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gerrit.nordix.org / codeaurora / cp-linux / 8d8f6542b666daf5e87de156590e635c2c4da0c0 / . / arch / frv / kernel / head.S
blob: a7d0bea9c03619840686186e9468a693c00f12bb [file] [log] [blame]
Kyle Swenson8d8f6542021-03-15 11:02:55 -0600[diff] [blame^]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/init.h>
13#include <linux/threads.h>
14#include <linux/linkage.h>
15#include <asm/thread_info.h>
16#include <asm/ptrace.h>
17#include <asm/page.h>
18#include <asm/spr-regs.h>
19#include <asm/mb86943a.h>
20#include <asm/cache.h>
21#include "head.inc"
22
23###############################################################################
24#
25# void _boot(unsigned long magic, char *command_line) __attribute__((noreturn))
26#
27# - if magic is 0xdead1eaf, then command_line is assumed to point to the kernel
28# command line string
29#
30###############################################################################
31 __HEAD
32 .balign 4
33
34 .globl _boot, __head_reference
35 .type _boot,@function
36_boot:
37__head_reference:
38 sethi.p %hi(LED_ADDR),gr30
39 setlo %lo(LED_ADDR),gr30
40
41 LEDS 0x0000
42
43 # calculate reference address for PC-relative stuff
44 call 0f
450: movsg lr,gr26
46 addi gr26,#__head_reference-0b,gr26
47
48 # invalidate and disable both of the caches and turn off the memory access checking
49 dcef @(gr0,gr0),1
50 bar
51
52 sethi.p %hi(~(HSR0_ICE|HSR0_DCE|HSR0_CBM|HSR0_EIMMU|HSR0_EDMMU)),gr4
53 setlo %lo(~(HSR0_ICE|HSR0_DCE|HSR0_CBM|HSR0_EIMMU|HSR0_EDMMU)),gr4
54 movsg hsr0,gr5
55 and gr4,gr5,gr5
56 movgs gr5,hsr0
57 movsg hsr0,gr5
58
59 LEDS 0x0001
60
61 icei @(gr0,gr0),1
62 dcei @(gr0,gr0),1
63 bar
64
65 # turn the instruction cache back on
66 sethi.p %hi(HSR0_ICE),gr4
67 setlo %lo(HSR0_ICE),gr4
68 movsg hsr0,gr5
69 or gr4,gr5,gr5
70 movgs gr5,hsr0
71 movsg hsr0,gr5
72
73 bar
74
75 LEDS 0x0002
76
77 # retrieve the parameters (including command line) before we overwrite them
78 sethi.p %hi(0xdead1eaf),gr7
79 setlo %lo(0xdead1eaf),gr7
80 subcc gr7,gr8,gr0,icc0
81 bne icc0,#0,__head_no_parameters
82
83 sethi.p %hi(redboot_command_line-1),gr6
84 setlo %lo(redboot_command_line-1),gr6
85 sethi.p %hi(__head_reference),gr4
86 setlo %lo(__head_reference),gr4
87 sub gr6,gr4,gr6
88 add.p gr6,gr26,gr6
89 subi gr9,#1,gr9
90 setlos.p #511,gr4
91 setlos #1,gr5
92
93__head_copy_cmdline:
94 ldubu.p @(gr9,gr5),gr16
95 subicc gr4,#1,gr4,icc0
96 stbu.p gr16,@(gr6,gr5)
97 subicc gr16,#0,gr0,icc1
98 bls icc0,#0,__head_end_cmdline
99 bne icc1,#1,__head_copy_cmdline
100__head_end_cmdline:
101 stbu gr0,@(gr6,gr5)
102__head_no_parameters:
103
104###############################################################################
105#
106# we need to relocate the SDRAM to 0x00000000 (linux) or 0xC0000000 (uClinux)
107# - note that we're going to have to run entirely out of the icache whilst
