| /* |
| * Startup Code for MIPS32 CPU-core |
| * |
| * Copyright (c) 2003 Wolfgang Denk <wd@denx.de> |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| */ |
| |
| #include <asm-offsets.h> |
| #include <config.h> |
| #include <asm/asm.h> |
| #include <asm/regdef.h> |
| #include <asm/mipsregs.h> |
| |
| #ifndef CONFIG_SYS_INIT_SP_ADDR |
| #define CONFIG_SYS_INIT_SP_ADDR (CONFIG_SYS_SDRAM_BASE + \ |
| CONFIG_SYS_INIT_SP_OFFSET) |
| #endif |
| |
| #ifdef CONFIG_32BIT |
| # define MIPS_RELOC 3 |
| # define STATUS_SET 0 |
| #endif |
| |
| #ifdef CONFIG_64BIT |
| # ifdef CONFIG_SYS_LITTLE_ENDIAN |
| # define MIPS64_R_INFO(ssym, r_type3, r_type2, r_type) \ |
| (((r_type) << 24) | ((r_type2) << 16) | ((r_type3) << 8) | (ssym)) |
| # else |
| # define MIPS64_R_INFO(ssym, r_type3, r_type2, r_type) \ |
| ((r_type) | ((r_type2) << 8) | ((r_type3) << 16) | (ssym) << 24) |
| # endif |
| # define MIPS_RELOC MIPS64_R_INFO(0x00, 0x00, 0x12, 0x03) |
| # define STATUS_SET ST0_KX |
| #endif |
| |
| /* |
| * For the moment disable interrupts, mark the kernel mode and |
| * set ST0_KX so that the CPU does not spit fire when using |
| * 64-bit addresses. |
| */ |
| .macro setup_c0_status set clr |
| .set push |
| mfc0 t0, CP0_STATUS |
| or t0, ST0_CU0 | \set | 0x1f | \clr |
| xor t0, 0x1f | \clr |
| mtc0 t0, CP0_STATUS |
| .set noreorder |
| sll zero, 3 # ehb |
| .set pop |
| .endm |
| |
| .set noreorder |
| |
| ENTRY(_start) |
| /* U-Boot entry point */ |
| b reset |
| nop |
| |
| .org 0x10 |
| #if defined(CONFIG_SYS_XWAY_EBU_BOOTCFG) |
| /* |
| * Almost all Lantiq XWAY SoC devices have an external bus unit (EBU) to |
| * access external NOR flashes. If the board boots from NOR flash the |
| * internal BootROM does a blind read at address 0xB0000010 to read the |
| * initial configuration for that EBU in order to access the flash |
| * device with correct parameters. This config option is board-specific. |
| */ |
| .word CONFIG_SYS_XWAY_EBU_BOOTCFG |
| .word 0x0 |
| #elif defined(CONFIG_MALTA) |
| /* |
| * Linux expects the Board ID here. |
| */ |
| .word 0x00000420 # 0x420 (Malta Board with CoreLV) |
| .word 0x00000000 |
| #endif |
| |
| .org 0x200 |
| /* TLB refill, 32 bit task */ |
| 1: b 1b |
| nop |
| |
| .org 0x280 |
| /* XTLB refill, 64 bit task */ |
| 1: b 1b |
| nop |
| |
| .org 0x300 |
| /* Cache error exception */ |
| 1: b 1b |
| nop |
| |
| .org 0x380 |
| /* General exception */ |
| 1: b 1b |
| nop |
| |
| .org 0x400 |
| /* Catch interrupt exceptions */ |
| 1: b 1b |
| nop |
| |
| .org 0x480 |
| /* EJTAG debug exception */ |
| 1: b 1b |
| nop |
| |
| .align 4 |
| reset: |
| |
| /* Clear watch registers */ |
| MTC0 zero, CP0_WATCHLO |
| mtc0 zero, CP0_WATCHHI |
| |
| /* WP(Watch Pending), SW0/1 should be cleared */ |
| mtc0 zero, CP0_CAUSE |
| |
| setup_c0_status STATUS_SET 0 |
| |
| /* Init Timer */ |
| mtc0 zero, CP0_COUNT |
| mtc0 zero, CP0_COMPARE |
| |
| #ifndef CONFIG_SKIP_LOWLEVEL_INIT |
| mfc0 t0, CP0_CONFIG |
| and t0, t0, MIPS_CONF_IMPL |
| or t0, t0, CONF_CM_UNCACHED |
| mtc0 t0, CP0_CONFIG |
| #endif |
| |
| /* |
| * Initialize $gp, force pointer sized alignment of bal instruction to |
| * forbid the compiler to put nop's between bal and _gp. This is |
| * required to keep _gp and ra aligned to 8 byte. |
| */ |
| .align PTRLOG |
| bal 1f |
| nop |
| PTR _gp |
| 1: |
| PTR_L gp, 0(ra) |
| |
| #ifndef CONFIG_SKIP_LOWLEVEL_INIT |
| # ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD |
| /* Initialize any external memory */ |
| PTR_LA t9, lowlevel_init |
| jalr t9 |
| nop |
| # endif |
| |
| /* Initialize caches... */ |
| PTR_LA t9, mips_cache_reset |
| jalr t9 |
| nop |
| |
| # ifndef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD |
| /* Initialize any external memory */ |
| PTR_LA t9, lowlevel_init |
| jalr t9 |
| nop |
| # endif |
| #endif |
| |
| /* Set up temporary stack */ |
