xref: /openbmc/u-boot/arch/microblaze/cpu/start.S (revision 9eea50162c6a9bbdd01736984fc939649119f382)
16260fb04SPeter Tyser/*
26260fb04SPeter Tyser * (C) Copyright 2007 Michal Simek
36260fb04SPeter Tyser * (C) Copyright 2004 Atmark Techno, Inc.
46260fb04SPeter Tyser *
56260fb04SPeter Tyser * Michal  SIMEK <monstr@monstr.eu>
66260fb04SPeter Tyser * Yasushi SHOJI <yashi@atmark-techno.com>
76260fb04SPeter Tyser *
81a459660SWolfgang Denk * SPDX-License-Identifier:	GPL-2.0+
96260fb04SPeter Tyser */
106260fb04SPeter Tyser
1125ddd1fbSWolfgang Denk#include <asm-offsets.h>
126260fb04SPeter Tyser#include <config.h>
136260fb04SPeter Tyser
146260fb04SPeter Tyser	.text
156260fb04SPeter Tyser	.global _start
166260fb04SPeter Tyser_start:
1786c1b2a8SMichal Simek	/*
1886c1b2a8SMichal Simek	 * reserve registers:
1986c1b2a8SMichal Simek	 * r10: Stores little/big endian offset for vectors
2086c1b2a8SMichal Simek	 * r2: Stores imm opcode
2186c1b2a8SMichal Simek	 * r3: Stores brai opcode
2286c1b2a8SMichal Simek	 */
2386c1b2a8SMichal Simek
246260fb04SPeter Tyser	mts	rmsr, r0	/* disable cache */
259d242745SMichal Simek
26da931af1SMichal Simek	addi	r8, r0, __end
27da931af1SMichal Simek	mts	rslr, r8
28ecc30663SAlbert ARIBAUD	/* TODO: Redo this code to call board_init_f_*() */
299d242745SMichal Simek#if defined(CONFIG_SPL_BUILD)
309d242745SMichal Simek	addi	r1, r0, CONFIG_SPL_STACK_ADDR
31da931af1SMichal Simek	mts	rshr, r1
329d242745SMichal Simek	addi	r1, r1, -4	/* Decrement SP to top of memory */
339d242745SMichal Simek#else
34*9eea5016SAndy Yan#if CONFIG_VAL(SYS_MALLOC_F_LEN)
35*9eea5016SAndy Yan	addi	r1, r0, CONFIG_SYS_INIT_SP_OFFSET - CONFIG_VAL(SYS_MALLOC_F_LEN)
36405e651dSMichal Simek#else
376260fb04SPeter Tyser	addi	r1, r0, CONFIG_SYS_INIT_SP_OFFSET
38405e651dSMichal Simek#endif
39da931af1SMichal Simek	mts	rshr, r1
406260fb04SPeter Tyser	addi	r1, r1, -4	/* Decrement SP to top of memory */
41b98cba09SMichal Simek
42b98cba09SMichal Simek	/* Find-out if u-boot is running on BIG/LITTLE endian platform
43b98cba09SMichal Simek	 * There are some steps which is necessary to keep in mind:
44b98cba09SMichal Simek	 * 1. Setup offset value to r6
45b98cba09SMichal Simek	 * 2. Store word offset value to address 0x0
46b98cba09SMichal Simek	 * 3. Load just byte from address 0x0
47b98cba09SMichal Simek	 * 4a) LITTLE endian - r10 contains 0x2 because it is the smallest
48b98cba09SMichal Simek	 *     value that's why is on address 0x0
49b98cba09SMichal Simek	 * 4b) BIG endian - r10 contains 0x0 because 0x2 offset is on addr 0x3
50b98cba09SMichal Simek	 */
51b98cba09SMichal Simek	addik	r6, r0, 0x2 /* BIG/LITTLE endian offset */
52f3090fceSMichal Simek	lwi	r7, r0, 0x28
53f3090fceSMichal Simek	swi	r6, r0, 0x28 /* used first unused MB vector */
54f3090fceSMichal Simek	lbui	r10, r0, 0x28 /* used first unused MB vector */
55f3090fceSMichal Simek	swi	r7, r0, 0x28
56b98cba09SMichal Simek
576260fb04SPeter Tyser	/* add opcode instruction for 32bit jump - 2 instruction imm & brai */
5886c1b2a8SMichal Simek	addi	r2, r0, 0xb0000000	/* hex b000 opcode imm */
