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v4.17
  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * head.S: The initial boot code for the Sparc port of Linux.
  4 *
  5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
  6 * Copyright (C) 1995,1999 Pete Zaitcev   (zaitcev@yahoo.com)
  7 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
  8 * Copyright (C) 1997 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
  9 * Copyright (C) 1997 Michael A. Griffith (grif@acm.org)
 10 *
 11 * CompactPCI platform by Eric Brower, 1999.
 12 */
 13
 
 14#include <linux/version.h>
 15#include <linux/init.h>
 16
 17#include <asm/head.h>
 18#include <asm/asi.h>
 19#include <asm/contregs.h>
 20#include <asm/ptrace.h>
 21#include <asm/psr.h>
 22#include <asm/page.h>
 23#include <asm/kdebug.h>
 24#include <asm/winmacro.h>
 25#include <asm/thread_info.h>	/* TI_UWINMASK */
 26#include <asm/errno.h>
 27#include <asm/pgtsrmmu.h>	/* SRMMU_PGDIR_SHIFT */
 28#include <asm/export.h>
 29
 30	.data
 31/* The following are used with the prom_vector node-ops to figure out
 32 * the cpu-type
 33 */
 34	.align 4
 35	.globl cputypval
 36cputypval:
 37	.asciz "sun4m"
 38	.ascii "     "
 39
 40/* Tested on SS-5, SS-10 */
 41	.align 4
 42cputypvar:
 43	.asciz "compatible"
 44
 45	.align 4
 46
 47notsup:
 48	.asciz	"Sparc-Linux sun4/sun4c or MMU-less not supported\n\n"
 49	.align 4
 50
 51sun4e_notsup:
 52        .asciz  "Sparc-Linux sun4e support does not exist\n\n"
 53	.align 4
 54
 55/* The trap-table - located in the __HEAD section */
 56#include "ttable_32.S"
 57
 58	.align PAGE_SIZE
 59
 60/* This was the only reasonable way I could think of to properly align
 61 * these page-table data structures.
 62 */
 63	.globl empty_zero_page
 64empty_zero_page:	.skip PAGE_SIZE
 65EXPORT_SYMBOL(empty_zero_page)
 66
 67	.global root_flags
 68	.global ram_flags
 69	.global root_dev
 70	.global sparc_ramdisk_image
 71	.global sparc_ramdisk_size
 72
 73/* This stuff has to be in sync with SILO and other potential boot loaders
 74 * Fields should be kept upward compatible and whenever any change is made,
 75 * HdrS version should be incremented.
 76 */
 77	.ascii	"HdrS"
 78	.word	LINUX_VERSION_CODE
 79	.half	0x0203		/* HdrS version */
 80root_flags:
 81	.half	1
 82root_dev:
 83	.half	0
 84ram_flags:
 85	.half	0
 86sparc_ramdisk_image:
 87	.word	0
 88sparc_ramdisk_size:
 89	.word	0
 90	.word	reboot_command
 91	.word	0, 0, 0
 92	.word	_end
 93
 94/* Cool, here we go. Pick up the romvec pointer in %o0 and stash it in
 95 * %g7 and at prom_vector_p. And also quickly check whether we are on
 96 * a v0, v2, or v3 prom.
 97 */
 98gokernel:
 99		/* Ok, it's nice to know, as early as possible, if we
100		 * are already mapped where we expect to be in virtual
101		 * memory.  The Solaris /boot elf format bootloader
102		 * will peek into our elf header and load us where
103		 * we want to be, otherwise we have to re-map.
104		 *
105		 * Some boot loaders don't place the jmp'rs address
106		 * in %o7, so we do a pc-relative call to a local
107		 * label, then see what %o7 has.
108		 */
109
110		mov	%o7, %g4		! Save %o7
111
112		/* Jump to it, and pray... */
113current_pc:
114		call	1f
115		 nop
116
1171:
118		mov	%o7, %g3
119
120		tst	%o0
121		be	no_sun4u_here
122		 mov	%g4, %o7		/* Previous %o7. */
123
 
 
 
124		mov	%o0, %l0		! stash away romvec
125		mov	%o0, %g7		! put it here too
126		mov	%o1, %l1		! stash away debug_vec too
127
128		/* Ok, let's check out our run time program counter. */
129		set	current_pc, %g5
130		cmp	%g3, %g5
131		be	already_mapped
132		 nop
133
134		/* %l6 will hold the offset we have to subtract
135		 * from absolute symbols in order to access areas
136		 * in our own image.  If already mapped this is
137		 * just plain zero, else it is KERNBASE.
138		 */
139		set	KERNBASE, %l6
140		b	copy_prom_lvl14
141		 nop
142
143already_mapped:
144		mov	0, %l6
145
146		/* Copy over the Prom's level 14 clock handler. */
147copy_prom_lvl14:
148#if 1
149		/* DJHR
150		 * preserve our linked/calculated instructions
151		 */
152		set	lvl14_save, %g1
153		set	t_irq14, %g3
154		sub	%g1, %l6, %g1		! translate to physical
155		sub	%g3, %l6, %g3		! translate to physical
156		ldd	[%g3], %g4
157		std	%g4, [%g1]
158		ldd	[%g3+8], %g4
159		std	%g4, [%g1+8]
160#endif
161		rd	%tbr, %g1
162		andn	%g1, 0xfff, %g1		! proms trap table base
163		or	%g0, (0x1e<<4), %g2	! offset to lvl14 intr
164		or	%g1, %g2, %g2
165		set	t_irq14, %g3
166		sub	%g3, %l6, %g3
167		ldd	[%g2], %g4
168		std	%g4, [%g3]
169		ldd	[%g2 + 0x8], %g4
170		std	%g4, [%g3 + 0x8]	! Copy proms handler
171
172/* DON'T TOUCH %l0 thru %l5 in these remapping routines,
173 * we need their values afterwards!
174 */
175
176		/* Now check whether we are already mapped, if we
177		 * are we can skip all this garbage coming up.
178		 */
179copy_prom_done:
180		cmp	%l6, 0
181		be	go_to_highmem		! this will be a nop then
182		 nop
183
184		/* Validate that we are in fact running on an
185		 * SRMMU based cpu.
186		 */
187		set	0x4000, %g6
188		cmp	%g7, %g6
189		bne	not_a_sun4
190		 nop
191
192halt_notsup:
193		ld	[%g7 + 0x68], %o1
194		set	notsup, %o0
195		sub	%o0, %l6, %o0
196		call	%o1
197		 nop
198		ba	halt_me
 
199		 nop
200
201not_a_sun4:
202		/* It looks like this is a machine we support.
203		 * Now find out what MMU we are dealing with
204		 * LEON - identified by the psr.impl field
205		 * Viking - identified by the psr.impl field
206		 * In all other cases a sun4m srmmu.
207		 * We check that the MMU is enabled in all cases.
208		 */
209
210		/* Check if this is a LEON CPU */
211		rd	%psr, %g3
212		srl	%g3, PSR_IMPL_SHIFT, %g3
213		and	%g3, PSR_IMPL_SHIFTED_MASK, %g3
214		cmp	%g3, PSR_IMPL_LEON
215		be	leon_remap		/* It is a LEON - jump */
216		 nop
217
218		/* Sanity-check, is MMU enabled */
219		lda	[%g0] ASI_M_MMUREGS, %g1
220		andcc	%g1, 1, %g0
221		be	halt_notsup
222		 nop
223
224		/* Check for a viking (TI) module. */
225		cmp	%g3, PSR_IMPL_TI
226		bne	srmmu_not_viking
227		 nop
228
229		/* Figure out what kind of viking we are on.
