| /* SPDX-License-Identifier: GPL-2.0+ */ |
| /* |
| * (C) Copyright 2007 Michal Simek |
| * (C) Copyright 2004 Atmark Techno, Inc. |
| * |
| * Michal SIMEK <monstr@monstr.eu> |
| * Yasushi SHOJI <yashi@atmark-techno.com> |
| */ |
| |
| #include <asm-offsets.h> |
| #include <config.h> |
| |
| .text |
| .global _start |
| _start: |
| mts rmsr, r0 /* disable cache */ |
| |
| mts rslr, r0 |
| addi r8, r0, _start |
| mts rshr, r8 |
| |
| #if defined(CONFIG_SPL_BUILD) |
| addi r1, r0, CONFIG_SPL_STACK_ADDR |
| #else |
| add r1, r0, r8 |
| #endif |
| |
| addi r1, r1, -4 /* Decrement SP to top of memory */ |
| |
| /* Call board_init_f_alloc_reserve with the current stack pointer as |
| * parameter. */ |
| add r5, r0, r1 |
| brlid r15, board_init_f_alloc_reserve |
| nop |
| |
| /* board_init_f_alloc_reserve returns a pointer to the allocated area |
| * in r3. Set the new stack pointer below this area. */ |
| add r1, r0, r3 |
| mts rshr, r1 |
| addi r1, r1, -4 |
| |
| /* Call board_init_f_init_reserve with the address returned by |
| * board_init_f_alloc_reserve as parameter. */ |
| add r5, r0, r3 |
| brlid r15, board_init_f_init_reserve |
| nop |
| |
| #if !defined(CONFIG_SPL_BUILD) |
| /* Setup vectors with pre-relocation symbols */ |
| or r5, r0, r0 |
| brlid r15, __setup_exceptions |
| nop |
| #endif |
| |
| /* Flush cache before enable cache */ |
| addik r5, r0, 0 |
| addik r6, r0, XILINX_DCACHE_BYTE_SIZE |
| brlid r15, flush_cache |
| nop |
| |
| /* enable instruction and data cache */ |
| mfs r12, rmsr |
| ori r12, r12, 0x1a0 |
| mts rmsr, r12 |
| |
| clear_bss: |
| /* clear BSS segments */ |
| addi r5, r0, __bss_start |
| addi r4, r0, __bss_end |
| cmp r6, r5, r4 |
| beqi r6, 3f |
| 2: |
| swi r0, r5, 0 /* write zero to loc */ |
| addi r5, r5, 4 /* increment to next loc */ |
| cmp r6, r5, r4 /* check if we have reach the end */ |
| bnei r6, 2b |
| 3: /* jumping to board_init */ |
| #ifdef CONFIG_DEBUG_UART |
| brlid r15, debug_uart_init |
| nop |
| #endif |
| #ifndef CONFIG_SPL_BUILD |
| or r5, r0, r0 /* flags - empty */ |
| bri board_init_f |
| #else |
| bri board_init_r |
| #endif |
| 1: bri 1b |
| |
| #ifndef CONFIG_SPL_BUILD |
| .text |
| .ent __setup_exceptions |
| .align 2 |
| /* |
| * Set up reset, interrupt, user exception and hardware exception vectors. |
| * |
| * Parameters: |
| * r5 - relocation offset (zero when setting up vectors before |
| * relocation, and gd->reloc_off when setting up vectors after |
| * relocation) |
| * - the relocation offset is added to the _exception_handler, |
| * _interrupt_handler and _hw_exception_handler symbols to reflect the |
| * post-relocation memory addresses |
| * |
| * Reserve registers: |
| * r10: Stores little/big endian offset for vectors |
| * r2: Stores imm opcode |
| * r3: Stores brai opcode |
| * r4: Stores the vector base address |
| */ |
| __setup_exceptions: |
| addik r1, r1, -32 |
| swi r2, r1, 4 |
| swi r3, r1, 8 |
| swi r4, r1, 12 |