108# fiddling with the SDRAM controller registers
109#
110###############################################################################
111#ifdef CONFIG_MMU
112 call __head_fr451_describe_sdram
113
114#else
115 movsg psr,gr5
116 srli gr5,#28,gr5
117 subicc gr5,#3,gr0,icc0
118 beq icc0,#0,__head_fr551_sdram
119
120 call __head_fr401_describe_sdram
121 bra __head_do_sdram
122
123__head_fr551_sdram:
124 call __head_fr555_describe_sdram
125 LEDS 0x000d
126
127__head_do_sdram:
128#endif
129
130 # preload the registers with invalid values in case any DBR/DARS are marked not present
131 sethi.p %hi(0xfe000000),gr17 ; unused SDRAM DBR value
132 setlo %lo(0xfe000000),gr17
133 or.p gr17,gr0,gr20
134 or gr17,gr0,gr21
135 or.p gr17,gr0,gr22
136 or gr17,gr0,gr23
137
138 # consult the SDRAM controller CS address registers
139 cld @(gr14,gr0 ),gr20, cc0,#1 ; DBR0 / DARS0
140 cld @(gr14,gr11),gr21, cc1,#1 ; DBR1 / DARS1
141 cld @(gr14,gr12),gr22, cc2,#1 ; DBR2 / DARS2
142 cld.p @(gr14,gr13),gr23, cc3,#1 ; DBR3 / DARS3
143
144 sll gr20,gr15,gr20 ; shift values up for FR551
145 sll gr21,gr15,gr21
146 sll gr22,gr15,gr22
147 sll gr23,gr15,gr23
148
149 LEDS 0x0003
150
151 # assume the lowest valid CS line to be the SDRAM base and get its address
152 subcc gr20,gr17,gr0,icc0
153 subcc.p gr21,gr17,gr0,icc1
154 subcc gr22,gr17,gr0,icc2
155 subcc.p gr23,gr17,gr0,icc3
156 ckne icc0,cc4 ; T if DBR0 != 0xfe000000
157 ckne icc1,cc5
158 ckne icc2,cc6
159 ckne icc3,cc7
160 cor gr23,gr0,gr24, cc7,#1 ; GR24 = SDRAM base
161 cor gr22,gr0,gr24, cc6,#1
162 cor gr21,gr0,gr24, cc5,#1
163 cor gr20,gr0,gr24, cc4,#1
164
165 # calculate the displacement required to get the SDRAM into the right place in memory
166 sethi.p %hi(__sdram_base),gr16
167 setlo %lo(__sdram_base),gr16
168 sub gr16,gr24,gr16 ; delta = __sdram_base - DBRx
169
170 # calculate the new values to go in the controller regs
171 cadd.p gr20,gr16,gr20, cc4,#1 ; DCS#0 (new) = DCS#0 (old) + delta
172 cadd gr21,gr16,gr21, cc5,#1
173 cadd.p gr22,gr16,gr22, cc6,#1
174 cadd gr23,gr16,gr23, cc7,#1
175
176 srl gr20,gr15,gr20 ; shift values down for FR551
177 srl gr21,gr15,gr21
178 srl gr22,gr15,gr22
179 srl gr23,gr15,gr23
180
181 # work out the address at which the reg updater resides and lock it into icache
182 # also work out the address the updater will jump to when finished
183 sethi.p %hi(__head_move_sdram-__head_reference),gr18
184 setlo %lo(__head_move_sdram-__head_reference),gr18
185 sethi.p %hi(__head_sdram_moved-__head_reference),gr19
186 setlo %lo(__head_sdram_moved-__head_reference),gr19
187 add.p gr18,gr26,gr18
188 add gr19,gr26,gr19
189 add.p gr19,gr16,gr19 ; moved = addr + (__sdram_base - DBRx)
190 add gr18,gr5,gr4 ; two cachelines probably required
191
192 icpl gr18,gr0,#1 ; load and lock the cachelines
193 icpl gr4,gr0,#1
194 LEDS 0x0004