5986c1b2a8SMichal Simek	addi	r3, r0, 0xb8080000	/* hew b808 opcode brai */
606260fb04SPeter Tyser
616260fb04SPeter Tyser#ifdef CONFIG_SYS_RESET_ADDRESS
626260fb04SPeter Tyser	/* reset address */
6386c1b2a8SMichal Simek	swi	r2, r0, 0x0	/* reset address - imm opcode */
6486c1b2a8SMichal Simek	swi	r3, r0, 0x4	/* reset address - brai opcode */
6586c1b2a8SMichal Simek
666260fb04SPeter Tyser	addik	r6, r0, CONFIG_SYS_RESET_ADDRESS
676260fb04SPeter Tyser	sw	r6, r1, r0
685562bcc2SMichal Simek	lhu	r7, r1, r10
695562bcc2SMichal Simek	rsubi	r8, r10, 0x2
705562bcc2SMichal Simek	sh	r7, r0, r8
715562bcc2SMichal Simek	rsubi	r8, r10, 0x6
725562bcc2SMichal Simek	sh	r6, r0, r8
736260fb04SPeter Tyser#endif
746260fb04SPeter Tyser
756260fb04SPeter Tyser#ifdef CONFIG_SYS_USR_EXCEP
766260fb04SPeter Tyser	/* user_vector_exception */
7786c1b2a8SMichal Simek	swi	r2, r0, 0x8	/* user vector exception - imm opcode */
7886c1b2a8SMichal Simek	swi	r3, r0, 0xC	/* user vector exception - brai opcode */
7986c1b2a8SMichal Simek
806260fb04SPeter Tyser	addik	r6, r0, _exception_handler
816260fb04SPeter Tyser	sw	r6, r1, r0
82b98cba09SMichal Simek	/*
83b98cba09SMichal Simek	 * BIG ENDIAN memory map for user exception
84b98cba09SMichal Simek	 * 0x8: 0xB000XXXX
85b98cba09SMichal Simek	 * 0xC: 0xB808XXXX
86b98cba09SMichal Simek	 *
87b98cba09SMichal Simek	 * then it is necessary to count address for storing the most significant
88b98cba09SMichal Simek	 * 16bits from _exception_handler address and copy it to
89b98cba09SMichal Simek	 * 0xa address. Big endian use offset in r10=0 that's why is it just
90b98cba09SMichal Simek	 * 0xa address. The same is done for the least significant 16 bits
91b98cba09SMichal Simek	 * for 0xe address.
92b98cba09SMichal Simek	 *
93b98cba09SMichal Simek	 * LITTLE ENDIAN memory map for user exception
94b98cba09SMichal Simek	 * 0x8: 0xXXXX00B0
95b98cba09SMichal Simek	 * 0xC: 0xXXXX08B8
96b98cba09SMichal Simek	 *
97b98cba09SMichal Simek	 * Offset is for little endian setup to 0x2. rsubi instruction decrease
98b98cba09SMichal Simek	 * address value to ensure that points to proper place which is
99b98cba09SMichal Simek	 * 0x8 for the most significant 16 bits and
100b98cba09SMichal Simek	 * 0xC for the least significant 16 bits
101b98cba09SMichal Simek	 */
102b98cba09SMichal Simek	lhu	r7, r1, r10
103b98cba09SMichal Simek	rsubi	r8, r10, 0xa
104b98cba09SMichal Simek	sh	r7, r0, r8
105b98cba09SMichal Simek	rsubi	r8, r10, 0xe
106b98cba09SMichal Simek	sh	r6, r0, r8
1076260fb04SPeter Tyser#endif
1086260fb04SPeter Tyser
1096260fb04SPeter Tyser	/* interrupt_handler */
11086c1b2a8SMichal Simek	swi	r2, r0, 0x10	/* interrupt - imm opcode */
11186c1b2a8SMichal Simek	swi	r3, r0, 0x14	/* interrupt - brai opcode */
11286c1b2a8SMichal Simek
1136260fb04SPeter Tyser	addik	r6, r0, _interrupt_handler
1146260fb04SPeter Tyser	sw	r6, r1, r0
115b98cba09SMichal Simek	lhu	r7, r1, r10
116b98cba09SMichal Simek	rsubi	r8, r10, 0x12
117b98cba09SMichal Simek	sh	r7, r0, r8
118b98cba09SMichal Simek	rsubi	r8, r10, 0x16
119b98cba09SMichal Simek	sh	r6, r0, r8
1206260fb04SPeter Tyser
