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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/frv/kernel/head.S
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/frv/kernel/head.S')
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1 files changed, 639 insertions, 0 deletions
diff --git a/arch/frv/kernel/head.S b/arch/frv/kernel/head.S
new file mode 100644
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1/* head.S: kernel entry point for FR-V kernel
2 *
3 * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/config.h>
13#include <linux/threads.h>
14#include <linux/linkage.h>
15#include <asm/ptrace.h>
16#include <asm/page.h>
17#include <asm/spr-regs.h>
18#include <asm/mb86943a.h>
19#include <asm/cache.h>
20#include "head.inc"
21
22###############################################################################
23#
24# void _boot(unsigned long magic, char *command_line) __attribute__((noreturn))
25#
26# - if magic is 0xdead1eaf, then command_line is assumed to point to the kernel
27# command line string
28#
29###############################################################################
30 .section .text.head,"ax"
31 .balign 4
32
33 .globl _boot, __head_reference
34 .type _boot,@function
35_boot:
36__head_reference:
37 sethi.p %hi(LED_ADDR),gr30
38 setlo %lo(LED_ADDR),gr30
39
40 LEDS 0x0000
41
42 # calculate reference address for PC-relative stuff
43 call 0f
440: movsg lr,gr26
45 addi gr26,#__head_reference-0b,gr26
46
47 # invalidate and disable both of the caches and turn off the memory access checking
48 dcef @(gr0,gr0),1
49 bar
50
51 sethi.p %hi(~(HSR0_ICE|HSR0_DCE|HSR0_CBM|HSR0_EIMMU|HSR0_EDMMU)),gr4
52 setlo %lo(~(HSR0_ICE|HSR0_DCE|HSR0_CBM|HSR0_EIMMU|HSR0_EDMMU)),gr4
53 movsg hsr0,gr5
54 and gr4,gr5,gr5
55 movgs gr5,hsr0
56 movsg hsr0,gr5
57
58 LEDS 0x0001
59
60 icei @(gr0,gr0),1
61 dcei @(gr0,gr0),1
62 bar
63
64 # turn the instruction cache back on
65 sethi.p %hi(HSR0_ICE),gr4
66 setlo %lo(HSR0_ICE),gr4
67 movsg hsr0,gr5
68 or gr4,gr5,gr5
69 movgs gr5,hsr0
70 movsg hsr0,gr5
71
72 bar
73
74 LEDS 0x0002
75
76 # retrieve the parameters (including command line) before we overwrite them
77 sethi.p %hi(0xdead1eaf),gr7
78 setlo %lo(0xdead1eaf),gr7
79 subcc gr7,gr8,gr0,icc0
80 bne icc0,#0,__head_no_parameters
81
82 sethi.p %hi(redboot_command_line-1),gr6
83 setlo %lo(redboot_command_line-1),gr6
84 sethi.p %hi(__head_reference),gr4
85 setlo %lo(__head_reference),gr4
86 sub gr6,gr4,gr6
87 add.p gr6,gr26,gr6
88 subi gr9,#1,gr9
89 setlos.p #511,gr4
90 setlos #1,gr5
91
92__head_copy_cmdline:
93 ldubu.p @(gr9,gr5),gr16
94 subicc gr4,#1,gr4,icc0
95 stbu.p gr16,@(gr6,gr5)
96 subicc gr16,#0,gr0,icc1
97 bls icc0,#0,__head_end_cmdline
98 bne icc1,#1,__head_copy_cmdline
99__head_end_cmdline:
100 stbu gr0,@(gr6,gr5)
101__head_no_parameters:
102
103###############################################################################
104#