195 membar
196 bar
197 jmpl @(gr18,gr0)
198
199 .balign L1_CACHE_BYTES
200__head_move_sdram:
201 cst gr20,@(gr14,gr0 ), cc4,#1
202 cst gr21,@(gr14,gr11), cc5,#1
203 cst gr22,@(gr14,gr12), cc6,#1
204 cst gr23,@(gr14,gr13), cc7,#1
205 cld @(gr14,gr0 ),gr20, cc4,#1
206 cld @(gr14,gr11),gr21, cc5,#1
207 cld @(gr14,gr12),gr22, cc4,#1
208 cld @(gr14,gr13),gr23, cc7,#1
209 bar
210 membar
211 jmpl @(gr19,gr0)
212
213 .balign L1_CACHE_BYTES
214__head_sdram_moved:
215 icul gr18
216 add gr18,gr5,gr4
217 icul gr4
218 icei @(gr0,gr0),1
219 dcei @(gr0,gr0),1
220
221 LEDS 0x0005
222
223 # recalculate reference address
224 call 0f
2250: movsg lr,gr26
226 addi gr26,#__head_reference-0b,gr26
227
228
229###############################################################################
230#
231# move the kernel image down to the bottom of the SDRAM
232#
233###############################################################################
234 sethi.p %hi(__kernel_image_size_no_bss+15),gr4
235 setlo %lo(__kernel_image_size_no_bss+15),gr4
236 srli.p gr4,#4,gr4 ; count
237 or gr26,gr26,gr16 ; source
238
239 sethi.p %hi(__sdram_base),gr17 ; destination
240 setlo %lo(__sdram_base),gr17
241
242 setlos #8,gr5
243 sub.p gr16,gr5,gr16 ; adjust src for LDDU
244 sub gr17,gr5,gr17 ; adjust dst for LDDU
245
246 sethi.p %hi(__head_move_kernel-__head_reference),gr18
247 setlo %lo(__head_move_kernel-__head_reference),gr18
248 sethi.p %hi(__head_kernel_moved-__head_reference+__sdram_base),gr19
249 setlo %lo(__head_kernel_moved-__head_reference+__sdram_base),gr19
250 add gr18,gr26,gr18
251 icpl gr18,gr0,#1
252 jmpl @(gr18,gr0)
253
254 .balign 32
255__head_move_kernel:
256 lddu @(gr16,gr5),gr10
257 lddu @(gr16,gr5),gr12
258 stdu.p gr10,@(gr17,gr5)
259 subicc gr4,#1,gr4,icc0
260 stdu.p gr12,@(gr17,gr5)
261 bhi icc0,#0,__head_move_kernel
262 jmpl @(gr19,gr0)
263
264 .balign 32
265__head_kernel_moved:
266 icul gr18
267 icei @(gr0,gr0),1
268 dcei @(gr0,gr0),1
269
270 LEDS 0x0006
271
272 # recalculate reference address
273 call 0f
2740: movsg lr,gr26
275 addi gr26,#__head_reference-0b,gr26
276
277
278###############################################################################
279#
280# rearrange the iomem map and set the protection registers
281#
282###############################################################################
283
284#ifdef CONFIG_MMU
285 LEDS 0x3301
286 call __head_fr451_set_busctl
287 LEDS 0x3303
288 call __head_fr451_survey_sdram
289 LEDS 0x3305
290 call __head_fr451_set_protection
291
292#else
293 movsg psr,gr5
294 srli gr5,#PSR_IMPLE_SHIFT,gr5
295 subicc gr5,#PSR_IMPLE_FR551,gr0,icc0
296 beq icc0,#0,__head_fr555_memmap
297 subicc gr5,#PSR_IMPLE_FR451,gr0,icc0
298 beq icc0,#0,__head_fr451_memmap
299
300 LEDS 0x3101
301 call __head_fr401_set_busctl
302 LEDS 0x3103
303 call __head_fr401_survey_sdram
304 LEDS 0x3105