230		 * We need to know if we have to play with the
231		 * AC bit and disable traps or not.
232		 */
233
234		/* I've only seen MicroSparc's on SparcClassics with this
235		 * bit set.
236		 */
237		set	0x800, %g2
238		lda	[%g0] ASI_M_MMUREGS, %g3	! peek in the control reg
239		and	%g2, %g3, %g3
240		subcc	%g3, 0x0, %g0
241		bnz	srmmu_not_viking			! is in mbus mode
242		 nop
243
244		rd	%psr, %g3			! DO NOT TOUCH %g3
245		andn	%g3, PSR_ET, %g2
246		wr	%g2, 0x0, %psr
247		WRITE_PAUSE
248
249		/* Get context table pointer, then convert to
250		 * a physical address, which is 36 bits.
251		 */
252		set	AC_M_CTPR, %g4
253		lda	[%g4] ASI_M_MMUREGS, %g4
254		sll	%g4, 0x4, %g4			! We use this below
255							! DO NOT TOUCH %g4
256
257		/* Set the AC bit in the Viking's MMU control reg. */
258		lda	[%g0] ASI_M_MMUREGS, %g5	! DO NOT TOUCH %g5
259		set	0x8000, %g6			! AC bit mask
260		or	%g5, %g6, %g6			! Or it in...
261		sta	%g6, [%g0] ASI_M_MMUREGS	! Close your eyes...
262
263		/* Grrr, why does it seem like every other load/store
264		 * on the sun4m is in some ASI space...
265		 * Fine with me, let's get the pointer to the level 1
266		 * page table directory and fetch its entry.
267		 */
268		lda	[%g4] ASI_M_BYPASS, %o1		! This is a level 1 ptr
269		srl	%o1, 0x4, %o1			! Clear low 4 bits
270		sll	%o1, 0x8, %o1			! Make physical
271
272		/* Ok, pull in the PTD. */
273		lda	[%o1] ASI_M_BYPASS, %o2		! This is the 0x0 16MB pgd
274
275		/* Calculate to KERNBASE entry. */
276		add	%o1, KERNBASE >> (SRMMU_PGDIR_SHIFT - 2), %o3
277
278		/* Poke the entry into the calculated address. */
279		sta	%o2, [%o3] ASI_M_BYPASS
280
281		/* I don't get it Sun, if you engineered all these
282		 * boot loaders and the PROM (thank you for the debugging
283		 * features btw) why did you not have them load kernel
284		 * images up in high address space, since this is necessary
285		 * for ABI compliance anyways?  Does this low-mapping provide
286		 * enhanced interoperability?
287		 *
288		 * "The PROM is the computer."
289		 */
290
291		/* Ok, restore the MMU control register we saved in %g5 */
292		sta	%g5, [%g0] ASI_M_MMUREGS	! POW... ouch
293
294		/* Turn traps back on.  We saved it in %g3 earlier. */
295		wr	%g3, 0x0, %psr			! tick tock, tick tock
296
297		/* Now we burn precious CPU cycles due to bad engineering. */
298		WRITE_PAUSE
299
300		/* Wow, all that just to move a 32-bit value from one
301		 * place to another...  Jump to high memory.
302		 */
303		b	go_to_highmem
304		 nop
305
306srmmu_not_viking:
307		/* This works on viking's in Mbus mode and all
308		 * other MBUS modules.  It is virtually the same as
309		 * the above madness sans turning traps off and flipping
310		 * the AC bit.
311		 */
312		set	AC_M_CTPR, %g1
313		lda	[%g1] ASI_M_MMUREGS, %g1	! get ctx table ptr
314		sll	%g1, 0x4, %g1			! make physical addr
315		lda	[%g1] ASI_M_BYPASS, %g1		! ptr to level 1 pg_table
316		srl	%g1, 0x4, %g1
317		sll	%g1, 0x8, %g1			! make phys addr for l1 tbl
318
319		lda	[%g1] ASI_M_BYPASS, %g2		! get level1 entry for 0x0
320		add	%g1, KERNBASE >> (SRMMU_PGDIR_SHIFT - 2), %g3
321		sta	%g2, [%g3] ASI_M_BYPASS		! place at KERNBASE entry
322		b	go_to_highmem
323		 nop					! wheee....
324
325
326leon_remap:
327		/* Sanity-check, is MMU enabled */
328		lda	[%g0] ASI_LEON_MMUREGS, %g1
329		andcc	%g1, 1, %g0
330		be	halt_notsup
331		 nop
332
333		/* Same code as in the srmmu_not_viking case,
334		 * with the LEON ASI for mmuregs
335		 */
336		set	AC_M_CTPR, %g1
337		lda	[%g1] ASI_LEON_MMUREGS, %g1	! get ctx table ptr
338		sll	%g1, 0x4, %g1			! make physical addr
339		lda	[%g1] ASI_M_BYPASS, %g1		! ptr to level 1 pg_table
340		srl	%g1, 0x4, %g1
341		sll	%g1, 0x8, %g1			! make phys addr for l1 tbl
342
343		lda	[%g1] ASI_M_BYPASS, %g2		! get level1 entry for 0x0
344		add	%g1, KERNBASE >> (SRMMU_PGDIR_SHIFT - 2), %g3
345		sta	%g2, [%g3] ASI_M_BYPASS		! place at KERNBASE entry
346		b	go_to_highmem
347		 nop					! wheee....
348
349/* Now do a non-relative jump so that PC is in high-memory */
350go_to_highmem:
351		set	execute_in_high_mem, %g1
352		jmpl	%g1, %g0
353		 nop
354
355/* The code above should be at beginning and we have to take care about
356 * short jumps, as branching to .init.text section from .text is usually
357 * impossible */
358		__INIT
359/* Acquire boot time privileged register values, this will help debugging.
360 * I figure out and store nwindows and nwindowsm1 later on.
361 */
362execute_in_high_mem:
363		mov	%l0, %o0		! put back romvec
364		mov	%l1, %o1		! and debug_vec
365
366		sethi	%hi(prom_vector_p), %g1
367		st	%o0, [%g1 + %lo(prom_vector_p)]
368
369		sethi	%hi(linux_dbvec), %g1
370		st	%o1, [%g1 + %lo(linux_dbvec)]
371
372		/* Get the machine type via the romvec
373		 * getprops node operation
374		 */
375		add	%g7, 0x1c, %l1
376		ld	[%l1], %l0
377		ld	[%l0], %l0
378		call	%l0
379		 or	%g0, %g0, %o0		! next_node(0) = first_node
380		or	%o0, %g0, %g6
381
382		sethi	%hi(cputypvar), %o1	! First node has cpu-arch
383		or	%o1, %lo(cputypvar), %o1
384		sethi	%hi(cputypval), %o2	! information, the string
385		or	%o2, %lo(cputypval), %o2
386		ld	[%l1], %l0		! 'compatible' tells
387		ld	[%l0 + 0xc], %l0	! that we want 'sun4x' where
388		call	%l0			! x is one of 'm', 'd' or 'e'.
389		 nop				! %o2 holds pointer
390						! to a buf where above string
391						! will get stored by the prom.
392
393
394		/* Check value of "compatible" property.