1216260fb04SPeter Tyser	/* hardware exception */
12286c1b2a8SMichal Simek	swi	r2, r0, 0x20	/* hardware exception - imm opcode */
12386c1b2a8SMichal Simek	swi	r3, r0, 0x24	/* hardware exception - brai opcode */
12486c1b2a8SMichal Simek
1256260fb04SPeter Tyser	addik	r6, r0, _hw_exception_handler
1266260fb04SPeter Tyser	sw	r6, r1, r0
127b98cba09SMichal Simek	lhu	r7, r1, r10
128b98cba09SMichal Simek	rsubi	r8, r10, 0x22
129b98cba09SMichal Simek	sh	r7, r0, r8
130b98cba09SMichal Simek	rsubi	r8, r10, 0x26
131b98cba09SMichal Simek	sh	r6, r0, r8
1321d82e2c1SMichal Simek#endif /* CONFIG_SPL_BUILD */
1336260fb04SPeter Tyser
1345811830fSMichal Simek	/* Flush cache before enable cache */
1355811830fSMichal Simek	addik	r5, r0, 0
1365811830fSMichal Simek	addik	r6, r0, XILINX_DCACHE_BYTE_SIZE
137e4a4743eSMichal Simek	bralid r15, flush_cache
1385811830fSMichal Simek	nop
1395811830fSMichal Simek
1406260fb04SPeter Tyser	/* enable instruction and data cache */
1416260fb04SPeter Tyser	mfs	r12, rmsr
142822d43a6SMichal Simek	ori	r12, r12, 0x1a0
1436260fb04SPeter Tyser	mts	rmsr, r12
1446260fb04SPeter Tyser
145ecc30663SAlbert ARIBAUD	/* TODO: Redo this code to call board_init_f_*() */
1466260fb04SPeter Tyserclear_bss:
1476260fb04SPeter Tyser	/* clear BSS segments */
1486260fb04SPeter Tyser	addi	r5, r0, __bss_start
1496260fb04SPeter Tyser	addi	r4, r0, __bss_end
1506260fb04SPeter Tyser	cmp	r6, r5, r4
1516260fb04SPeter Tyser	beqi	r6, 3f
1526260fb04SPeter Tyser2:
1536260fb04SPeter Tyser	swi     r0, r5, 0 /* write zero to loc */
1546260fb04SPeter Tyser	addi    r5, r5, 4 /* increment to next loc */
1556260fb04SPeter Tyser	cmp     r6, r5, r4 /* check if we have reach the end */
1566260fb04SPeter Tyser	bnei    r6, 2b
1576260fb04SPeter Tyser3:	/* jumping to board_init */
15848470b7aSMichal Simek#ifdef CONFIG_DEBUG_UART
15948470b7aSMichal Simek	bralid	r15, debug_uart_init
16048470b7aSMichal Simek	nop
16148470b7aSMichal Simek#endif
1629d242745SMichal Simek#ifndef CONFIG_SPL_BUILD
163e945f6dcSMichal Simek	or	r5, r0, r0	/* flags - empty */
1640510b14bSMichal Simek	addi    r31, r0, _gd
165*9eea5016SAndy Yan#if CONFIG_VAL(SYS_MALLOC_F_LEN)
166405e651dSMichal Simek	addi	r6, r0, CONFIG_SYS_INIT_SP_OFFSET
167405e651dSMichal Simek	swi	r6, r31, GD_MALLOC_BASE
168405e651dSMichal Simek#endif
1692380b8f5SMichal Simek	brai	board_init_f
1709d242745SMichal Simek#else
171ca7d2266SMichal Simek	addi	r31, r0, _gd
172*9eea5016SAndy Yan#if CONFIG_VAL(SYS_MALLOC_F_LEN)
173ca7d2266SMichal Simek	addi	r6, r0, CONFIG_SPL_STACK_ADDR
174ca7d2266SMichal Simek	swi	r6, r31, GD_MALLOC_BASE
175ca7d2266SMichal Simek#endif
1769d242745SMichal Simek	brai	board_init_r
1779d242745SMichal Simek#endif
1786260fb04SPeter Tyser1:	bri	1b
1796260fb04SPeter Tyser
1800510b14bSMichal Simek .section .bss
1810510b14bSMichal Simek.align 4
1820510b14bSMichal Simek_gd:
1830510b14bSMichal Simek         .space  GENERATED_GBL_DATA_SIZE
1840510b14bSMichal Simek
1859d242745SMichal Simek#ifndef CONFIG_SPL_BUILD
1866260fb04SPeter Tyser/*
1876260fb04SPeter Tyser * Read 16bit little endian
1886260fb04SPeter Tyser */