305 call __head_fr401_set_protection
306 bra __head_done_memmap
307
308__head_fr451_memmap:
309 LEDS 0x3301
310 call __head_fr401_set_busctl
311 LEDS 0x3303
312 call __head_fr401_survey_sdram
313 LEDS 0x3305
314 call __head_fr451_set_protection
315 bra __head_done_memmap
316
317__head_fr555_memmap:
318 LEDS 0x3501
319 call __head_fr555_set_busctl
320 LEDS 0x3503
321 call __head_fr555_survey_sdram
322 LEDS 0x3505
323 call __head_fr555_set_protection
324
325__head_done_memmap:
326#endif
327 LEDS 0x0007
328
329###############################################################################
330#
331# turn the data cache and MMU on
332# - for the FR451 this'll mean that the window through which the kernel is
333# viewed will change
334#
335###############################################################################
336
337#ifdef CONFIG_MMU
338#define MMUMODE HSR0_EIMMU|HSR0_EDMMU|HSR0_EXMMU|HSR0_EDAT|HSR0_XEDAT
339#else
340#define MMUMODE HSR0_EIMMU|HSR0_EDMMU
341#endif
342
343 movsg hsr0,gr5
344
345 sethi.p %hi(MMUMODE),gr4
346 setlo %lo(MMUMODE),gr4
347 or gr4,gr5,gr5
348
349#if defined(CONFIG_FRV_DEFL_CACHE_WTHRU)
350 sethi.p %hi(HSR0_DCE|HSR0_CBM_WRITE_THRU),gr4
351 setlo %lo(HSR0_DCE|HSR0_CBM_WRITE_THRU),gr4
352#elif defined(CONFIG_FRV_DEFL_CACHE_WBACK)
353 sethi.p %hi(HSR0_DCE|HSR0_CBM_COPY_BACK),gr4
354 setlo %lo(HSR0_DCE|HSR0_CBM_COPY_BACK),gr4
355#elif defined(CONFIG_FRV_DEFL_CACHE_WBEHIND)
356 sethi.p %hi(HSR0_DCE|HSR0_CBM_COPY_BACK),gr4
357 setlo %lo(HSR0_DCE|HSR0_CBM_COPY_BACK),gr4
358
359 movsg psr,gr6
360 srli gr6,#24,gr6
361 cmpi gr6,#0x50,icc0 // FR451
362 beq icc0,#0,0f
363 cmpi gr6,#0x40,icc0 // FR405
364 bne icc0,#0,1f
3650:
366 # turn off write-allocate
367 sethi.p %hi(HSR0_NWA),gr6
368 setlo %lo(HSR0_NWA),gr6
369 or gr4,gr6,gr4
3701:
371
372#else
373#error No default cache configuration set
374#endif
375
376 or gr4,gr5,gr5
377 movgs gr5,hsr0
378 bar
379
380 LEDS 0x0008
381
382 sethi.p %hi(__head_mmu_enabled),gr19
383 setlo %lo(__head_mmu_enabled),gr19
384 jmpl @(gr19,gr0)
385
386__head_mmu_enabled:
387 icei @(gr0,gr0),#1
388 dcei @(gr0,gr0),#1
389
390 LEDS 0x0009
391
392#ifdef CONFIG_MMU
393 call __head_fr451_finalise_protection
394#endif
395
396 LEDS 0x000a
397
398###############################################################################
399#
400# set up the runtime environment
401#
402###############################################################################
403
404 # clear the BSS area
405 sethi.p %hi(__bss_start),gr4
406 setlo %lo(__bss_start),gr4
407 sethi.p %hi(_end),gr5
408 setlo %lo(_end),gr5
409 or.p gr0,gr0,gr18
410 or gr0,gr0,gr19
411
4120:
413 stdi gr18,@(gr4,#0)
414 stdi gr18,@(gr4,#8)
415 stdi gr18,@(gr4,#16)
416 stdi.p gr18,@(gr4,#24)
417 addi gr4,#24,gr4
418 subcc gr5,gr4,gr0,icc0
419 bhi icc0,#2,0b
420
421 LEDS 0x000b
422
423 # save the SDRAM details