| swi r6, r1, 16 |
| swi r7, r1, 20 |
| swi r8, r1, 24 |
| swi r10, r1, 28 |
| |
| /* Find-out if u-boot is running on BIG/LITTLE endian platform |
| * There are some steps which is necessary to keep in mind: |
| * 1. Setup offset value to r6 |
| * 2. Store word offset value to address 0x0 |
| * 3. Load just byte from address 0x0 |
| * 4a) LITTLE endian - r10 contains 0x2 because it is the smallest |
| * value that's why is on address 0x0 |
| * 4b) BIG endian - r10 contains 0x0 because 0x2 offset is on addr 0x3 |
| */ |
| addik r6, r0, 0x2 /* BIG/LITTLE endian offset */ |
| sw r6, r1, r0 |
| lbu r10, r1, r0 |
| |
| /* add opcode instruction for 32bit jump - 2 instruction imm & brai */ |
| addi r2, r0, 0xb0000000 /* hex b000 opcode imm */ |
| addi r3, r0, 0xb8080000 /* hew b808 opcode brai */ |
| |
| /* Store the vector base address in r4 */ |
| addi r4, r0, CONFIG_XILINX_MICROBLAZE0_VECTOR_BASE_ADDR |
| |
| /* reset address */ |
| swi r2, r4, 0x0 /* reset address - imm opcode */ |
| swi r3, r4, 0x4 /* reset address - brai opcode */ |
| |
| addik r6, r0, _start |
| sw r6, r1, r0 |
| lhu r7, r1, r10 |
| rsubi r8, r10, 0x2 |
| sh r7, r4, r8 |
| rsubi r8, r10, 0x6 |
| sh r6, r4, r8 |
| |
| #if CONFIG_IS_ENABLED(XILINX_MICROBLAZE0_USR_EXCEP) |
| /* user_vector_exception */ |
| swi r2, r4, 0x8 /* user vector exception - imm opcode */ |
| swi r3, r4, 0xC /* user vector exception - brai opcode */ |
| |
| addik r6, r5, _exception_handler |
| sw r6, r1, r0 |
| /* |
| * BIG ENDIAN memory map for user exception |
| * 0x8: 0xB000XXXX |
| * 0xC: 0xB808XXXX |
| * |
| * then it is necessary to count address for storing the most significant |
| * 16bits from _exception_handler address and copy it to |
| * 0xa address. Big endian use offset in r10=0 that's why is it just |
| * 0xa address. The same is done for the least significant 16 bits |
| * for 0xe address. |
| * |
| * LITTLE ENDIAN memory map for user exception |
| * 0x8: 0xXXXX00B0 |
| * 0xC: 0xXXXX08B8 |
| * |
| * Offset is for little endian setup to 0x2. rsubi instruction decrease |
| * address value to ensure that points to proper place which is |
| * 0x8 for the most significant 16 bits and |
| * 0xC for the least significant 16 bits |
| */ |
| lhu r7, r1, r10 |
| rsubi r8, r10, 0xa |
| sh r7, r4, r8 |
| rsubi r8, r10, 0xe |
| sh r6, r4, r8 |
| #endif |
| |
| /* interrupt_handler */ |
| swi r2, r4, 0x10 /* interrupt - imm opcode */ |
| swi r3, r4, 0x14 /* interrupt - brai opcode */ |
| |
| addik r6, r5, _interrupt_handler |
| sw r6, r1, r0 |
| lhu r7, r1, r10 |
| rsubi r8, r10, 0x12 |
| sh r7, r4, r8 |
| rsubi r8, r10, 0x16 |
| sh r6, r4, r8 |
| |
| /* hardware exception */ |
| swi r2, r4, 0x20 /* hardware exception - imm opcode */ |
| swi r3, r4, 0x24 /* hardware exception - brai opcode */ |
| |
| addik r6, r5, _hw_exception_handler |
| sw r6, r1, r0 |
| lhu r7, r1, r10 |
| rsubi r8, r10, 0x22 |
| sh r7, r4, r8 |
| rsubi r8, r10, 0x26 |
| sh r6, r4, r8 |
