1/*
2 *  armboot - Startup Code for ARM926EJS CPU-core
3 *
4 *  Copyright (c) 2003  Texas Instruments
5 *
6 *  ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
7 *
8 *  Copyright (c) 2001	Marius Gr�ger <mag@sysgo.de>
9 *  Copyright (c) 2002	Alex Z�pke <azu@sysgo.de>
10 *  Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
11 *  Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
12 *  Copyright (c) 2003	Kshitij <kshitij@ti.com>
13 *
14 * See file CREDITS for list of people who contributed to this
15 * project.
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License as
19 * published by the Free Software Foundation; either version 2 of
20 * the License, or (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25 * GNU General Public License for more details.
26 *
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
30 * MA 02111-1307 USA
31 */
32
33
34#include <config.h>
35#include <common.h>
36#include <version.h>
37
38#if defined(CONFIG_OMAP1610)
39#include <./configs/omap1510.h>
40#elif defined(CONFIG_OMAP730)
41#include <./configs/omap730.h>
42#endif
43
44/*
45 *************************************************************************
46 *
47 * Jump vector table as in table 3.1 in [1]
48 *
49 *************************************************************************
50 */
51
52
53.globl _start
54_start:
55	b	reset
56#ifdef CONFIG_PRELOADER
57/* No exception handlers in preloader */
58	ldr	pc, _hang
59	ldr	pc, _hang
60	ldr	pc, _hang
61	ldr	pc, _hang
62	ldr	pc, _hang
63	ldr	pc, _hang
64	ldr	pc, _hang
65
66_hang:
67	.word	do_hang
68/* pad to 64 byte boundary */
69	.word	0x12345678
70	.word	0x12345678
71	.word	0x12345678
72	.word	0x12345678
73	.word	0x12345678
74	.word	0x12345678
75	.word	0x12345678
76#else
77	ldr	pc, _undefined_instruction
78	ldr	pc, _software_interrupt
79	ldr	pc, _prefetch_abort
80	ldr	pc, _data_abort
81	ldr	pc, _not_used
82	ldr	pc, _irq
83	ldr	pc, _fiq
84
85_undefined_instruction:
86	.word undefined_instruction
87_software_interrupt:
88	.word software_interrupt
89_prefetch_abort:
90	.word prefetch_abort
91_data_abort:
92	.word data_abort
93_not_used:
94	.word not_used
95_irq:
96	.word irq
97_fiq:
98	.word fiq
99
100#endif	/* CONFIG_PRELOADER */
101	.balignl 16,0xdeadbeef
102
103
104/*
105 *************************************************************************
106 *
107 * Startup Code (reset vector)
108 *
109 * do important init only if we don't start from memory!
110 * setup Memory and board specific bits prior to relocation.
111 * relocate armboot to ram
112 * setup stack
113 *
114 *************************************************************************
115 */
116
117_TEXT_BASE:
118	.word	TEXT_BASE
119
120.globl _armboot_start
121_armboot_start:
122	.word _start
123
124/*
125 * These are defined in the board-specific linker script.
126 */
127.globl _bss_start
128_bss_start:
129	.word __bss_start
130
131.globl _bss_end
132_bss_end:
133	.word _end
134
135#ifdef CONFIG_USE_IRQ
136/* IRQ stack memory (calculated at run-time) */
137.globl IRQ_STACK_START
138IRQ_STACK_START:
139	.word	0x0badc0de
140
141/* IRQ stack memory (calculated at run-time) */
142.globl FIQ_STACK_START
143FIQ_STACK_START:
144	.word 0x0badc0de
145#endif
146
147
148/*
149 * the actual reset code
150 */
151
152reset:
153	/*
154	 * set the cpu to SVC32 mode
155	 */
156	mrs	r0,cpsr
157	bic	r0,r0,#0x1f
158	orr	r0,r0,#0xd3
159	msr	cpsr,r0
160
161	/*
162	 * we do sys-critical inits only at reboot,
163	 * not when booting from ram!