395		 * "value" => "model"
396		 * leon => sparc_leon
397		 * sun4m => sun4m
398		 * sun4s => sun4m
399		 * sun4d => sun4d
400		 * sun4e => "no_sun4e_here"
401		 * '*'   => "no_sun4u_here"
402		 * Check single letters only
403		 */
404
405		set	cputypval, %o2
406		/* If cputypval[0] == 'l' (lower case letter L) this is leon */
407		ldub	[%o2], %l1
408		cmp	%l1, 'l'
409		be	leon_init
410		 nop
411
412		/* Check cputypval[4] to find the sun model */
413		ldub	[%o2 + 0x4], %l1
414
415		cmp	%l1, 'm'
416		be	sun4m_init
417		 cmp	%l1, 's'
418		be	sun4m_init
419		 cmp	%l1, 'd'
420		be	sun4d_init
421		 cmp	%l1, 'e'
422		be	no_sun4e_here		! Could be a sun4e.
423		 nop
424		b	no_sun4u_here		! AIEEE, a V9 sun4u... Get our BIG BROTHER kernel :))
425		 nop
426
427leon_init:
428		/* LEON CPU - set boot_cpu_id */
429		sethi	%hi(boot_cpu_id), %g2	! boot-cpu index
430
431#ifdef CONFIG_SMP
432		ldub	[%g2 + %lo(boot_cpu_id)], %g1
433		cmp	%g1, 0xff		! unset means first CPU
434		bne	leon_smp_cpu_startup	! continue only with master
 
 
435		 nop
 
436#endif
437		/* Get CPU-ID from most significant 4-bit of ASR17 */
438		rd     %asr17, %g1
439		srl    %g1, 28, %g1
440
441		/* Update boot_cpu_id only on boot cpu */
442		stub	%g1, [%g2 + %lo(boot_cpu_id)]
443
444		ba continue_boot
445		 nop
446
447/* CPUID in bootbus can be found at PA 0xff0140000 */
448#define SUN4D_BOOTBUS_CPUID     0xf0140000
449
450sun4d_init:
451	/* Need to patch call to handler_irq */
452	set	patch_handler_irq, %g4
453	set	sun4d_handler_irq, %g5
454	sethi	%hi(0x40000000), %g3		! call
455	sub	%g5, %g4, %g5
456	srl	%g5, 2, %g5
457	or	%g5, %g3, %g5
458	st	%g5, [%g4]
459
460#ifdef CONFIG_SMP
461	/* Get our CPU id out of bootbus */
462	set     SUN4D_BOOTBUS_CPUID, %g3
463	lduba   [%g3] ASI_M_CTL, %g3
464	and     %g3, 0xf8, %g3
465	srl     %g3, 3, %g4
466	sta     %g4, [%g0] ASI_M_VIKING_TMP1
467	sethi	%hi(boot_cpu_id), %g5
468	stb	%g4, [%g5 + %lo(boot_cpu_id)]
469#endif
470
471	/* Fall through to sun4m_init */
472
473sun4m_init:
474/* Ok, the PROM could have done funny things and apple cider could still
475 * be sitting in the fault status/address registers.  Read them all to
476 * clear them so we don't get magic faults later on.
477 */
478/* This sucks, apparently this makes Vikings call prom panic, will fix later */
4792:
480		rd	%psr, %o1
481		srl	%o1, PSR_IMPL_SHIFT, %o1	! Get a type of the CPU
482
483		subcc	%o1, PSR_IMPL_TI, %g0		! TI: Viking or MicroSPARC
484		be	continue_boot
485		 nop
486
487		set	AC_M_SFSR, %o0
488		lda	[%o0] ASI_M_MMUREGS, %g0
489		set	AC_M_SFAR, %o0
490		lda	[%o0] ASI_M_MMUREGS, %g0
491
492		/* Fujitsu MicroSPARC-II has no asynchronous flavors of FARs */
493		subcc	%o1, 0, %g0
494		be	continue_boot
495		 nop
496
497		set	AC_M_AFSR, %o0
498		lda	[%o0] ASI_M_MMUREGS, %g0
499		set	AC_M_AFAR, %o0
500		lda	[%o0] ASI_M_MMUREGS, %g0
501		 nop
502
503
504continue_boot:
505
506/* Aieee, now set PC and nPC, enable traps, give ourselves a stack and it's
507 * show-time!
508 */
509		/* Turn on Supervisor, EnableFloating, and all the PIL bits.
510		 * Also puts us in register window zero with traps off.
511		 */
512		set	(PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2
513		wr	%g2, 0x0, %psr
514		WRITE_PAUSE
515
516		/* I want a kernel stack NOW! */
517		set	init_thread_union, %g1
518		set	(THREAD_SIZE - STACKFRAME_SZ), %g2
519		add	%g1, %g2, %sp
520		mov	0, %fp			/* And for good luck */
521
522		/* Zero out our BSS section. */
523		set	__bss_start , %o0	! First address of BSS
524		set	_end , %o1		! Last address of BSS
525		add	%o0, 0x1, %o0
5261:
527		stb	%g0, [%o0]
528		subcc	%o0, %o1, %g0
529		bl	1b
530		 add	%o0, 0x1, %o0
531
532		/* If boot_cpu_id has not been setup by machine specific
533		 * init-code above we default it to zero.
534		 */
535		sethi	%hi(boot_cpu_id), %g2
536		ldub	[%g2 + %lo(boot_cpu_id)], %g3
537		cmp	%g3, 0xff
538		bne	1f
539		 nop
540		mov	%g0, %g3
541		stub	%g3, [%g2 + %lo(boot_cpu_id)]
542
5431:		sll	%g3, 2, %g3
544
545		/* Initialize the uwinmask value for init task just in case.
546		 * But first make current_set[boot_cpu_id] point to something useful.
547		 */
548		set	init_thread_union, %g6
549		set	current_set, %g2
550#ifdef CONFIG_SMP
551		st	%g6, [%g2]
552		add	%g2, %g3, %g2
553#endif
554		st	%g6, [%g2]
555
556		st	%g0, [%g6 + TI_UWINMASK]
557
558/* Compute NWINDOWS and stash it away. Now uses %wim trick explained
559 * in the V8 manual. Ok, this method seems to work, Sparc is cool...
560 * No, it doesn't work, have to play the save/readCWP/restore trick.
561 */
562
563		wr	%g0, 0x0, %wim			! so we do not get a trap
564		WRITE_PAUSE
565
566		save
567
568		rd	%psr, %g3
569
570		restore
571
572		and	%g3, 0x1f, %g3
573		add	%g3, 0x1, %g3
574
575		mov	2, %g1
576		wr	%g1, 0x0, %wim			! make window 1 invalid
577		WRITE_PAUSE
578
579		cmp	%g3, 0x7
580		bne	2f
581		 nop
582
583		/* Adjust our window handling routines to
584		 * do things correctly on 7 window Sparcs.