| |
| lwi r10, r1, 28 |
| lwi r8, r1, 24 |
| lwi r7, r1, 20 |
| lwi r6, r1, 16 |
| lwi r4, r1, 12 |
| lwi r3, r1, 8 |
| lwi r2, r1, 4 |
| addik r1, r1, 32 |
| |
| rtsd r15, 8 |
| or r0, r0, r0 |
| .end __setup_exceptions |
| |
| /* |
| * Read 16bit little endian |
| */ |
| .text |
| .global in16 |
| .ent in16 |
| .align 2 |
| in16: lhu r3, r0, r5 |
| bslli r4, r3, 8 |
| bsrli r3, r3, 8 |
| andi r4, r4, 0xffff |
| or r3, r3, r4 |
| rtsd r15, 8 |
| sext16 r3, r3 |
| .end in16 |
| |
| /* |
| * Write 16bit little endian |
| * first parameter(r5) - address, second(r6) - short value |
| */ |
| .text |
| .global out16 |
| .ent out16 |
| .align 2 |
| out16: bslli r3, r6, 8 |
| bsrli r6, r6, 8 |
| andi r3, r3, 0xffff |
| or r3, r3, r6 |
| sh r3, r0, r5 |
| rtsd r15, 8 |
| or r0, r0, r0 |
| .end out16 |
| |
| /* |
| * Relocate u-boot |
| */ |
| .text |
| .global relocate_code |
| .ent relocate_code |
| .align 2 |
| relocate_code: |
| /* |
| * r5 - start_addr_sp |
| * r6 - new_gd |
| * r7 - reloc_addr |
| */ |
| addi r1, r5, 0 /* Start to use new SP */ |
| mts rshr, r1 |
| addi r31, r6, 0 /* Start to use new GD */ |
| |
| add r23, r0, r7 /* Move reloc addr to r23 */ |
| /* Relocate text and data - r12 temp value */ |
| addi r21, r0, _start |
| addi r22, r0, _end /* Include BSS too */ |
| addi r22, r22, -4 |
| |
| rsub r6, r21, r22 |
| or r5, r0, r0 |
| 1: lw r12, r21, r5 /* Load u-boot data */ |
| sw r12, r23, r5 /* Write zero to loc */ |
| cmp r12, r5, r6 /* Check if we have reach the end */ |
| bneid r12, 1b |
| addi r5, r5, 4 /* Increment to next loc - relocate code */ |
| |
| /* R23 points to the base address. */ |
| add r23, r0, r7 /* Move reloc addr to r23 */ |
| addi r24, r0, _start /* Get reloc offset */ |
| rsub r23, r24, r23 /* keep - this is already here gd->reloc_off */ |
| |
| /* Setup vectors with post-relocation symbols */ |
| add r5, r0, r23 /* load gd->reloc_off to r5 */ |
| brlid r15, __setup_exceptions |
| nop |
| |
| /* Check if GOT exist */ |
| addik r21, r23, _got_start |
| addik r22, r23, _got_end |
| cmpu r12, r21, r22 |
| beqi r12, 2f /* No GOT table - jump over */ |
| |
| /* Skip last 3 entries plus 1 because of loop boundary below */ |
| addik r22, r22, -0x10 |
| |
| /* Relocate the GOT. */ |
| 3: lw r12, r21, r0 /* Load entry */ |
| addk r12, r12, r23 /* Add reloc offset */ |
| sw r12, r21, r0 /* Save entry back */ |
| |
| cmpu r12, r21, r22 /* Check if this cross boundary */ |
| bneid r12, 3b |
| addik r21. r21, 4 |
| |
| /* Update pointer to GOT */ |
| mfs r20, rpc |
| addik r20, r20, _GLOBAL_OFFSET_TABLE_ + 8 |
| addk r20, r20, r23 |
| |
| /* Flush caches to ensure consistency */ |
| addik r5, r0, 0 |
| addik r6, r0, XILINX_DCACHE_BYTE_SIZE |
| brlid r15, flush_cache |
| nop |
| |
| 2: addi r5, r31, 0 /* gd is initialized in board_r.c */ |
| addi r6, r0, _start |
| addi r12, r23, board_init_r |
| bra r12 /* Jump to relocated code */ |
| |
| .end relocate_code |
| #endif |