164	 */
165#ifndef CONFIG_SKIP_LOWLEVEL_INIT
166	bl	cpu_init_crit
167#endif
168
169#ifndef CONFIG_SKIP_RELOCATE_UBOOT
170relocate:				/* relocate U-Boot to RAM	    */
171	adr	r0, _start		/* r0 <- current position of code   */
172	ldr	r1, _TEXT_BASE		/* test if we run from flash or RAM */
173	cmp     r0, r1                  /* don't reloc during debug         */
174	beq     stack_setup
175	ldr	r2, _armboot_start
176	ldr	r3, _bss_start
177	sub	r2, r3, r2		/* r2 <- size of armboot            */
178	add	r2, r0, r2		/* r2 <- source end address         */
179
180copy_loop:
181	ldmia	r0!, {r3-r10}		/* copy from source address [r0]    */
182	stmia	r1!, {r3-r10}		/* copy to   target address [r1]    */
183	cmp	r0, r2			/* until source end addreee [r2]    */
184	ble	copy_loop
185#endif	/* CONFIG_SKIP_RELOCATE_UBOOT */
186
187	/* Set up the stack						    */
188stack_setup:
189	ldr	r0, _TEXT_BASE		/* upper 128 KiB: relocated uboot   */
190	sub	sp, r0, #128		/* leave 32 words for abort-stack   */
191#ifndef CONFIG_PRELOADER
192	sub	r0, r0, #CONFIG_SYS_MALLOC_LEN	/* malloc area                      */
193	sub	r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo                        */
194#ifdef CONFIG_USE_IRQ
195	sub	r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
196#endif
197#endif /* CONFIG_PRELOADER */
198	sub	sp, r0, #12		/* leave 3 words for abort-stack    */
199	bic	sp, sp, #7		/* 8-byte alignment for ABI compliance */
200
201clear_bss:
202	ldr	r0, _bss_start		/* find start of bss segment        */
203	ldr	r1, _bss_end		/* stop here                        */
204	mov	r2, #0x00000000		/* clear                            */
205
206#ifndef CONFIG_PRELOADER
207clbss_l:str	r2, [r0]		/* clear loop...                    */
208	add	r0, r0, #4
209	cmp	r0, r1
210	ble	clbss_l
211
212	bl coloured_LED_init
213	bl red_LED_on
214#endif /* CONFIG_PRELOADER */
215
216	ldr	pc, _start_armboot
217
218_start_armboot:
219#ifdef CONFIG_NAND_SPL
220	.word nand_boot
221#else
222	.word start_armboot
223#endif /* CONFIG_NAND_SPL */
224
225
226/*
227 *************************************************************************
228 *
229 * CPU_init_critical registers
230 *
231 * setup important registers
232 * setup memory timing
233 *
234 *************************************************************************
235 */
236#ifndef CONFIG_SKIP_LOWLEVEL_INIT
237cpu_init_crit:
238	/*
239	 * flush v4 I/D caches
240	 */
241	mov	r0, #0
242	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
243	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
244
245	/*
246	 * disable MMU stuff and caches
247	 */
248	mrc	p15, 0, r0, c1, c0, 0
249	bic	r0, r0, #0x00002300	/* clear bits 13, 9:8 (--V- --RS) */
250	bic	r0, r0, #0x00000087	/* clear bits 7, 2:0 (B--- -CAM) */
251	orr	r0, r0, #0x00000002	/* set bit 2 (A) Align */
252	orr	r0, r0, #0x00001000	/* set bit 12 (I) I-Cache */
253	mcr	p15, 0, r0, c1, c0, 0
254
255	/*
256	 * Go setup Memory and board specific bits prior to relocation.
257	 */
258	mov	ip, lr		/* perserve link reg across call */
259	bl	lowlevel_init	/* go setup pll,mux,memory */
260	mov	lr, ip		/* restore link */
261	mov	pc, lr		/* back to my caller */
262#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
263
264#ifndef CONFIG_PRELOADER
265/*
266 *************************************************************************
267 *
268 * Interrupt handling
269 *
270 *************************************************************************
271 */
272
273@
274@ IRQ stack frame.
275@
276#define S_FRAME_SIZE	72
277
278#define S_OLD_R0	68
279#define S_PSR		64
280#define S_PC		60
281#define S_LR		56
282#define S_SP		52
283
284#define S_IP		48
285#define S_FP		44
286#define S_R10		40
287#define S_R9		36
288#define S_R8		32
289#define S_R7		28
290#define S_R6		24
291#define S_R5		20
292#define S_R4		16
293#define S_R3		12
294#define S_R2		8
295#define S_R1		4
296#define S_R0		0
297
298#define MODE_SVC 0x13
299#define I_BIT	 0x80
300
301/*
302 * use bad_save_user_regs for abort/prefetch/undef/swi ...