585		 */
586
587#define		PATCH_INSN(src, dest) \
588		set	src, %g5; \
589		set	dest, %g2; \
590		ld	[%g5], %g4; \
591		st	%g4, [%g2];
592
593		/* Patch for window spills... */
594		PATCH_INSN(spnwin_patch1_7win, spnwin_patch1)
595		PATCH_INSN(spnwin_patch2_7win, spnwin_patch2)
596		PATCH_INSN(spnwin_patch3_7win, spnwin_patch3)
597
598		/* Patch for window fills... */
599		PATCH_INSN(fnwin_patch1_7win, fnwin_patch1)
600		PATCH_INSN(fnwin_patch2_7win, fnwin_patch2)
601
602		/* Patch for trap entry setup... */
603		PATCH_INSN(tsetup_7win_patch1, tsetup_patch1)
604		PATCH_INSN(tsetup_7win_patch2, tsetup_patch2)
605		PATCH_INSN(tsetup_7win_patch3, tsetup_patch3)
606		PATCH_INSN(tsetup_7win_patch4, tsetup_patch4)
607		PATCH_INSN(tsetup_7win_patch5, tsetup_patch5)
608		PATCH_INSN(tsetup_7win_patch6, tsetup_patch6)
609
610		/* Patch for returning from traps... */
611		PATCH_INSN(rtrap_7win_patch1, rtrap_patch1)
612		PATCH_INSN(rtrap_7win_patch2, rtrap_patch2)
613		PATCH_INSN(rtrap_7win_patch3, rtrap_patch3)
614		PATCH_INSN(rtrap_7win_patch4, rtrap_patch4)
615		PATCH_INSN(rtrap_7win_patch5, rtrap_patch5)
616
617		/* Patch for killing user windows from the register file. */
618		PATCH_INSN(kuw_patch1_7win, kuw_patch1)
619
620		/* Now patch the kernel window flush sequences.
621		 * This saves 2 traps on every switch and fork.
622		 */
623		set	0x01000000, %g4
624		set	flush_patch_one, %g5
625		st	%g4, [%g5 + 0x18]
626		st	%g4, [%g5 + 0x1c]
627		set	flush_patch_two, %g5
628		st	%g4, [%g5 + 0x18]
629		st	%g4, [%g5 + 0x1c]
630		set	flush_patch_three, %g5
631		st	%g4, [%g5 + 0x18]
632		st	%g4, [%g5 + 0x1c]
633		set	flush_patch_four, %g5
634		st	%g4, [%g5 + 0x18]
635		st	%g4, [%g5 + 0x1c]
636		set	flush_patch_exception, %g5
637		st	%g4, [%g5 + 0x18]
638		st	%g4, [%g5 + 0x1c]
639		set	flush_patch_switch, %g5
640		st	%g4, [%g5 + 0x18]
641		st	%g4, [%g5 + 0x1c]
642
6432:
644		sethi	%hi(nwindows), %g4
645		st	%g3, [%g4 + %lo(nwindows)]	! store final value
646		sub	%g3, 0x1, %g3
647		sethi	%hi(nwindowsm1), %g4
648		st	%g3, [%g4 + %lo(nwindowsm1)]
649
650		/* Here we go, start using Linux's trap table... */
651		set	trapbase, %g3
652		wr	%g3, 0x0, %tbr
653		WRITE_PAUSE
654
655		/* Finally, turn on traps so that we can call c-code. */
656		rd	%psr, %g3
657		wr	%g3, 0x0, %psr
658		WRITE_PAUSE
659
660		wr	%g3, PSR_ET, %psr
661		WRITE_PAUSE
662
663		/* Call sparc32_start_kernel(struct linux_romvec *rp) */
664		sethi	%hi(prom_vector_p), %g5
665		ld	[%g5 + %lo(prom_vector_p)], %o0
666		call	sparc32_start_kernel
667		 nop
668
669		/* We should not get here. */
670		call	halt_me
671		 nop
672
673no_sun4e_here:
674		ld	[%g7 + 0x68], %o1
675		set	sun4e_notsup, %o0
676		call	%o1
677		 nop
678		b	halt_me
679		 nop
680
681		__INITDATA
682
683sun4u_1:
684		.asciz "finddevice"
685		.align	4
686sun4u_2:
687		.asciz "/chosen"
688		.align	4
689sun4u_3:
690		.asciz "getprop"
691		.align	4
692sun4u_4:
693		.asciz "stdout"
694		.align	4
695sun4u_5:
696		.asciz "write"
697		.align	4
698sun4u_6:
699		.asciz  "\n\rOn sun4u you have to use sparc64 kernel\n\rand not a sparc32 version\n\r\n\r"
700sun4u_6e:
701		.align	4
702sun4u_7:
703		.asciz "exit"
704		.align	8
705sun4u_a1:
706		.word	0, sun4u_1, 0, 1, 0, 1, 0, sun4u_2, 0
707sun4u_r1:
708		.word	0
709sun4u_a2:
710		.word	0, sun4u_3, 0, 4, 0, 1, 0
711sun4u_i2:
712		.word	0, 0, sun4u_4, 0, sun4u_1, 0, 8, 0
713sun4u_r2:
714		.word	0
715sun4u_a3:
716		.word	0, sun4u_5, 0, 3, 0, 1, 0
717sun4u_i3:
718		.word	0, 0, sun4u_6, 0, sun4u_6e - sun4u_6 - 1, 0
719sun4u_r3:
720		.word	0
721sun4u_a4:
722		.word	0, sun4u_7, 0, 0, 0, 0
723sun4u_r4:
724
725		__INIT
726no_sun4u_here:
727		set	sun4u_a1, %o0
728		set	current_pc, %l2
729		cmp	%l2, %g3
730		be	1f
731		 mov	%o4, %l0
732		sub	%g3, %l2, %l6
733		add	%o0, %l6, %o0
734		mov	%o0, %l4
735		mov	sun4u_r4 - sun4u_a1, %l3
736		ld	[%l4], %l5
7372:
738		add	%l4, 4, %l4
739		cmp	%l5, %l2
740		add	%l5, %l6, %l5
741		bgeu,a	3f
742		 st	%l5, [%l4 - 4]
7433:
744		subcc	%l3, 4, %l3
745		bne	2b
746		 ld	[%l4], %l5
7471:
748		call	%l0
749		 mov	%o0, %l1
750
751		ld	[%l1 + (sun4u_r1 - sun4u_a1)], %o1
752		add	%l1, (sun4u_a2 - sun4u_a1), %o0
753		call	%l0
754		 st	%o1, [%o0 + (sun4u_i2 - sun4u_a2)]
755
756		ld	[%l1 + (sun4u_1 - sun4u_a1)], %o1
757		add	%l1, (sun4u_a3 - sun4u_a1), %o0
758		call	%l0
759		st	%o1, [%o0 + (sun4u_i3 - sun4u_a3)]
760
761		call	%l0
762		 add	%l1, (sun4u_a4 - sun4u_a1), %o0
763
764		/* Not reached */
765halt_me:
766		ld	[%g7 + 0x74], %o0
767		call	%o0			! Get us out of here...
768		 nop				! Apparently Solaris is better.
769
770/* Ok, now we continue in the .data/.text sections */
771
772	.data
773	.align 4
774
775/*
776 * Fill up the prom vector, note in particular the kind first element,
777 * no joke. I don't need all of them in here as the entire prom vector
778 * gets initialized in c-code so all routines can use it.
779 */
780
781prom_vector_p:
782		.word 0
783
784/* We calculate the following at boot time, window fills/spills and trap entry
785 * code uses these to keep track of the register windows.
786 */
787
788	.align 4
789	.globl	nwindows
790	.globl	nwindowsm1
791nwindows:
792	.word	8
793nwindowsm1:
794	.word	7
795
796/* Boot time debugger vector value.  We need this later on. */
797
798	.align 4
799	.globl	linux_dbvec
800linux_dbvec:
801	.word	0
802	.word	0
803
804	.align 8
805
806	.globl	lvl14_save
807lvl14_save:
808	.word	0
809	.word	0
810	.word	0
811	.word	0
812	.word	t_irq14
v6.13.7
  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * head.S: The initial boot code for the Sparc port of Linux.
