(8),.Lpcmem-.LPG1(%r13)
578         la    %r1,1                      # test in increments of 128KB
579         sll   %r1,17
580         l     %r3,.Lmchunk-.LPG1(%r13)   # get pointer to memory_chunk array
581         slr   %r4,%r4                    # set start of chunk to zero
582         slr   %r5,%r5                    # set end of chunk to zero
583         slr   %r6,%r6                    # set access code to zero
584         la    %r10, MEMORY_CHUNKS        # number of chunks
585 .Lloop:
586         tprot 0(%r5),0                   # test protection of first byte
587         ipm   %r7
588         srl   %r7,28
589         clr   %r6,%r7                    # compare cc with last access code
590         be    .Lsame-.LPG1(%r13)
591         b     .Lchkmem-.LPG1(%r13)
592 .Lsame:
593         ar    %r5,%r1                    # add 128KB to end of chunk
594         bno   .Lloop-.LPG1(%r13)         # r1 < 0x80000000 -> loop
595 .Lchkmem:                                # > 2GB or tprot got a program check
596         clr   %r4,%r5                    # chunk size > 0?
597         be    .Lchkloop-.LPG1(%r13)
598         st    %r4,0(%r3)                 # store start address of chunk
599         lr    %r0,%r5
600         slr   %r0,%r4
601         st    %r0,4(%r3)                 # store size of chunk
602         st    %r6,8(%r3)                 # store type of chunk
603         la    %r3,12(%r3)
604         l     %r4,.Lmemsize-.LPG1(%r13)  # address of variable memory_size
605         st    %r5,0(%r4)                 # store last end to memory size
606         ahi   %r10,-1                    # update chunk number
607 .Lchkloop:
608         lr    %r6,%r7                    # set access code to last cc
609         # we got an exception or we're starting a new
610         # chunk , we must check if we should
611         # still try to find valid memory (if we detected
612         # the amount of available storage), and if we
613         # have chunks left
614         xr    %r0,%r0
615         clr   %r0,%r9                    # did we detect memory?
616         je    .Ldonemem                  # if not, leave
617         chi   %r10,0                     # do we have chunks left?
618         je    .Ldonemem
619         alr   %r5,%r1                    # add 128KB to end of chunk
620         lr    %r4,%r5                    # potential new chunk
621         clr    %r5,%r9                   # should we go on?
622         jl     .Lloop
623 .Ldonemem:              
624         l      %r12,.Lmflags-.LPG1(%r13) # get address of machine_flags
625 #
626 # find out if we are running under VM
627 #
628         stidp  __LC_CPUID               # store cpuid
629         tm     __LC_CPUID,0xff          # running under VM ?
630         bno    .Lnovm-.LPG1(%r13)
631         oi     3(%r12),1                # set VM flag
632 .Lnovm:
633         lh     %r0,__LC_CPUID+4         # get cpu version
634         chi    %r0,0x7490               # running on a P/390 ?
635         bne    .Lnop390-.LPG1(%r13)
636         oi     3(%r12),4                # set P/390 flag
637 .Lnop390:
638
639 #
640 # find out if we have an IEEE fpu
641 #
642         mvc    __LC_PGM_NEW_PSW(8),.Lpcfpu-.LPG1(%r13)
643         efpc   %r0,0                    # test IEEE extract fpc instruction
644         oi     3(%r12),2                # set IEEE fpu flag
645 .Lchkfpu:
646
647 #
648 # find out if we have the CSP instruction
649 #
650        mvc    __LC_PGM_NEW_PSW(8),.Lpccsp-.LPG1(%r13)
651        la     %r0,0
652        lr     %r1,%r0
653        la     %r2,4
654        csp    %r0,%r2                   # Test CSP instruction
655        oi     3(%r12),8                 # set CSP flag
656 .Lchkcsp:
657
658 #
659 # find out if we have the MVPG instruction
660 #
661        mvc    __LC_PGM_NEW_PSW(8),.Lpcmvpg-.LPG1(%r13)
662        sr     %r0,%r0
663        la     %r1,0
664        la     %r2,0
665        mvpg   %r1,%r2                   # Test CSP instruction
666        oi     3(%r12),16                # set MVPG flag
667 .Lchkmvpg:
668
669 #
670 # find out if we have the IDTE instruction
671 #
672         mvc     __LC_PGM_NEW_PSW(8),.Lpcidte-.LPG1(%r13)
673         .long   0xb2b10000              # store facility list
674         tm      0xc8,0x08               # check bit for clearing-by-ASCE
675         bno     .Lchkidte-.LPG1(%r13)
676         lhi     %r1,2094
677         lhi     %r2,0
678         .long   0xb98e2001
679         oi      3(%r12),0x80            # set IDTE flag
680 .Lchkidte:
681
682         lpsw  .Lentry-.LPG1(13)         # jump to _stext in primary-space,
683                                         # virtual and never return ...