303 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
304 */
305
306	.macro	bad_save_user_regs
307	@ carve out a frame on current user stack
308	sub	sp, sp, #S_FRAME_SIZE
309	stmia	sp, {r0 - r12}	@ Save user registers (now in svc mode) r0-r12
310
311	ldr	r2, _armboot_start
312	sub	r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
313	sub	r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8)  @ set base 2 words into abort stack
314	@ get values for "aborted" pc and cpsr (into parm regs)
315	ldmia	r2, {r2 - r3}
316	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
317	add	r5, sp, #S_SP
318	mov	r1, lr
319	stmia	r5, {r0 - r3}	@ save sp_SVC, lr_SVC, pc, cpsr
320	mov	r0, sp		@ save current stack into r0 (param register)
321	.endm
322
323	.macro	irq_save_user_regs
324	sub	sp, sp, #S_FRAME_SIZE
325	stmia	sp, {r0 - r12}			@ Calling r0-r12
326	@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
327	add	r8, sp, #S_PC
328	stmdb	r8, {sp, lr}^		@ Calling SP, LR
329	str	lr, [r8, #0]		@ Save calling PC
330	mrs	r6, spsr
331	str	r6, [r8, #4]		@ Save CPSR
332	str	r0, [r8, #8]		@ Save OLD_R0
333	mov	r0, sp
334	.endm
335
336	.macro	irq_restore_user_regs
337	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
338	mov	r0, r0
339	ldr	lr, [sp, #S_PC]			@ Get PC
340	add	sp, sp, #S_FRAME_SIZE
341	subs	pc, lr, #4		@ return & move spsr_svc into cpsr
342	.endm
343
344	.macro get_bad_stack
345	ldr	r13, _armboot_start		@ setup our mode stack
346	sub	r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
347	sub	r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
348
349	str	lr, [r13]	@ save caller lr in position 0 of saved stack
350	mrs	lr, spsr	@ get the spsr
351	str	lr, [r13, #4]	@ save spsr in position 1 of saved stack
352	mov	r13, #MODE_SVC	@ prepare SVC-Mode
353	@ msr	spsr_c, r13
354	msr	spsr, r13	@ switch modes, make sure moves will execute
355	mov	lr, pc		@ capture return pc
356	movs	pc, lr		@ jump to next instruction & switch modes.
357	.endm
358
359	.macro get_irq_stack			@ setup IRQ stack
360	ldr	sp, IRQ_STACK_START
361	.endm
362
363	.macro get_fiq_stack			@ setup FIQ stack
364	ldr	sp, FIQ_STACK_START
365	.endm
366#endif	/* CONFIG_PRELOADER */
367
368/*
369 * exception handlers
370 */
371#ifdef CONFIG_PRELOADER
372	.align	5
373do_hang:
374	ldr	sp, _TEXT_BASE			/* switch to abort stack */
3751:
376	bl	1b				/* hang and never return */
377#else	/* !CONFIG_PRELOADER */
378	.align  5
379undefined_instruction:
380	get_bad_stack
381	bad_save_user_regs
382	bl	do_undefined_instruction
383
384	.align	5
385software_interrupt:
386	get_bad_stack
387	bad_save_user_regs
388	bl	do_software_interrupt
389
390	.align	5
391prefetch_abort:
392	get_bad_stack
393	bad_save_user_regs
394	bl	do_prefetch_abort
395
396	.align	5
397data_abort:
398	get_bad_stack
399	bad_save_user_regs
400	bl	do_data_abort
401
402	.align	5
403not_used:
404	get_bad_stack
405	bad_save_user_regs
406	bl	do_not_used
407
408#ifdef CONFIG_USE_IRQ
409
410	.align	5
411irq:
412	get_irq_stack
413	irq_save_user_regs
414	bl	do_irq
415	irq_restore_user_regs
416
417	.align	5
418fiq:
419	get_fiq_stack
420	/* someone ought to write a more effiction fiq_save_user_regs */
421	irq_save_user_regs
422	bl	do_fiq
423	irq_restore_user_regs
424
425#else
426
427	.align	5
428irq:
429	get_bad_stack
430	bad_save_user_regs
431	bl	do_irq
432
433	.align	5
434fiq:
435	get_bad_stack
436	bad_save_user_regs
437	bl	do_fiq
438
439#endif
440#endif	/* CONFIG_PRELOADER */
441