105# we need to relocate the SDRAM to 0x00000000 (linux) or 0xC0000000 (uClinux)
106# - note that we're going to have to run entirely out of the icache whilst
107# fiddling with the SDRAM controller registers
108#
109###############################################################################
110#ifdef CONFIG_MMU
111 call __head_fr451_describe_sdram
112
113#else
114 movsg psr,gr5
115 srli gr5,#28,gr5
116 subicc gr5,#3,gr0,icc0
117 beq icc0,#0,__head_fr551_sdram
118
119 call __head_fr401_describe_sdram
120 bra __head_do_sdram
121
122__head_fr551_sdram:
123 call __head_fr555_describe_sdram
124 LEDS 0x000d
125
126__head_do_sdram:
127#endif
128
129 # preload the registers with invalid values in case any DBR/DARS are marked not present
130 sethi.p %hi(0xfe000000),gr17 ; unused SDRAM DBR value
131 setlo %lo(0xfe000000),gr17
132 or.p gr17,gr0,gr20
133 or gr17,gr0,gr21
134 or.p gr17,gr0,gr22
135 or gr17,gr0,gr23
136
137 # consult the SDRAM controller CS address registers
138 cld @(gr14,gr0 ),gr20, cc0,#1 ; DBR0 / DARS0
139 cld @(gr14,gr11),gr21, cc1,#1 ; DBR1 / DARS1
140 cld @(gr14,gr12),gr22, cc2,#1 ; DBR2 / DARS2
141 cld.p @(gr14,gr13),gr23, cc3,#1 ; DBR3 / DARS3
142
143 sll gr20,gr15,gr20 ; shift values up for FR551
144 sll gr21,gr15,gr21
145 sll gr22,gr15,gr22
146 sll gr23,gr15,gr23
147
148 LEDS 0x0003
149
150 # assume the lowest valid CS line to be the SDRAM base and get its address
151 subcc gr20,gr17,gr0,icc0
152 subcc.p gr21,gr17,gr0,icc1
153 subcc gr22,gr17,gr0,icc2
154 subcc.p gr23,gr17,gr0,icc3
155 ckne icc0,cc4 ; T if DBR0 != 0xfe000000
156 ckne icc1,cc5
157 ckne icc2,cc6
158 ckne icc3,cc7
159 cor gr23,gr0,gr24, cc7,#1 ; GR24 = SDRAM base
160 cor gr22,gr0,gr24, cc6,#1
161 cor gr21,gr0,gr24, cc5,#1
162 cor gr20,gr0,gr24, cc4,#1
163
164 # calculate the displacement required to get the SDRAM into the right place in memory
165 sethi.p %hi(__sdram_base),gr16
166 setlo %lo(__sdram_base),gr16
167 sub gr16,gr24,gr16 ; delta = __sdram_base - DBRx
168
169 # calculate the new values to go in the controller regs
170 cadd.p gr20,gr16,gr20, cc4,#1 ; DCS#0 (new) = DCS#0 (old) + delta
171 cadd gr21,gr16,gr21, cc5,#1
172 cadd.p gr22,gr16,gr22, cc6,#1
173 cadd gr23,gr16,gr23, cc7,#1
174
175 srl gr20,gr15,gr20 ; shift values down for FR551
176 srl gr21,gr15,gr21
177 srl gr22,gr15,gr22
178 srl gr23,gr15,gr23
179
180 # work out the address at which the reg updater resides and lock it into icache
181 # also work out the address the updater will jump to when finished
182 sethi.p %hi(__head_move_sdram-__head_reference),gr18
183 setlo %lo(__head_move_sdram-__head_reference),gr18
184 sethi.p %hi(__head_sdram_moved-__head_reference),gr19
185 setlo %lo(__head_sdram_moved-__head_reference),gr19
186 add.p gr18,gr26,gr18
187 add gr19,gr26,gr19
188 add.p gr19,gr16,gr19 ; moved = addr + (__sdram_base - DBRx)
189 add gr18,gr5,gr4 ; two cachelines probably required
190