| li t0, -16 |
| PTR_LI t1, CONFIG_SYS_INIT_SP_ADDR |
| and sp, t1, t0 # force 16 byte alignment |
| PTR_SUBU \ |
| sp, sp, GD_SIZE # reserve space for gd |
| and sp, sp, t0 # force 16 byte alignment |
| move k0, sp # save gd pointer |
| #ifdef CONFIG_SYS_MALLOC_F_LEN |
| li t2, CONFIG_SYS_MALLOC_F_LEN |
| PTR_SUBU \ |
| sp, sp, t2 # reserve space for early malloc |
| and sp, sp, t0 # force 16 byte alignment |
| #endif |
| move fp, sp |
| |
| /* Clear gd */ |
| move t0, k0 |
| 1: |
| PTR_S zero, 0(t0) |
| blt t0, t1, 1b |
| PTR_ADDIU t0, PTRSIZE |
| |
| #ifdef CONFIG_SYS_MALLOC_F_LEN |
| PTR_S sp, GD_MALLOC_BASE(k0) # gd->malloc_base offset |
| #endif |
| |
| move a0, zero # a0 <-- boot_flags = 0 |
| PTR_LA t9, board_init_f |
| jr t9 |
| move ra, zero |
| |
| END(_start) |
| |
| /* |
| * void relocate_code (addr_sp, gd, addr_moni) |
| * |
| * This "function" does not return, instead it continues in RAM |
| * after relocating the monitor code. |
| * |
| * a0 = addr_sp |
| * a1 = gd |
| * a2 = destination address |
| */ |
| ENTRY(relocate_code) |
| move sp, a0 # set new stack pointer |
| move fp, sp |
| |
| move s0, a1 # save gd in s0 |
| move s2, a2 # save destination address in s2 |
| |
| PTR_LI t0, CONFIG_SYS_MONITOR_BASE |
| PTR_SUB s1, s2, t0 # s1 <-- relocation offset |
| |
| PTR_LA t3, in_ram |
| PTR_L t2, -(3 * PTRSIZE)(t3) # t2 <-- __image_copy_end |
| move t1, a2 |
| |
| PTR_ADD gp, s1 # adjust gp |
| |
| /* |
| * t0 = source address |
| * t1 = target address |
| * t2 = source end address |
| */ |
| 1: |
| PTR_L t3, 0(t0) |
| PTR_S t3, 0(t1) |
| PTR_ADDU t0, PTRSIZE |
| blt t0, t2, 1b |
| PTR_ADDU t1, PTRSIZE |
| |
| /* If caches were enabled, we would have to flush them here. */ |
| PTR_SUB a1, t1, s2 # a1 <-- size |
| PTR_LA t9, flush_cache |
| jalr t9 |
| move a0, s2 # a0 <-- destination address |
| |
| /* Jump to where we've relocated ourselves */ |
| PTR_ADDIU t0, s2, in_ram - _start |
| jr t0 |
| nop |
| |
| PTR __rel_dyn_end |
| PTR __rel_dyn_start |
| PTR __image_copy_end |
| PTR _GLOBAL_OFFSET_TABLE_ |
| PTR num_got_entries |
| |
| in_ram: |
| /* |
| * Now we want to update GOT. |
| * |
| * GOT[0] is reserved. GOT[1] is also reserved for the dynamic object |
| * generated by GNU ld. Skip these reserved entries from relocation. |
| */ |
| PTR_L t3, -(1 * PTRSIZE)(t0) # t3 <-- num_got_entries |
| PTR_L t8, -(2 * PTRSIZE)(t0) # t8 <-- _GLOBAL_OFFSET_TABLE_ |
| PTR_ADD t8, s1 # t8 now holds relocated _G_O_T_ |
| PTR_ADDIU t8, t8, 2 * PTRSIZE # skipping first two entries |
| PTR_LI t2, 2 |
| 1: |
| PTR_L t1, 0(t8) |
| beqz t1, 2f |
| PTR_ADD t1, s1 |
| PTR_S t1, 0(t8) |
| 2: |
| PTR_ADDIU t2, 1 |
| blt t2, t3, 1b |
| PTR_ADDIU t8, PTRSIZE |
| |
| /* Update dynamic relocations */ |
| PTR_L t1, -(4 * PTRSIZE)(t0) # t1 <-- __rel_dyn_start |
| PTR_L t2, -(5 * PTRSIZE)(t0) # t2 <-- __rel_dyn_end |
| |
| b 2f # skip first reserved entry |
| PTR_ADDIU t1, 2 * PTRSIZE |
| |
| 1: |
| lw t8, -4(t1) # t8 <-- relocation info |
| |
| PTR_LI t3, MIPS_RELOC |
| bne t8, t3, 2f # skip non-MIPS_RELOC entries |
| nop |
| |
| PTR_L t3, -(2 * PTRSIZE)(t1) # t3 <-- location to fix up in FLASH |
| |
| PTR_L t8, 0(t3) # t8 <-- original pointer |
| PTR_ADD t8, s1 # t8 <-- adjusted pointer |
| |
| PTR_ADD t3, s1 # t3 <-- location to fix up in RAM |
| PTR_S t8, 0(t3) |
| |
| 2: |
| blt t1, t2, 1b |
| PTR_ADDIU t1, 2 * PTRSIZE # each rel.dyn entry is 2*PTRSIZE bytes |
| |
| /* |
| * Clear BSS |
| * |
| * GOT is now relocated. Thus __bss_start and __bss_end can be |
| * accessed directly via $gp. |
| */ |
| PTR_LA t1, __bss_start # t1 <-- __bss_start |
| PTR_LA t2, __bss_end # t2 <-- __bss_end |
| |
| 1: |
| PTR_S zero, 0(t1) |
| blt t1, t2, 1b |
| PTR_ADDIU t1, PTRSIZE |
| |
| move a0, s0 # a0 <-- gd |
| move a1, s2 |
| PTR_LA t9, board_init_r |
| jr t9 |
| move ra, zero |
| |
| END(relocate_code) |