424 sethi.p %hi(__sdram_old_base),gr4
425 setlo %lo(__sdram_old_base),gr4
426 st gr24,@(gr4,gr0)
427
428 sethi.p %hi(__sdram_base),gr5
429 setlo %lo(__sdram_base),gr5
430 sethi.p %hi(memory_start),gr4
431 setlo %lo(memory_start),gr4
432 st gr5,@(gr4,gr0)
433
434 add gr25,gr5,gr25
435 sethi.p %hi(memory_end),gr4
436 setlo %lo(memory_end),gr4
437 st gr25,@(gr4,gr0)
438
439 # point the TBR at the kernel trap table
440 sethi.p %hi(__entry_kerneltrap_table),gr4
441 setlo %lo(__entry_kerneltrap_table),gr4
442 movgs gr4,tbr
443
444 # set up the exception frame for init
445 sethi.p %hi(__kernel_frame0_ptr),gr28
446 setlo %lo(__kernel_frame0_ptr),gr28
447 sethi.p %hi(_gp),gr16
448 setlo %lo(_gp),gr16
449 sethi.p %hi(__entry_usertrap_table),gr4
450 setlo %lo(__entry_usertrap_table),gr4
451
452 lddi @(gr28,#0),gr28 ; load __frame & current
453 ldi.p @(gr29,#4),gr15 ; set current_thread
454
455 or gr0,gr0,fp
456 or gr28,gr0,sp
457
458 sti.p gr4,@(gr28,REG_TBR)
459 setlos #ISR_EDE|ISR_DTT_DIVBYZERO|ISR_EMAM_EXCEPTION,gr5
460 movgs gr5,isr
461
462 # turn on and off various CPU services
463 movsg psr,gr22
464 sethi.p %hi(#PSR_EM|PSR_EF|PSR_CM|PSR_NEM),gr4
465 setlo %lo(#PSR_EM|PSR_EF|PSR_CM|PSR_NEM),gr4
466 or gr22,gr4,gr22
467 movgs gr22,psr
468
469 andi gr22,#~(PSR_PIL|PSR_PS|PSR_S),gr22
470 ori gr22,#PSR_ET,gr22
471 sti gr22,@(gr28,REG_PSR)
472
473
474###############################################################################
475#
476# set up the registers and jump into the kernel
477#
478###############################################################################
479
480 LEDS 0x000c
481
482 sethi.p #0xe5e5,gr3
483 setlo #0xe5e5,gr3
484 or.p gr3,gr0,gr4
485 or gr3,gr0,gr5
486 or.p gr3,gr0,gr6
487 or gr3,gr0,gr7
488 or.p gr3,gr0,gr8
489 or gr3,gr0,gr9
490 or.p gr3,gr0,gr10
491 or gr3,gr0,gr11
492 or.p gr3,gr0,gr12
493 or gr3,gr0,gr13
494 or.p gr3,gr0,gr14
495 or gr3,gr0,gr17
496 or.p gr3,gr0,gr18
497 or gr3,gr0,gr19
498 or.p gr3,gr0,gr20
499 or gr3,gr0,gr21
500 or.p gr3,gr0,gr23
501 or gr3,gr0,gr24
502 or.p gr3,gr0,gr25
503 or gr3,gr0,gr26
504 or.p gr3,gr0,gr27
505# or gr3,gr0,gr30
506 or gr3,gr0,gr31
507 movgs gr0,lr
508 movgs gr0,lcr
509 movgs gr0,ccr
510 movgs gr0,cccr
511
512 # initialise the virtual interrupt handling
513 subcc gr0,gr0,gr0,icc2 /* set Z, clear C */
514
515#ifdef CONFIG_MMU
516 movgs gr3,scr2
517 movgs gr3,scr3
518#endif
519
520 LEDS 0x0fff
521
522 # invoke the debugging stub if present
523 # - arch/frv/kernel/debug-stub.c will shift control directly to init/main.c
524 # (it will not return here)
525 break
526 .globl __debug_stub_init_break
527__debug_stub_init_break:
528
529 # however, if you need to use an ICE, and don't care about using any userspace
530 # debugging tools (such as the ptrace syscall), you can just step over the break
531 # above and get to the kernel this way