191 icpl gr18,gr0,#1 ; load and lock the cachelines
192 icpl gr4,gr0,#1
193 LEDS 0x0004
194 membar
195 bar
196 jmpl @(gr18,gr0)
197
198 .balign L1_CACHE_BYTES
199__head_move_sdram:
200 cst gr20,@(gr14,gr0 ), cc4,#1
201 cst gr21,@(gr14,gr11), cc5,#1
202 cst gr22,@(gr14,gr12), cc6,#1
203 cst gr23,@(gr14,gr13), cc7,#1
204 cld @(gr14,gr0 ),gr20, cc4,#1
205 cld @(gr14,gr11),gr21, cc5,#1
206 cld @(gr14,gr12),gr22, cc4,#1
207 cld @(gr14,gr13),gr23, cc7,#1
208 bar
209 membar
210 jmpl @(gr19,gr0)
211
212 .balign L1_CACHE_BYTES
213__head_sdram_moved:
214 icul gr18
215 add gr18,gr5,gr4
216 icul gr4
217 icei @(gr0,gr0),1
218 dcei @(gr0,gr0),1
219
220 LEDS 0x0005
221
222 # recalculate reference address
223 call 0f
2240: movsg lr,gr26
225 addi gr26,#__head_reference-0b,gr26
226
227
228###############################################################################
229#
230# move the kernel image down to the bottom of the SDRAM
231#
232###############################################################################
233 sethi.p %hi(__kernel_image_size_no_bss+15),gr4
234 setlo %lo(__kernel_image_size_no_bss+15),gr4
235 srli.p gr4,#4,gr4 ; count
236 or gr26,gr26,gr16 ; source
237
238 sethi.p %hi(__sdram_base),gr17 ; destination
239 setlo %lo(__sdram_base),gr17
240
241 setlos #8,gr5
242 sub.p gr16,gr5,gr16 ; adjust src for LDDU
243 sub gr17,gr5,gr17 ; adjust dst for LDDU
244
245 sethi.p %hi(__head_move_kernel-__head_reference),gr18
246 setlo %lo(__head_move_kernel-__head_reference),gr18
247 sethi.p %hi(__head_kernel_moved-__head_reference+__sdram_base),gr19
248 setlo %lo(__head_kernel_moved-__head_reference+__sdram_base),gr19
249 add gr18,gr26,gr18
250 icpl gr18,gr0,#1
251 jmpl @(gr18,gr0)
252
253 .balign 32
254__head_move_kernel:
255 lddu @(gr16,gr5),gr10
256 lddu @(gr16,gr5),gr12
257 stdu.p gr10,@(gr17,gr5)
258 subicc gr4,#1,gr4,icc0
259 stdu.p gr12,@(gr17,gr5)
260 bhi icc0,#0,__head_move_kernel
261 jmpl @(gr19,gr0)
262
263 .balign 32
264__head_kernel_moved:
265 icul gr18
266 icei @(gr0,gr0),1
267 dcei @(gr0,gr0),1
268
269 LEDS 0x0006
270
271 # recalculate reference address
272 call 0f
2730: movsg lr,gr26
274 addi gr26,#__head_reference-0b,gr26
275
276
277###############################################################################
278#
279# rearrange the iomem map and set the protection registers
280#
281###############################################################################
282
283#ifdef CONFIG_MMU
284 LEDS 0x3301
285 call __head_fr451_set_busctl
286 LEDS 0x3303
287 call __head_fr451_survey_sdram
288 LEDS 0x3305
289 call __head_fr451_set_protection
290
291#else
292 movsg psr,gr5
293 srli gr5,#PSR_IMPLE_SHIFT,gr5
294 subicc gr5,#PSR_IMPLE_FR551,gr0,icc0
295 beq icc0,#0,__head_fr555_memmap
296 subicc gr5,#PSR_IMPLE_FR451,gr0,icc0
297 beq icc0,#0,__head_fr451_memmap
298
299 LEDS 0x3101
300 call __head_fr401_set_busctl
301 LEDS 0x3103
302 call __head_fr401_survey_sdram
