microblaze/cpu/start.S

1 /* SPDX-License-Identifier: GPL-2.0+ */
7  * Yasushi SHOJI <yashi@atmark-techno.com>
10 #include <asm-offsets.h>
18 	 * r10: Stores little/big endian offset for vectors
31 	addi	r1, r1, -4	/* Decrement SP to top of memory */
34 	addi	r1, r0, CONFIG_SYS_INIT_SP_OFFSET - CONFIG_VAL(SYS_MALLOC_F_LEN)
39 	addi	r1, r1, -4	/* Decrement SP to top of memory */
41 	/* Find-out if u-boot is running on BIG/LITTLE endian platform
46 	 * 4a) LITTLE endian - r10 contains 0x2 because it is the smallest
48 	 * 4b) BIG endian - r10 contains 0x0 because 0x2 offset is on addr 0x3
50 	addik	r6, r0, 0x2 /* BIG/LITTLE endian offset */
56 	/* add opcode instruction for 32bit jump - 2 instruction imm & brai */
62 	swi	r2, r0, 0x0	/* reset address - imm opcode */
63 	swi	r3, r0, 0x4	/* reset address - brai opcode */
76 	swi	r2, r0, 0x8	/* user vector exception - imm opcode */
77 	swi	r3, r0, 0xC	/* user vector exception - brai opcode */
82 	 * BIG ENDIAN memory map for user exception
88 	 * 0xa address. Big endian use offset in r10=0 that's why is it just
92 	 * LITTLE ENDIAN memory map for user exception
96 	 * Offset is for little endian setup to 0x2. rsubi instruction decrease
109 	swi	r2, r0, 0x10	/* interrupt - imm opcode */
110 	swi	r3, r0, 0x14	/* interrupt - brai opcode */
121 	swi	r2, r0, 0x20	/* hardware exception - imm opcode */
122 	swi	r3, r0, 0x24	/* hardware exception - brai opcode */
162 	or	r5, r0, r0	/* flags - empty */
186  * Read 16bit little endian
202  * Write 16bit little endian
203  * first parameter(r5) - address, second(r6) - short value
219  * Relocate u-boot
227 	 * r5 - start_addr_sp
228 	 * r6 - new_gd
229 	 * r7 - reloc_addr
235 	/* Relocate text and data - r12 temp value */
237 	addi	r22, r0, __end - 4 /* Include BSS too */
241 1:	lw	r12, r21, r5 /* Load u-boot data */
245 	addi	r5, r5, 4 /* Increment to next loc - relocate code */
250 	rsub	r23, r24, r23 /* keep - this is already here gd->reloc_off */
252 	addik	r6, r0, 0x2 /* BIG/LITTLE endian offset */
290 	beqi	r12, 2f /* No GOT table - jump over */
293 	addik	r22, r22, -0x10