  4 *
  5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
  6 * Copyright (C) 1995,1999 Pete Zaitcev   (zaitcev@yahoo.com)
  7 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
  8 * Copyright (C) 1997 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
  9 * Copyright (C) 1997 Michael A. Griffith (grif@acm.org)
 10 *
 11 * CompactPCI platform by Eric Brower, 1999.
 12 */
 13
 14#include <linux/export.h>
 15#include <linux/version.h>
 16#include <linux/init.h>
 17
 18#include <asm/head.h>
 19#include <asm/asi.h>
 20#include <asm/contregs.h>
 21#include <asm/ptrace.h>
 22#include <asm/psr.h>
 23#include <asm/page.h>
 24#include <asm/kdebug.h>
 25#include <asm/winmacro.h>
 26#include <asm/thread_info.h>	/* TI_UWINMASK */
 27#include <asm/errno.h>
 28#include <asm/pgtable.h>	/* PGDIR_SHIFT */
 
 29
 30	.data
 31/* The following are used with the prom_vector node-ops to figure out
 32 * the cpu-type
 33 */
 34	.align 4
 35	.globl cputypval
 36cputypval:
 37	.asciz "sun4m"
 38	.ascii "     "
 39
 40/* Tested on SS-5, SS-10 */
 41	.align 4
 42cputypvar:
 43	.asciz "compatible"
 44
 45	.align 4
 46
 47notsup:
 48	.asciz	"Sparc-Linux sun4/sun4c or MMU-less not supported\n\n"
 49	.align 4
 50
 51sun4e_notsup:
 52        .asciz  "Sparc-Linux sun4e support does not exist\n\n"
 53	.align 4
 54
 55/* The trap-table - located in the __HEAD section */
 56#include "ttable_32.S"
 57
 58	.align PAGE_SIZE
 59
 60/* This was the only reasonable way I could think of to properly align
 61 * these page-table data structures.
 62 */
 63	.globl empty_zero_page
 64empty_zero_page:	.skip PAGE_SIZE
 65EXPORT_SYMBOL(empty_zero_page)
 66
 67	.global root_flags
 68	.global ram_flags
 69	.global root_dev
 70	.global sparc_ramdisk_image
 71	.global sparc_ramdisk_size
 72
 73/* This stuff has to be in sync with SILO and other potential boot loaders
 74 * Fields should be kept upward compatible and whenever any change is made,
 75 * HdrS version should be incremented.
 76 */
 77	.ascii	"HdrS"
 78	.word	LINUX_VERSION_CODE
 79	.half	0x0203		/* HdrS version */
 80root_flags:
 81	.half	1
 82root_dev:
 83	.half	0
 84ram_flags:
 85	.half	0
 86sparc_ramdisk_image:
 87	.word	0
 88sparc_ramdisk_size:
 89	.word	0
 90	.word	reboot_command
 91	.word	0, 0, 0
 92	.word	_end
 93
 94/* Cool, here we go. Pick up the romvec pointer in %o0 and stash it in
 95 * %g7 and at prom_vector_p. And also quickly check whether we are on
 96 * a v0, v2, or v3 prom.
 97 */
 98gokernel:
 99		/* Ok, it's nice to know, as early as possible, if we
100		 * are already mapped where we expect to be in virtual
101		 * memory.  The Solaris /boot elf format bootloader
102		 * will peek into our elf header and load us where
103		 * we want to be, otherwise we have to re-map.
104		 *
105		 * Some boot loaders don't place the jmp'rs address
106		 * in %o7, so we do a pc-relative call to a local
107		 * label, then see what %o7 has.
108		 */
109
110		mov	%o7, %g4		! Save %o7
111
112		/* Jump to it, and pray... */
113current_pc:
114		call	1f
115		 nop
116
1171:
118		mov	%o7, %g3
119
120		tst	%o0
121		bne	2f
122		 mov	%g4, %o7		/* Previous %o7. */
123		sethi	%hi(no_sun4u_here), %l1
124		jmpl	%l1 + %lo(no_sun4u_here), %g0
125		 nop
1262:
127		mov	%o0, %l0		! stash away romvec
128		mov	%o0, %g7		! put it here too
129		mov	%o1, %l1		! stash away debug_vec too
130
131		/* Ok, let's check out our run time program counter. */
132		set	current_pc, %g5
133		cmp	%g3, %g5
134		be	already_mapped
135		 nop
136
137		/* %l6 will hold the offset we have to subtract
138		 * from absolute symbols in order to access areas
139		 * in our own image.  If already mapped this is
140		 * just plain zero, else it is KERNBASE.
141		 */
142		set	KERNBASE, %l6
143		b	copy_prom_lvl14
144		 nop
145
146already_mapped:
147		mov	0, %l6
148
149		/* Copy over the Prom's level 14 clock handler. */
150copy_prom_lvl14:
151#if 1
152		/* DJHR
153		 * preserve our linked/calculated instructions
154		 */
155		set	lvl14_save, %g1
156		set	t_irq14, %g3
157		sub	%g1, %l6, %g1		! translate to physical
158		sub	%g3, %l6, %g3		! translate to physical
159		ldd	[%g3], %g4
160		std	%g4, [%g1]
161		ldd	[%g3+8], %g4
162		std	%g4, [%g1+8]
163#endif
164		rd	%tbr, %g1
165		andn	%g1, 0xfff, %g1		! proms trap table base
166		or	%g0, (0x1e<<4), %g2	! offset to lvl14 intr
167		or	%g1, %g2, %g2
168		set	t_irq14, %g3
169		sub	%g3, %l6, %g3
170		ldd	[%g2], %g4
171		std	%g4, [%g3]
172		ldd	[%g2 + 0x8], %g4
173		std	%g4, [%g3 + 0x8]	! Copy proms handler
174
175/* DON'T TOUCH %l0 thru %l5 in these remapping routines,
176 * we need their values afterwards!
177 */
178
179		/* Now check whether we are already mapped, if we
180		 * are we can skip all this garbage coming up.
181		 */
182copy_prom_done:
183		cmp	%l6, 0
184		be	go_to_highmem		! this will be a nop then
185		 nop
186
187		/* Validate that we are in fact running on an
188		 * SRMMU based cpu.
189		 */
190		set	0x4000, %g6
191		cmp	%g7, %g6
192		bne	not_a_sun4
193		 nop
194
195halt_notsup:
196		ld	[%g7 + 0x68], %o1
197		set	notsup, %o0
198		sub	%o0, %l6, %o0
199		call	%o1
200		 nop
201		sethi	%hi(halt_me), %o0
202		jmpl	%o0 + %lo(halt_me), %g0
203		 nop
204
205not_a_sun4:
206		/* It looks like this is a machine we support.
207		 * Now find out what MMU we are dealing with
208		 * LEON - identified by the psr.impl field
209		 * Viking - identified by the psr.impl field
210		 * In all other cases a sun4m srmmu.
211		 * We check that the MMU is enabled in all cases.
212		 */
213
214		/* Check if this is a LEON CPU */
215		rd	%psr, %g3
216		srl	%g3, PSR_IMPL_SHIFT, %g3
217		and	%g3, PSR_IMPL_SHIFTED_MASK, %g3
218		cmp	%g3, PSR_IMPL_LEON
219		be	leon_remap		/* It is a LEON - jump */
220		 nop
221
222		/* Sanity-check, is MMU enabled */
223		lda	[%g0] ASI_M_MMUREGS, %g1
224		andcc	%g1, 1, %g0
225		be	halt_notsup
226		 nop
227
228		/* Check for a viking (TI) module. */
229		cmp	%g3, PSR_IMPL_TI
230		bne	srmmu_not_viking
231		 nop
232
233		/* Figure out what kind of viking we are on.