303 LEDS 0x3105
304 call __head_fr401_set_protection
305 bra __head_done_memmap
306
307__head_fr451_memmap:
308 LEDS 0x3301
309 call __head_fr401_set_busctl
310 LEDS 0x3303
311 call __head_fr401_survey_sdram
312 LEDS 0x3305
313 call __head_fr451_set_protection
314 bra __head_done_memmap
315
316__head_fr555_memmap:
317 LEDS 0x3501
318 call __head_fr555_set_busctl
319 LEDS 0x3503
320 call __head_fr555_survey_sdram
321 LEDS 0x3505
322 call __head_fr555_set_protection
323
324__head_done_memmap:
325#endif
326 LEDS 0x0007
327
328###############################################################################
329#
330# turn the data cache and MMU on
331# - for the FR451 this'll mean that the window through which the kernel is
332# viewed will change
333#
334###############################################################################
335
336#ifdef CONFIG_MMU
337#define MMUMODE HSR0_EIMMU|HSR0_EDMMU|HSR0_EXMMU|HSR0_EDAT|HSR0_XEDAT
338#else
339#define MMUMODE HSR0_EIMMU|HSR0_EDMMU
340#endif
341
342 movsg hsr0,gr5
343
344 sethi.p %hi(MMUMODE),gr4
345 setlo %lo(MMUMODE),gr4
346 or gr4,gr5,gr5
347
348#if defined(CONFIG_FRV_DEFL_CACHE_WTHRU)
349 sethi.p %hi(HSR0_DCE|HSR0_CBM_WRITE_THRU),gr4
350 setlo %lo(HSR0_DCE|HSR0_CBM_WRITE_THRU),gr4
351#elif defined(CONFIG_FRV_DEFL_CACHE_WBACK)
352 sethi.p %hi(HSR0_DCE|HSR0_CBM_COPY_BACK),gr4
353 setlo %lo(HSR0_DCE|HSR0_CBM_COPY_BACK),gr4
354#elif defined(CONFIG_FRV_DEFL_CACHE_WBEHIND)
355 sethi.p %hi(HSR0_DCE|HSR0_CBM_COPY_BACK),gr4
356 setlo %lo(HSR0_DCE|HSR0_CBM_COPY_BACK),gr4
357
358 movsg psr,gr6
359 srli gr6,#24,gr6
360 cmpi gr6,#0x50,icc0 // FR451
361 beq icc0,#0,0f
362 cmpi gr6,#0x40,icc0 // FR405
363 bne icc0,#0,1f
3640:
365 # turn off write-allocate
366 sethi.p %hi(HSR0_NWA),gr6
367 setlo %lo(HSR0_NWA),gr6
368 or gr4,gr6,gr4
3691:
370
371#else
372#error No default cache configuration set
373#endif
374
375 or gr4,gr5,gr5
376 movgs gr5,hsr0
377 bar
378
379 LEDS 0x0008
380
381 sethi.p %hi(__head_mmu_enabled),gr19
382 setlo %lo(__head_mmu_enabled),gr19
383 jmpl @(gr19,gr0)
384
385__head_mmu_enabled:
386 icei @(gr0,gr0),#1
387 dcei @(gr0,gr0),#1
388
389 LEDS 0x0009
390
391#ifdef CONFIG_MMU
392 call __head_fr451_finalise_protection
393#endif
394
395 LEDS 0x000a
396
397###############################################################################
398#
399# set up the runtime environment
400#
401###############################################################################
402
403 # clear the BSS area
404 sethi.p %hi(__bss_start),gr4
405 setlo %lo(__bss_start),gr4
406 sethi.p %hi(_end),gr5
407 setlo %lo(_end),gr5
408 or.p gr0,gr0,gr18
409 or gr0,gr0,gr19
410
4110:
412 stdi gr18,@(gr4,#0)
413 stdi gr18,@(gr4,#8)
414 stdi gr18,@(gr4,#16)
415 stdi.p gr18,@(gr4,#24)
416 addi gr4,#24,gr4
417 subcc gr5,gr4,gr0,icc0
418 bhi icc0,#2,0b
419
420 LEDS 0x000b
421
422 # save the SDRAM details
423 sethi.p %hi(__sdram_old_base),gr4