1896260fb04SPeter Tyser	.text
1906260fb04SPeter Tyser	.global	in16
1916260fb04SPeter Tyser	.ent	in16
1926260fb04SPeter Tyser	.align	2
1936260fb04SPeter Tyserin16:	lhu	r3, r0, r5
1946260fb04SPeter Tyser	bslli	r4, r3, 8
1956260fb04SPeter Tyser	bsrli	r3, r3, 8
1966260fb04SPeter Tyser	andi	r4, r4, 0xffff
1976260fb04SPeter Tyser	or	r3, r3, r4
1986260fb04SPeter Tyser	rtsd	r15, 8
1996260fb04SPeter Tyser	sext16	r3, r3
2006260fb04SPeter Tyser	.end	in16
2016260fb04SPeter Tyser
2026260fb04SPeter Tyser/*
2036260fb04SPeter Tyser * Write 16bit little endian
2046260fb04SPeter Tyser * first parameter(r5) - address, second(r6) - short value
2056260fb04SPeter Tyser */
2066260fb04SPeter Tyser	.text
2076260fb04SPeter Tyser	.global	out16
2086260fb04SPeter Tyser	.ent	out16
2096260fb04SPeter Tyser	.align	2
2106260fb04SPeter Tyserout16:	bslli	r3, r6, 8
2116260fb04SPeter Tyser	bsrli	r6, r6, 8
2126260fb04SPeter Tyser	andi	r3, r3, 0xffff
2136260fb04SPeter Tyser	or	r3, r3, r6
2146260fb04SPeter Tyser	sh	r3, r0, r5
2156260fb04SPeter Tyser	rtsd	r15, 8
2166260fb04SPeter Tyser	or	r0, r0, r0
2176260fb04SPeter Tyser	.end	out16
218e945f6dcSMichal Simek
219e945f6dcSMichal Simek/*
220e945f6dcSMichal Simek * Relocate u-boot
221e945f6dcSMichal Simek */
222e945f6dcSMichal Simek	.text
223e945f6dcSMichal Simek	.global	relocate_code
224e945f6dcSMichal Simek	.ent	relocate_code
225e945f6dcSMichal Simek	.align	2
226e945f6dcSMichal Simekrelocate_code:
227e945f6dcSMichal Simek	/*
228e945f6dcSMichal Simek	 * r5 - start_addr_sp
229e945f6dcSMichal Simek	 * r6 - new_gd
230e945f6dcSMichal Simek	 * r7 - reloc_addr
231e945f6dcSMichal Simek	 */
232e945f6dcSMichal Simek	addi	r1, r5, 0 /* Start to use new SP */
233e945f6dcSMichal Simek	addi	r31, r6, 0 /* Start to use new GD */
234e945f6dcSMichal Simek
235e945f6dcSMichal Simek	add	r23, r0, r7 /* Move reloc addr to r23 */
236e945f6dcSMichal Simek	/* Relocate text and data - r12 temp value */
237e945f6dcSMichal Simek	addi	r21, r0, _start
238e945f6dcSMichal Simek	addi	r22, r0, __end - 4 /* Include BSS too */
2397c4dd542SMichal Simek
2407c4dd542SMichal Simek	rsub	r6, r21, r22
2417c4dd542SMichal Simek	or	r5, r0, r0
2427c4dd542SMichal Simek1:	lw	r12, r21, r5 /* Load u-boot data */
2437c4dd542SMichal Simek	sw	r12, r23, r5 /* Write zero to loc */
2447c4dd542SMichal Simek	cmp	r12, r5, r6 /* Check if we have reach the end */
245e945f6dcSMichal Simek	bneid	r12, 1b
2467c4dd542SMichal Simek	addi	r5, r5, 4 /* Increment to next loc - relocate code */
247e945f6dcSMichal Simek
248e945f6dcSMichal Simek       /* R23 points to the base address. */
249e945f6dcSMichal Simek	add	r23, r0, r7 /* Move reloc addr to r23 */
250e945f6dcSMichal Simek	addi	r24, r0, CONFIG_SYS_TEXT_BASE /* Get reloc offset */
251e945f6dcSMichal Simek	rsub	r23, r24, r23 /* keep - this is already here gd->reloc_off */
252e945f6dcSMichal Simek
253e945f6dcSMichal Simek	addik	r6, r0, 0x2 /* BIG/LITTLE endian offset */
254e945f6dcSMichal Simek	lwi	r7, r0, 0x28
255e945f6dcSMichal Simek	swi	r6, r0, 0x28 /* used first unused MB vector */
256e945f6dcSMichal Simek	lbui	r10, r0, 0x28 /* used first unused MB vector */