234		 * We need to know if we have to play with the
235		 * AC bit and disable traps or not.
236		 */
237
238		/* I've only seen MicroSparc's on SparcClassics with this
239		 * bit set.
240		 */
241		set	0x800, %g2
242		lda	[%g0] ASI_M_MMUREGS, %g3	! peek in the control reg
243		and	%g2, %g3, %g3
244		subcc	%g3, 0x0, %g0
245		bnz	srmmu_not_viking			! is in mbus mode
246		 nop
247
248		rd	%psr, %g3			! DO NOT TOUCH %g3
249		andn	%g3, PSR_ET, %g2
250		wr	%g2, 0x0, %psr
251		WRITE_PAUSE
252
253		/* Get context table pointer, then convert to
254		 * a physical address, which is 36 bits.
255		 */
256		set	AC_M_CTPR, %g4
257		lda	[%g4] ASI_M_MMUREGS, %g4
258		sll	%g4, 0x4, %g4			! We use this below
259							! DO NOT TOUCH %g4
260
261		/* Set the AC bit in the Viking's MMU control reg. */
262		lda	[%g0] ASI_M_MMUREGS, %g5	! DO NOT TOUCH %g5
263		set	0x8000, %g6			! AC bit mask
264		or	%g5, %g6, %g6			! Or it in...
265		sta	%g6, [%g0] ASI_M_MMUREGS	! Close your eyes...
266
267		/* Grrr, why does it seem like every other load/store
268		 * on the sun4m is in some ASI space...
269		 * Fine with me, let's get the pointer to the level 1
270		 * page table directory and fetch its entry.
271		 */
272		lda	[%g4] ASI_M_BYPASS, %o1		! This is a level 1 ptr
273		srl	%o1, 0x4, %o1			! Clear low 4 bits
274		sll	%o1, 0x8, %o1			! Make physical
275
276		/* Ok, pull in the PTD. */
277		lda	[%o1] ASI_M_BYPASS, %o2		! This is the 0x0 16MB pgd
278
279		/* Calculate to KERNBASE entry. */
280		add	%o1, KERNBASE >> (PGDIR_SHIFT - 2), %o3
281
282		/* Poke the entry into the calculated address. */
283		sta	%o2, [%o3] ASI_M_BYPASS
284
285		/* I don't get it Sun, if you engineered all these
286		 * boot loaders and the PROM (thank you for the debugging
287		 * features btw) why did you not have them load kernel
288		 * images up in high address space, since this is necessary
289		 * for ABI compliance anyways?  Does this low-mapping provide
290		 * enhanced interoperability?
291		 *
292		 * "The PROM is the computer."
293		 */
294
295		/* Ok, restore the MMU control register we saved in %g5 */
296		sta	%g5, [%g0] ASI_M_MMUREGS	! POW... ouch
297
298		/* Turn traps back on.  We saved it in %g3 earlier. */
299		wr	%g3, 0x0, %psr			! tick tock, tick tock
300
301		/* Now we burn precious CPU cycles due to bad engineering. */
302		WRITE_PAUSE
303
304		/* Wow, all that just to move a 32-bit value from one
305		 * place to another...  Jump to high memory.
306		 */
307		b	go_to_highmem
308		 nop
309
310srmmu_not_viking:
311		/* This works on viking's in Mbus mode and all
312		 * other MBUS modules.  It is virtually the same as
313		 * the above madness sans turning traps off and flipping
314		 * the AC bit.
315		 */
316		set	AC_M_CTPR, %g1
317		lda	[%g1] ASI_M_MMUREGS, %g1	! get ctx table ptr
318		sll	%g1, 0x4, %g1			! make physical addr
319		lda	[%g1] ASI_M_BYPASS, %g1		! ptr to level 1 pg_table
320		srl	%g1, 0x4, %g1
321		sll	%g1, 0x8, %g1			! make phys addr for l1 tbl
322
323		lda	[%g1] ASI_M_BYPASS, %g2		! get level1 entry for 0x0
324		add	%g1, KERNBASE >> (PGDIR_SHIFT - 2), %g3
325		sta	%g2, [%g3] ASI_M_BYPASS		! place at KERNBASE entry
326		b	go_to_highmem
327		 nop					! wheee....
328
329
330leon_remap:
331		/* Sanity-check, is MMU enabled */
332		lda	[%g0] ASI_LEON_MMUREGS, %g1
333		andcc	%g1, 1, %g0
334		be	halt_notsup
335		 nop
336
337		/* Same code as in the srmmu_not_viking case,
338		 * with the LEON ASI for mmuregs
339		 */
340		set	AC_M_CTPR, %g1
341		lda	[%g1] ASI_LEON_MMUREGS, %g1	! get ctx table ptr
342		sll	%g1, 0x4, %g1			! make physical addr
343		lda	[%g1] ASI_M_BYPASS, %g1		! ptr to level 1 pg_table
344		srl	%g1, 0x4, %g1
345		sll	%g1, 0x8, %g1			! make phys addr for l1 tbl
346
347		lda	[%g1] ASI_M_BYPASS, %g2		! get level1 entry for 0x0
348		add	%g1, KERNBASE >> (PGDIR_SHIFT - 2), %g3
349		sta	%g2, [%g3] ASI_M_BYPASS		! place at KERNBASE entry
350		b	go_to_highmem
351		 nop					! wheee....
352
353/* Now do a non-relative jump so that PC is in high-memory */
354go_to_highmem:
355		set	execute_in_high_mem, %g1
356		jmpl	%g1, %g0
357		 nop
358
359/* The code above should be at beginning and we have to take care about
360 * short jumps, as branching to .init.text section from .text is usually
361 * impossible */
362		__INIT
363/* Acquire boot time privileged register values, this will help debugging.
364 * I figure out and store nwindows and nwindowsm1 later on.
365 */
366execute_in_high_mem:
367		mov	%l0, %o0		! put back romvec
368		mov	%l1, %o1		! and debug_vec
369
370		sethi	%hi(prom_vector_p), %g1
371		st	%o0, [%g1 + %lo(prom_vector_p)]
372
373		sethi	%hi(linux_dbvec), %g1
374		st	%o1, [%g1 + %lo(linux_dbvec)]
375
376		/* Get the machine type via the romvec
377		 * getprops node operation
378		 */
379		add	%g7, 0x1c, %l1
380		ld	[%l1], %l0
381		ld	[%l0], %l0
382		call	%l0
383		 or	%g0, %g0, %o0		! next_node(0) = first_node
384		or	%o0, %g0, %g6
385
386		sethi	%hi(cputypvar), %o1	! First node has cpu-arch
387		or	%o1, %lo(cputypvar), %o1
388		sethi	%hi(cputypval), %o2	! information, the string
389		or	%o2, %lo(cputypval), %o2
390		ld	[%l1], %l0		! 'compatible' tells
391		ld	[%l0 + 0xc], %l0	! that we want 'sun4x' where
392		call	%l0			! x is one of 'm', 'd' or 'e'.
393		 nop				! %o2 holds pointer
394						! to a buf where above string
395						! will get stored by the prom.
396
397
398		/* Check value of "compatible" property.