424 setlo %lo(__sdram_old_base),gr4
425 st gr24,@(gr4,gr0)
426
427 sethi.p %hi(__sdram_base),gr5
428 setlo %lo(__sdram_base),gr5
429 sethi.p %hi(memory_start),gr4
430 setlo %lo(memory_start),gr4
431 st gr5,@(gr4,gr0)
432
433 add gr25,gr5,gr25
434 sethi.p %hi(memory_end),gr4
435 setlo %lo(memory_end),gr4
436 st gr25,@(gr4,gr0)
437
438 # point the TBR at the kernel trap table
439 sethi.p %hi(__entry_kerneltrap_table),gr4
440 setlo %lo(__entry_kerneltrap_table),gr4
441 movgs gr4,tbr
442
443 # set up the exception frame for init
444 sethi.p %hi(__kernel_frame0_ptr),gr28
445 setlo %lo(__kernel_frame0_ptr),gr28
446 sethi.p %hi(_gp),gr16
447 setlo %lo(_gp),gr16
448 sethi.p %hi(__entry_usertrap_table),gr4
449 setlo %lo(__entry_usertrap_table),gr4
450
451 lddi @(gr28,#0),gr28 ; load __frame & current
452 ldi.p @(gr29,#4),gr15 ; set current_thread
453
454 or gr0,gr0,fp
455 or gr28,gr0,sp
456
457 sti.p gr4,@(gr28,REG_TBR)
458 setlos #ISR_EDE|ISR_DTT_DIVBYZERO|ISR_EMAM_EXCEPTION,gr5
459 movgs gr5,isr
460
461 # turn on and off various CPU services
462 movsg psr,gr22
463 sethi.p %hi(#PSR_EM|PSR_EF|PSR_CM|PSR_NEM),gr4
464 setlo %lo(#PSR_EM|PSR_EF|PSR_CM|PSR_NEM),gr4
465 or gr22,gr4,gr22
466 movgs gr22,psr
467
468 andi gr22,#~(PSR_PIL|PSR_PS|PSR_S),gr22
469 ori gr22,#PSR_ET,gr22
470 sti gr22,@(gr28,REG_PSR)
471
472
473###############################################################################
474#
475# set up the registers and jump into the kernel
476#
477###############################################################################
478
479 LEDS 0x000c
480
481 # initialise the processor and the peripherals
482 #call SYMBOL_NAME(processor_init)
483 #call SYMBOL_NAME(unit_init)
484 #LEDS 0x0aff
485
486 sethi.p #0xe5e5,gr3
487 setlo #0xe5e5,gr3
488 or.p gr3,gr0,gr4
489 or gr3,gr0,gr5
490 or.p gr3,gr0,gr6
491 or gr3,gr0,gr7
492 or.p gr3,gr0,gr8
493 or gr3,gr0,gr9
494 or.p gr3,gr0,gr10
495 or gr3,gr0,gr11
496 or.p gr3,gr0,gr12
497 or gr3,gr0,gr13
498 or.p gr3,gr0,gr14
499 or gr3,gr0,gr17
500 or.p gr3,gr0,gr18
501 or gr3,gr0,gr19
502 or.p gr3,gr0,gr20
503 or gr3,gr0,gr21
504 or.p gr3,gr0,gr23
505 or gr3,gr0,gr24
506 or.p gr3,gr0,gr25
507 or gr3,gr0,gr26
508 or.p gr3,gr0,gr27
509# or gr3,gr0,gr30
510 or gr3,gr0,gr31
511 movgs gr0,lr
512 movgs gr0,lcr
513 movgs gr0,ccr
514 movgs gr0,cccr
515
516#ifdef CONFIG_MMU
517 movgs gr3,scr2
518 movgs gr3,scr3
519#endif
520
521 LEDS 0x0fff
522
523 # invoke the debugging stub if present
524 # - arch/frv/kernel/debug-stub.c will shift control directly to init/main.c
525 # (it will not return here)
526 break
527 .globl __debug_stub_init_break
528__debug_stub_init_break:
529
530 # however, if you need to use an ICE, and don't care about using any userspace
531 # debugging tools (such as the ptrace syscall), you can just step over the break
532 # above and get to the kernel this way