532 # look at arch/frv/kernel/debug-stub.c: debug_stub_init() to see what you've missed
533 call start_kernel
534
535 .globl __head_end
536__head_end:
537 .size _boot, .-_boot
538
539 # provide a point for GDB to place a break
540 .section .text..start,"ax"
541 .globl _start
542 .balign 4
543_start:
544 call _boot
545
546 .previous
547###############################################################################
548#
549# split a tile off of the region defined by GR8-GR9
550#
551# ENTRY: EXIT:
552# GR4 - IAMPR value representing tile
553# GR5 - DAMPR value representing tile
554# GR6 - IAMLR value representing tile
555# GR7 - DAMLR value representing tile
556# GR8 region base pointer [saved]
557# GR9 region top pointer updated to exclude new tile
558# GR11 xAMLR mask [saved]
559# GR25 SDRAM size [saved]
560# GR30 LED address [saved]
561#
562# - GR8 and GR9 should be rounded up/down to the nearest megabyte before calling
563#
564###############################################################################
565 .globl __head_split_region
566 .type __head_split_region,@function
567__head_split_region:
568 subcc.p gr9,gr8,gr4,icc0
569 setlos #31,gr5
570 scan.p gr4,gr0,gr6
571 beq icc0,#0,__head_region_empty
572 sub.p gr5,gr6,gr6 ; bit number of highest set bit (1MB=>20)
573 setlos #1,gr4
574 sll.p gr4,gr6,gr4 ; size of region (1 << bitno)
575 subi gr6,#17,gr6 ; 1MB => 0x03
576 slli.p gr6,#4,gr6 ; 1MB => 0x30
577 sub gr9,gr4,gr9 ; move uncovered top down
578
579 or gr9,gr6,gr4
580 ori gr4,#xAMPRx_S_USER|xAMPRx_C_CACHED|xAMPRx_V,gr4
581 or.p gr4,gr0,gr5
582
583 and gr4,gr11,gr6
584 and.p gr5,gr11,gr7
585 bralr
586
587__head_region_empty:
588 or.p gr0,gr0,gr4
589 or gr0,gr0,gr5
590 or.p gr0,gr0,gr6
591 or gr0,gr0,gr7
592 bralr
593 .size __head_split_region, .-__head_split_region
594
595###############################################################################
596#
597# write the 32-bit hex number in GR8 to ttyS0
598#
599###############################################################################
600#if 0
601 .globl __head_write_to_ttyS0
602 .type __head_write_to_ttyS0,@function
603__head_write_to_ttyS0:
604 sethi.p %hi(0xfeff9c00),gr31
605 setlo %lo(0xfeff9c00),gr31
606 setlos #8,gr20
607
6080: ldubi @(gr31,#5*8),gr21
609 andi gr21,#0x60,gr21
610 subicc gr21,#0x60,gr21,icc0
611 bne icc0,#0,0b
612
6131: srli gr8,#28,gr21
614 slli gr8,#4,gr8
615
616 addi gr21,#'0',gr21
617 subicc gr21,#'9',gr0,icc0
618 bls icc0,#2,2f
619 addi gr21,#'A'-'0'-10,gr21
6202:
621 stbi gr21,@(gr31,#0*8)
622 subicc gr20,#1,gr20,icc0
623 bhi icc0,#2,1b
624
625 setlos #'\r',gr21
626 stbi gr21,@(gr31,#0*8)
627
628 setlos #'\n',gr21
629 stbi gr21,@(gr31,#0*8)
630
6313: ldubi @(gr31,#5*8),gr21
632 andi gr21,#0x60,gr21
633 subicc gr21,#0x60,gr21,icc0
634 bne icc0,#0,3b
635 bralr
636
637 .size __head_write_to_ttyS0, .-__head_write_to_ttyS0
638#endif