684         .align 8
685 .Lentry:.long  0x00080000,0x80000000 + _stext
686 .Lctl:  .long  0x04b50002               # cr0: various things
687         .long  0                        # cr1: primary space segment table
688         .long  .Lduct                   # cr2: dispatchable unit control table
689         .long  0                        # cr3: instruction authorization
690         .long  0                        # cr4: instruction authorization
691         .long  0xffffffff               # cr5: primary-aste origin
692         .long  0                        # cr6:  I/O interrupts
693         .long  0                        # cr7:  secondary space segment table
694         .long  0                        # cr8:  access registers translation
695         .long  0                        # cr9:  tracing off
696         .long  0                        # cr10: tracing off
697         .long  0                        # cr11: tracing off
698         .long  0                        # cr12: tracing off
699         .long  0                        # cr13: home space segment table
700         .long  0xc0000000               # cr14: machine check handling off
701         .long  0                        # cr15: linkage stack operations
702 .Lpcmem:.long  0x00080000,0x80000000 + .Lchkmem
703 .Lpcfpu:.long  0x00080000,0x80000000 + .Lchkfpu
704 .Lpccsp:.long  0x00080000,0x80000000 + .Lchkcsp
705 .Lpcmvpg:.long 0x00080000,0x80000000 + .Lchkmvpg
706 .Lpcidte:.long 0x00080000,0x80000000 + .Lchkidte
707 .Lmemsize:.long memory_size
708 .Lmchunk:.long memory_chunk
709 .Lmflags:.long machine_flags
710 .Lbss_bgn:  .long  __bss_start
711 .Lbss_end:  .long  _end
712
713         .org PARMAREA-64
714 .Lduct: .long 0,0,0,0,0,0,0,0
715         .long 0,0,0,0,0,0,0,0
716
717 #
718 # params at 10400 (setup.h)
719 #
720         .org   PARMAREA
721         .global _pstart
722 _pstart:        
723         .long  0,0                      # IPL_DEVICE
724         .long  0,RAMDISK_ORIGIN         # INITRD_START
725         .long  0,RAMDISK_SIZE           # INITRD_SIZE
726
727         .org   COMMAND_LINE
728         .byte  "root=/dev/ram0 ro"
729         .byte  0
730         .org   0x11000
731 .Lsccb:
732         .hword 0x1000                   # length, one page
733         .byte 0x00,0x00,0x00
734         .byte 0x80                      # variable response bit set
735 .Lsccbr:
736         .hword 0x00                     # response code
737 .Lscpincr1:
738         .hword 0x00
739 .Lscpa1:
740         .byte 0x00
741         .fill 89,1,0
742 .Lscpa2:
743         .int 0x00
744 .Lscpincr2:
745         .quad 0x00
746         .fill 3984,1,0
747         .org 0x12000
748         .global _pend
749 _pend:  
750
751 #ifdef CONFIG_SHARED_KERNEL
752         .org   0x100000
753 #endif
754
755 #
756 # startup-code, running in virtual mode
757 #
758         .globl _stext
759 _stext: basr  %r13,0                    # get base
760 .LPG2:
761 #
762 # Setup stack
763 #
764         l     %r15,.Linittu-.LPG2(%r13)
765         mvc   __LC_CURRENT(4),__TI_task(%r15)
766         ahi   %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
767         st    %r15,__LC_KERNEL_STACK    # set end of kernel stack
768         ahi   %r15,-96
769         xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
770
771 # check control registers
772         stctl  %c0,%c15,0(%r15)
773         oi     2(%r15),0x40             # enable sigp emergency signal
774         oi     0(%r15),0x10             # switch on low address protection
775         lctl   %c0,%c15,0(%r15)
776
777 #
778         lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
779         l      %r14,.Lstart-.LPG2(%r13)
780         basr   %r14,%r14                # call start_kernel
781 #
782 # We returned from start_kernel ?!? PANIK
783 #
784         basr  %r13,0
785         lpsw  .Ldw-.(%r13)           # load disabled wait psw
786 #
787             .align 8
788 .Ldw:       .long  0x000a0000,0x00000000
789 .Linittu:   .long  init_thread_union
790 .Lstart:    .long  start_kernel
791 .Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
792