diff options
Diffstat (limited to 'arch/arc/lib/start.S')
| -rw-r--r-- | arch/arc/lib/start.S | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/arch/arc/lib/start.S b/arch/arc/lib/start.S new file mode 100644 index 0000000000..39eace36a9 --- /dev/null +++ b/arch/arc/lib/start.S @@ -0,0 +1,241 @@ +/* + * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <asm-offsets.h> +#include <config.h> +#include <linux/linkage.h> +#include <asm/arcregs.h> + +/* + * Note on the LD/ST addressing modes with address register write-back + * + * LD.a same as LD.aw + * + * LD.a reg1, [reg2, x] => Pre Incr + * Eff Addr for load = [reg2 + x] + * + * LD.ab reg1, [reg2, x] => Post Incr + * Eff Addr for load = [reg2] + */ + +.macro PUSH reg + st.a \reg, [%sp, -4] +.endm + +.macro PUSHAX aux + lr %r9, [\aux] + PUSH %r9 +.endm + +.macro SAVE_R1_TO_R24 + PUSH %r1 + PUSH %r2 + PUSH %r3 + PUSH %r4 + PUSH %r5 + PUSH %r6 + PUSH %r7 + PUSH %r8 + PUSH %r9 + PUSH %r10 + PUSH %r11 + PUSH %r12 + PUSH %r13 + PUSH %r14 + PUSH %r15 + PUSH %r16 + PUSH %r17 + PUSH %r18 + PUSH %r19 + PUSH %r20 + PUSH %r21 + PUSH %r22 + PUSH %r23 + PUSH %r24 +.endm + +.macro SAVE_ALL_SYS + /* saving %r0 to reg->r0 in advance since we read %ecr into it */ + st %r0, [%sp, -8] + lr %r0, [%ecr] /* all stack addressing is manual so far */ + st %r0, [%sp] + st %sp, [%sp, -4] + /* now move %sp to reg->r0 position so we can do "push" automatically */ + sub %sp, %sp, 8 + + SAVE_R1_TO_R24 + PUSH %r25 + PUSH %gp + PUSH %fp + PUSH %blink + PUSHAX %eret + PUSHAX %erstatus + PUSH %lp_count + PUSHAX %lp_end + PUSHAX %lp_start + PUSHAX %erbta +.endm + +.macro SAVE_EXCEPTION_SOURCE +#ifdef CONFIG_MMU + /* If MMU exists exception faulting address is loaded in EFA reg */ + lr %r0, [%efa] +#else + /* Otherwise in ERET (exception return) reg */ + lr %r0, [%eret] +#endif +.endm + +ENTRY(_start) + /* Setup interrupt vector base that matches "__text_start" */ + sr __ivt_start, [ARC_AUX_INTR_VEC_BASE] + + /* Setup stack pointer */ + mov %sp, CONFIG_SYS_INIT_SP_ADDR + mov %fp, %sp + + /* Clear bss */ + mov %r0, __bss_start + mov %r1, __bss_end + +clear_bss: + st.ab 0, [%r0, 4] + brlt %r0, %r1, clear_bss + + /* Zero the one and only argument of "board_init_f" */ + mov_s %r0, 0 + j board_init_f +ENDPROC(_start) + +ENTRY(memory_error) + SAVE_ALL_SYS + SAVE_EXCEPTION_SOURCE + mov %r1, %sp + j do_memory_error +ENDPROC(memory_error) + +ENTRY(instruction_error) + SAVE_ALL_SYS + SAVE_EXCEPTION_SOURCE + mov %r1, %sp + j do_instruction_error +ENDPROC(instruction_error) + +ENTRY(interrupt_handler) + /* Todo - save and restore CPU context when interrupts will be in use */ + bl do_interrupt_handler + rtie +ENDPROC(interrupt_handler) + +ENTRY(EV_MachineCheck) + SAVE_ALL_SYS + SAVE_EXCEPTION_SOURCE + mov %r1, %sp + j do_machine_check_fault +ENDPROC(EV_MachineCheck) + +ENTRY(EV_TLBMissI) + SAVE_ALL_SYS + mov %r0, %sp + j do_itlb_miss +ENDPROC(EV_TLBMissI) + +ENTRY(EV_TLBMissD) + SAVE_ALL_SYS + mov %r0, %sp + j do_dtlb_miss +ENDPROC(EV_TLBMissD) + +ENTRY(EV_TLBProtV) + SAVE_ALL_SYS + SAVE_EXCEPTION_SOURCE + mov %r1, %sp + j do_tlb_prot_violation +ENDPROC(EV_TLBProtV) + +ENTRY(EV_PrivilegeV) + SAVE_ALL_SYS + mov %r0, %sp + j do_privilege_violation +ENDPROC(EV_PrivilegeV) + +ENTRY(EV_Trap) + SAVE_ALL_SYS + mov %r0, %sp + j do_trap +ENDPROC(EV_Trap) + +ENTRY(EV_Extension) + SAVE_ALL_SYS + mov %r0, %sp + j do_extension +ENDPROC(EV_Extension) + +/* + * void relocate_code (addr_sp, gd, addr_moni) + * + * This "function" does not return, instead it continues in RAM + * after relocating the monitor code. + * + * r0 = start_addr_sp + * r1 = new__gd + * r2 = relocaddr + */ +ENTRY(relocate_code) + /* + * r0-r12 might be clobbered by C functions + * so we use r13-r16 for storage here + */ + mov %r13, %r0 /* save addr_sp */ + mov %r14, %r1 /* save addr of gd */ + mov %r15, %r2 /* save addr of destination */ + + mov %r16, %r2 /* %r9 - relocation offset */ + sub %r16, %r16, __image_copy_start + +/* Set up the stack */ +stack_setup: + mov %sp, %r13 + mov %fp, %sp + +/* Check if monitor is loaded right in place for relocation */ + mov %r0, __image_copy_start + cmp %r0, %r15 /* skip relocation if code loaded */ + bz do_board_init_r /* in target location already */ + +/* Copy data (__image_copy_start - __image_copy_end) to new location */ + mov %r1, %r15 + mov %r2, __image_copy_end + sub %r2, %r2, %r0 /* r3 <- amount of bytes to copy */ + asr %r2, %r2, 2 /* r3 <- amount of words to copy */ + mov %lp_count, %r2 + lp copy_end + ld.ab %r2,[%r0,4] + st.ab %r2,[%r1,4] +copy_end: + +/* Fix relocations related issues */ + bl do_elf_reloc_fixups +#ifndef CONFIG_SYS_ICACHE_OFF + bl invalidate_icache_all +#endif +#ifndef CONFIG_SYS_DCACHE_OFF + bl flush_dcache_all +#endif + +/* Update position of intterupt vector table */ + lr %r0, [ARC_AUX_INTR_VEC_BASE] /* Read current position */ + add %r0, %r0, %r16 /* Update address */ + sr %r0, [ARC_AUX_INTR_VEC_BASE] /* Write new position */ + +do_board_init_r: +/* Prepare for exection of "board_init_r" in relocated monitor */ + mov %r2, board_init_r /* old address of "board_init_r()" */ + add %r2, %r2, %r16 /* new address of "board_init_r()" */ + mov %r0, %r14 /* 1-st parameter: gd_t */ + mov %r1, %r15 /* 2-nd parameter: dest_addr */ + j [%r2] +ENDPROC(relocate_code) |