399		 * "value" => "model"
400		 * leon => sparc_leon
401		 * sun4m => sun4m
402		 * sun4s => sun4m
403		 * sun4d => sun4d
404		 * sun4e => "no_sun4e_here"
405		 * '*'   => "no_sun4u_here"
406		 * Check single letters only
407		 */
408
409		set	cputypval, %o2
410		/* If cputypval[0] == 'l' (lower case letter L) this is leon */
411		ldub	[%o2], %l1
412		cmp	%l1, 'l'
413		be	leon_init
414		 nop
415
416		/* Check cputypval[4] to find the sun model */
417		ldub	[%o2 + 0x4], %l1
418
419		cmp	%l1, 'm'
420		be	sun4m_init
421		 cmp	%l1, 's'
422		be	sun4m_init
423		 cmp	%l1, 'd'
424		be	sun4d_init
425		 cmp	%l1, 'e'
426		be	no_sun4e_here		! Could be a sun4e.
427		 nop
428		b	no_sun4u_here		! AIEEE, a V9 sun4u... Get our BIG BROTHER kernel :))
429		 nop
430
431leon_init:
432		/* LEON CPU - set boot_cpu_id */
433		sethi	%hi(boot_cpu_id), %g2	! boot-cpu index
434
435#ifdef CONFIG_SMP
436		ldub	[%g2 + %lo(boot_cpu_id)], %g1
437		cmp	%g1, 0xff		! unset means first CPU
438		be 1f
439		 sethi	%hi(leon_smp_cpu_startup), %g1
440		jmpl	%g1 + %lo(leon_smp_cpu_startup), %g0
441		 nop
4421:
443#endif
444		/* Get CPU-ID from most significant 4-bit of ASR17 */
445		rd     %asr17, %g1
446		srl    %g1, 28, %g1
447
448		/* Update boot_cpu_id only on boot cpu */
449		stub	%g1, [%g2 + %lo(boot_cpu_id)]
450
451		ba continue_boot
452		 nop
453
454/* CPUID in bootbus can be found at PA 0xff0140000 */
455#define SUN4D_BOOTBUS_CPUID     0xf0140000
456
457sun4d_init:
458	/* Need to patch call to handler_irq */
459	set	patch_handler_irq, %g4
460	set	sun4d_handler_irq, %g5
461	sethi	%hi(0x40000000), %g3		! call
462	sub	%g5, %g4, %g5
463	srl	%g5, 2, %g5
464	or	%g5, %g3, %g5
465	st	%g5, [%g4]
466
467#ifdef CONFIG_SMP
468	/* Get our CPU id out of bootbus */
469	set     SUN4D_BOOTBUS_CPUID, %g3
470	lduba   [%g3] ASI_M_CTL, %g3
471	and     %g3, 0xf8, %g3
472	srl     %g3, 3, %g4
473	sta     %g4, [%g0] ASI_M_VIKING_TMP1
474	sethi	%hi(boot_cpu_id), %g5
475	stb	%g4, [%g5 + %lo(boot_cpu_id)]
476#endif
477
478	/* Fall through to sun4m_init */
479
480sun4m_init:
481/* Ok, the PROM could have done funny things and apple cider could still
482 * be sitting in the fault status/address registers.  Read them all to
483 * clear them so we don't get magic faults later on.
484 */
485/* This sucks, apparently this makes Vikings call prom panic, will fix later */
4862:
487		rd	%psr, %o1
488		srl	%o1, PSR_IMPL_SHIFT, %o1	! Get a type of the CPU
489
490		subcc	%o1, PSR_IMPL_TI, %g0		! TI: Viking or MicroSPARC
491		be	continue_boot
492		 nop
493
494		set	AC_M_SFSR, %o0
495		lda	[%o0] ASI_M_MMUREGS, %g0
496		set	AC_M_SFAR, %o0
497		lda	[%o0] ASI_M_MMUREGS, %g0
498
499		/* Fujitsu MicroSPARC-II has no asynchronous flavors of FARs */
500		subcc	%o1, 0, %g0
501		be	continue_boot
502		 nop
503
504		set	AC_M_AFSR, %o0
505		lda	[%o0] ASI_M_MMUREGS, %g0
506		set	AC_M_AFAR, %o0
507		lda	[%o0] ASI_M_MMUREGS, %g0
508		 nop
509
510
511continue_boot:
512
513/* Aieee, now set PC and nPC, enable traps, give ourselves a stack and it's
514 * show-time!
515 */
516		/* Turn on Supervisor, EnableFloating, and all the PIL bits.
517		 * Also puts us in register window zero with traps off.
518		 */
519		set	(PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2
520		wr	%g2, 0x0, %psr
521		WRITE_PAUSE
522
523		/* I want a kernel stack NOW! */
524		set	init_thread_union, %g1
525		set	(THREAD_SIZE - STACKFRAME_SZ - TRACEREG_SZ), %g2
526		add	%g1, %g2, %sp
527		mov	0, %fp			/* And for good luck */
528
529		/* Zero out our BSS section. */
530		set	__bss_start , %o0	! First address of BSS
531		set	_end , %o1		! Last address of BSS
532		add	%o0, 0x1, %o0
5331:
534		stb	%g0, [%o0]
535		subcc	%o0, %o1, %g0
536		bl	1b
537		 add	%o0, 0x1, %o0
538
539		/* If boot_cpu_id has not been setup by machine specific
540		 * init-code above we default it to zero.
541		 */
542		sethi	%hi(boot_cpu_id), %g2
543		ldub	[%g2 + %lo(boot_cpu_id)], %g3
544		cmp	%g3, 0xff
545		bne	1f
546		 nop
547		mov	%g0, %g3
548		stub	%g3, [%g2 + %lo(boot_cpu_id)]
549
5501:		sll	%g3, 2, %g3
551
552		/* Initialize the uwinmask value for init task just in case.
553		 * But first make current_set[boot_cpu_id] point to something useful.
554		 */
555		set	init_thread_union, %g6
556		set	current_set, %g2
557#ifdef CONFIG_SMP
558		st	%g6, [%g2]
559		add	%g2, %g3, %g2
560#endif
561		st	%g6, [%g2]
562
563		st	%g0, [%g6 + TI_UWINMASK]
564
565/* Compute NWINDOWS and stash it away. Now uses %wim trick explained
566 * in the V8 manual. Ok, this method seems to work, Sparc is cool...
567 * No, it doesn't work, have to play the save/readCWP/restore trick.
568 */
569
570		wr	%g0, 0x0, %wim			! so we do not get a trap
571		WRITE_PAUSE
572
573		save
574
575		rd	%psr, %g3
576
577		restore
578
579		and	%g3, 0x1f, %g3
580		add	%g3, 0x1, %g3
581
582		mov	2, %g1
583		wr	%g1, 0x0, %wim			! make window 1 invalid
584		WRITE_PAUSE
585
586		cmp	%g3, 0x7
587		bne	2f
588		 nop
589
590		/* Adjust our window handling routines to
591		 * do things correctly on 7 window Sparcs.