533 # look at arch/frv/kernel/debug-stub.c: debug_stub_init() to see what you've missed
534 call start_kernel
535
536 .globl __head_end
537__head_end:
538 .size _boot, .-_boot
539
540 # provide a point for GDB to place a break
541 .section .text.start,"ax"
542 .globl _start
543 .balign 4
544_start:
545 call _boot
546
547 .previous
548###############################################################################
549#
550# split a tile off of the region defined by GR8-GR9
551#
552# ENTRY: EXIT:
553# GR4 - IAMPR value representing tile
554# GR5 - DAMPR value representing tile
555# GR6 - IAMLR value representing tile
556# GR7 - DAMLR value representing tile
557# GR8 region base pointer [saved]
558# GR9 region top pointer updated to exclude new tile
559# GR11 xAMLR mask [saved]
560# GR25 SDRAM size [saved]
561# GR30 LED address [saved]
562#
563# - GR8 and GR9 should be rounded up/down to the nearest megabyte before calling
564#
565###############################################################################
566 .globl __head_split_region
567 .type __head_split_region,@function
568__head_split_region:
569 subcc.p gr9,gr8,gr4,icc0
570 setlos #31,gr5
571 scan.p gr4,gr0,gr6
572 beq icc0,#0,__head_region_empty
573 sub.p gr5,gr6,gr6 ; bit number of highest set bit (1MB=>20)
574 setlos #1,gr4
575 sll.p gr4,gr6,gr4 ; size of region (1 << bitno)
576 subi gr6,#17,gr6 ; 1MB => 0x03
577 slli.p gr6,#4,gr6 ; 1MB => 0x30
578 sub gr9,gr4,gr9 ; move uncovered top down
579
580 or gr9,gr6,gr4
581 ori gr4,#xAMPRx_S_USER|xAMPRx_C_CACHED|xAMPRx_V,gr4
582 or.p gr4,gr0,gr5
583
584 and gr4,gr11,gr6
585 and.p gr5,gr11,gr7
586 bralr
587
588__head_region_empty:
589 or.p gr0,gr0,gr4
590 or gr0,gr0,gr5
591 or.p gr0,gr0,gr6
592 or gr0,gr0,gr7
593 bralr
594 .size __head_split_region, .-__head_split_region
595
596###############################################################################
597#
598# write the 32-bit hex number in GR8 to ttyS0
599#
600###############################################################################
601#if 0
602 .globl __head_write_to_ttyS0
603 .type __head_write_to_ttyS0,@function
604__head_write_to_ttyS0:
605 sethi.p %hi(0xfeff9c00),gr31
606 setlo %lo(0xfeff9c00),gr31
607 setlos #8,gr20
608
6090: ldubi @(gr31,#5*8),gr21
610 andi gr21,#0x60,gr21
611 subicc gr21,#0x60,gr21,icc0
612 bne icc0,#0,0b
613
6141: srli gr8,#28,gr21
615 slli gr8,#4,gr8
616
617 addi gr21,#'0',gr21
618 subicc gr21,#'9',gr0,icc0
619 bls icc0,#2,2f
620 addi gr21,#'A'-'0'-10,gr21
6212:
622 stbi gr21,@(gr31,#0*8)
623 subicc gr20,#1,gr20,icc0
624 bhi icc0,#2,1b
625
626 setlos #'\r',gr21
627 stbi gr21,@(gr31,#0*8)
628
629 setlos #'\n',gr21
630 stbi gr21,@(gr31,#0*8)
631
6323: ldubi @(gr31,#5*8),gr21
633 andi gr21,#0x60,gr21
634 subicc gr21,#0x60,gr21,icc0
635 bne icc0,#0,3b
636 bralr
637
638 .size __head_write_to_ttyS0, .-__head_write_to_ttyS0
639#endif
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-10 17:19:24 -0500