257e945f6dcSMichal Simek	swi	r7, r0, 0x28
258e945f6dcSMichal Simek
259e945f6dcSMichal Simek#ifdef CONFIG_SYS_USR_EXCEP
260e945f6dcSMichal Simek	addik	r6, r0, _exception_handler
261e945f6dcSMichal Simek	addk	r6, r6, r23 /* add offset */
262e945f6dcSMichal Simek	sw	r6, r1, r0
263e945f6dcSMichal Simek	lhu	r7, r1, r10
264e945f6dcSMichal Simek	rsubi	r8, r10, 0xa
265e945f6dcSMichal Simek	sh	r7, r0, r8
266e945f6dcSMichal Simek	rsubi	r8, r10, 0xe
267e945f6dcSMichal Simek	sh	r6, r0, r8
268e945f6dcSMichal Simek#endif
269e945f6dcSMichal Simek	addik	r6, r0, _hw_exception_handler
270e945f6dcSMichal Simek	addk	r6, r6, r23 /* add offset */
271e945f6dcSMichal Simek	sw	r6, r1, r0
272e945f6dcSMichal Simek	lhu	r7, r1, r10
273e945f6dcSMichal Simek	rsubi	r8, r10, 0x22
274e945f6dcSMichal Simek	sh	r7, r0, r8
275e945f6dcSMichal Simek	rsubi	r8, r10, 0x26
276e945f6dcSMichal Simek	sh	r6, r0, r8
277e945f6dcSMichal Simek
278e945f6dcSMichal Simek	addik	r6, r0, _interrupt_handler
279e945f6dcSMichal Simek	addk	r6, r6, r23 /* add offset */
280e945f6dcSMichal Simek	sw	r6, r1, r0
281e945f6dcSMichal Simek	lhu	r7, r1, r10
282e945f6dcSMichal Simek	rsubi	r8, r10, 0x12
283e945f6dcSMichal Simek	sh	r7, r0, r8
284e945f6dcSMichal Simek	rsubi	r8, r10, 0x16
285e945f6dcSMichal Simek	sh	r6, r0, r8
286e945f6dcSMichal Simek
287e945f6dcSMichal Simek	/* Check if GOT exist */
288e945f6dcSMichal Simek	addik	r21, r23, _got_start
289e945f6dcSMichal Simek	addik	r22, r23, _got_end
290e945f6dcSMichal Simek	cmpu	r12, r21, r22
291e945f6dcSMichal Simek	beqi	r12, 2f /* No GOT table - jump over */
292e945f6dcSMichal Simek
293e945f6dcSMichal Simek	/* Skip last 3 entries plus 1 because of loop boundary below */
294e945f6dcSMichal Simek	addik	r22, r22, -0x10
295e945f6dcSMichal Simek
296e945f6dcSMichal Simek        /* Relocate the GOT. */
297e945f6dcSMichal Simek3:	lw	r12, r21, r0 /* Load entry */
298e945f6dcSMichal Simek	addk	r12, r12, r23 /* Add reloc offset */
299e945f6dcSMichal Simek	sw	r12, r21, r0 /* Save entry back */
300e945f6dcSMichal Simek
301e945f6dcSMichal Simek	cmpu	r12, r21, r22 /* Check if this cross boundary */
302e945f6dcSMichal Simek	bneid	r12, 3b
303e945f6dcSMichal Simek	addik	r21. r21, 4
304e945f6dcSMichal Simek
305e945f6dcSMichal Simek	/* Update pointer to GOT */
306e945f6dcSMichal Simek	mfs	r20, rpc
307e945f6dcSMichal Simek	addik	r20, r20, _GLOBAL_OFFSET_TABLE_ + 8
308e945f6dcSMichal Simek	addk	r20, r20, r23
309e945f6dcSMichal Simek
310e945f6dcSMichal Simek	/* Flush caches to ensure consistency */
311e945f6dcSMichal Simek	addik	r5, r0, 0
312e945f6dcSMichal Simek	addik	r6, r0, XILINX_DCACHE_BYTE_SIZE
313e945f6dcSMichal Simek	bralid	r15, flush_cache
314e945f6dcSMichal Simek	nop
315e945f6dcSMichal Simek
316e945f6dcSMichal Simek2:	addi	r5, r31, 0 /* gd is initialized in board_r.c */
317e945f6dcSMichal Simek	addi	r6, r0, CONFIG_SYS_TEXT_BASE
318e945f6dcSMichal Simek	addi	r12, r23, board_init_r
319e945f6dcSMichal Simek	bra	r12 /* Jump to relocated code */
320e945f6dcSMichal Simek
321e945f6dcSMichal Simek	.end	relocate_code
3229d242745SMichal Simek#endif
323