592		 */
593
594#define		PATCH_INSN(src, dest) \
595		set	src, %g5; \
596		set	dest, %g2; \
597		ld	[%g5], %g4; \
598		st	%g4, [%g2];
599
600		/* Patch for window spills... */
601		PATCH_INSN(spnwin_patch1_7win, spnwin_patch1)
602		PATCH_INSN(spnwin_patch2_7win, spnwin_patch2)
603		PATCH_INSN(spnwin_patch3_7win, spnwin_patch3)
604
605		/* Patch for window fills... */
606		PATCH_INSN(fnwin_patch1_7win, fnwin_patch1)
607		PATCH_INSN(fnwin_patch2_7win, fnwin_patch2)
608
609		/* Patch for trap entry setup... */
610		PATCH_INSN(tsetup_7win_patch1, tsetup_patch1)
611		PATCH_INSN(tsetup_7win_patch2, tsetup_patch2)
612		PATCH_INSN(tsetup_7win_patch3, tsetup_patch3)
613		PATCH_INSN(tsetup_7win_patch4, tsetup_patch4)
614		PATCH_INSN(tsetup_7win_patch5, tsetup_patch5)
615		PATCH_INSN(tsetup_7win_patch6, tsetup_patch6)
616
617		/* Patch for returning from traps... */
618		PATCH_INSN(rtrap_7win_patch1, rtrap_patch1)
619		PATCH_INSN(rtrap_7win_patch2, rtrap_patch2)
620		PATCH_INSN(rtrap_7win_patch3, rtrap_patch3)
621		PATCH_INSN(rtrap_7win_patch4, rtrap_patch4)
622		PATCH_INSN(rtrap_7win_patch5, rtrap_patch5)
623
624		/* Patch for killing user windows from the register file. */
625		PATCH_INSN(kuw_patch1_7win, kuw_patch1)
626
627		/* Now patch the kernel window flush sequences.
628		 * This saves 2 traps on every switch and fork.
629		 */
630		set	0x01000000, %g4
631		set	flush_patch_one, %g5
632		st	%g4, [%g5 + 0x18]
633		st	%g4, [%g5 + 0x1c]
634		set	flush_patch_two, %g5
635		st	%g4, [%g5 + 0x18]
636		st	%g4, [%g5 + 0x1c]
637		set	flush_patch_three, %g5
638		st	%g4, [%g5 + 0x18]
639		st	%g4, [%g5 + 0x1c]
640		set	flush_patch_four, %g5
641		st	%g4, [%g5 + 0x18]
642		st	%g4, [%g5 + 0x1c]
643		set	flush_patch_exception, %g5
644		st	%g4, [%g5 + 0x18]
645		st	%g4, [%g5 + 0x1c]
646		set	flush_patch_switch, %g5
647		st	%g4, [%g5 + 0x18]
648		st	%g4, [%g5 + 0x1c]
649
6502:
651		sethi	%hi(nwindows), %g4
652		st	%g3, [%g4 + %lo(nwindows)]	! store final value
653		sub	%g3, 0x1, %g3
654		sethi	%hi(nwindowsm1), %g4
655		st	%g3, [%g4 + %lo(nwindowsm1)]
656
657		/* Here we go, start using Linux's trap table... */
658		set	trapbase, %g3
659		wr	%g3, 0x0, %tbr
660		WRITE_PAUSE
661
662		/* Finally, turn on traps so that we can call c-code. */
663		rd	%psr, %g3
664		wr	%g3, 0x0, %psr
665		WRITE_PAUSE
666
667		wr	%g3, PSR_ET, %psr
668		WRITE_PAUSE
669
670		/* Call sparc32_start_kernel(struct linux_romvec *rp) */
671		sethi	%hi(prom_vector_p), %g5
672		ld	[%g5 + %lo(prom_vector_p)], %o0
673		call	sparc32_start_kernel
674		 nop
675
676		/* We should not get here. */
677		call	halt_me
678		 nop
679
680no_sun4e_here:
681		ld	[%g7 + 0x68], %o1
682		set	sun4e_notsup, %o0
683		call	%o1
684		 nop
685		b	halt_me
686		 nop
687
688		__INITDATA
689
690sun4u_1:
691		.asciz "finddevice"
692		.align	4
693sun4u_2:
694		.asciz "/chosen"
695		.align	4
696sun4u_3:
697		.asciz "getprop"
698		.align	4
699sun4u_4:
700		.asciz "stdout"
701		.align	4
702sun4u_5:
703		.asciz "write"
704		.align	4
705sun4u_6:
706		.asciz  "\n\rOn sun4u you have to use sparc64 kernel\n\rand not a sparc32 version\n\r\n\r"
707sun4u_6e:
708		.align	4
709sun4u_7:
710		.asciz "exit"
711		.align	8
712sun4u_a1:
713		.word	0, sun4u_1, 0, 1, 0, 1, 0, sun4u_2, 0
714sun4u_r1:
715		.word	0
716sun4u_a2:
717		.word	0, sun4u_3, 0, 4, 0, 1, 0
718sun4u_i2:
719		.word	0, 0, sun4u_4, 0, sun4u_1, 0, 8, 0
720sun4u_r2:
721		.word	0
722sun4u_a3:
723		.word	0, sun4u_5, 0, 3, 0, 1, 0
724sun4u_i3:
725		.word	0, 0, sun4u_6, 0, sun4u_6e - sun4u_6 - 1, 0
726sun4u_r3:
727		.word	0
728sun4u_a4:
729		.word	0, sun4u_7, 0, 0, 0, 0
730sun4u_r4:
731
732		__INIT
733no_sun4u_here:
734		set	sun4u_a1, %o0
735		set	current_pc, %l2
736		cmp	%l2, %g3
737		be	1f
738		 mov	%o4, %l0
739		sub	%g3, %l2, %l6
740		add	%o0, %l6, %o0
741		mov	%o0, %l4
742		mov	sun4u_r4 - sun4u_a1, %l3
743		ld	[%l4], %l5
7442:
745		add	%l4, 4, %l4
746		cmp	%l5, %l2
747		add	%l5, %l6, %l5
748		bgeu,a	3f
749		 st	%l5, [%l4 - 4]
7503:
751		subcc	%l3, 4, %l3
752		bne	2b
753		 ld	[%l4], %l5
7541:
755		call	%l0
756		 mov	%o0, %l1
757
758		ld	[%l1 + (sun4u_r1 - sun4u_a1)], %o1
759		add	%l1, (sun4u_a2 - sun4u_a1), %o0
760		call	%l0
761		 st	%o1, [%o0 + (sun4u_i2 - sun4u_a2)]
762
763		ld	[%l1 + (sun4u_1 - sun4u_a1)], %o1
764		add	%l1, (sun4u_a3 - sun4u_a1), %o0
765		call	%l0
766		st	%o1, [%o0 + (sun4u_i3 - sun4u_a3)]
767
768		call	%l0
769		 add	%l1, (sun4u_a4 - sun4u_a1), %o0
770
771		/* Not reached */
772halt_me:
773		ld	[%g7 + 0x74], %o0
774		call	%o0			! Get us out of here...
775		 nop				! Apparently Solaris is better.
776
777/* Ok, now we continue in the .data/.text sections */
778
779	.data
780	.align 4
781
782/*
783 * Fill up the prom vector, note in particular the kind first element,
784 * no joke. I don't need all of them in here as the entire prom vector
785 * gets initialized in c-code so all routines can use it.
786 */
787
788prom_vector_p:
789		.word 0
790
791/* We calculate the following at boot time, window fills/spills and trap entry
792 * code uses these to keep track of the register windows.
793 */
794
795	.align 4
796	.globl	nwindows
797	.globl	nwindowsm1
798nwindows:
799	.word	8
800nwindowsm1:
801	.word	7
802
803/* Boot time debugger vector value.  We need this later on. */
804
805	.align 4
806	.globl	linux_dbvec
807linux_dbvec:
808	.word	0
809	.word	0
810
811	.align 8
812
813	.globl	lvl14_save
814lvl14_save:
815	.word	0
816	.word	0
817	.word	0
818	.word	0
819	.word	t_irq14