/* SPDX-License-Identifier: GPL-2.0+ */ /* * Startup Code for RISC-V Core * * Copyright (c) 2017 Microsemi Corporation. * Copyright (c) 2017 Padmarao Begari * * Copyright (C) 2017 Andes Technology Corporation * Rick Chen, Andes Technology Corporation */ #include #include #include #include #include #ifdef CONFIG_32BIT #define LREG lw #define SREG sw #define REGBYTES 4 #define RELOC_TYPE R_RISCV_32 #define SYM_INDEX 0x8 #define SYM_SIZE 0x10 #else #define LREG ld #define SREG sd #define REGBYTES 8 #define RELOC_TYPE R_RISCV_64 #define SYM_INDEX 0x20 #define SYM_SIZE 0x18 #endif .section .text .globl _start _start: /* save hart id and dtb pointer */ mv s0, a0 mv s1, a1 li t0, CONFIG_SYS_SDRAM_BASE SREG a2, 0(t0) la t0, trap_entry csrw mtvec, t0 /* mask all interrupts */ csrw mie, zero /* * Set stackpointer in internal/ex RAM to call board_init_f */ call_board_init_f: li t0, -16 li t1, CONFIG_SYS_INIT_SP_ADDR and sp, t1, t0 /* force 16 byte alignment */ #ifdef CONFIG_DEBUG_UART jal debug_uart_init #endif call_board_init_f_0: mv a0, sp jal board_init_f_alloc_reserve mv sp, a0 la t0, prior_stage_fdt_address SREG s1, 0(t0) jal board_init_f_init_reserve mv a0, zero /* a0 <-- boot_flags = 0 */ la t5, board_init_f jr t5 /* jump to board_init_f() */ /* * void relocate_code (addr_sp, gd, addr_moni) * * This "function" does not return, instead it continues in RAM * after relocating the monitor code. * */ .globl relocate_code relocate_code: mv s2, a0 /* save addr_sp */ mv s3, a1 /* save addr of gd */ mv s4, a2 /* save addr of destination */ /* *Set up the stack */ stack_setup: mv sp, s2 la t0, _start sub t6, s4, t0 /* t6 <- relocation offset */ beq t0, s4, clear_bss /* skip relocation */ mv t1, s4 /* t1 <- scratch for copy_loop */ la t3, __bss_start sub t3, t3, t0 /* t3 <- __bss_start_ofs */ add t2, t0, t3 /* t2 <- source end address */ copy_loop: LREG t5, 0(t0) addi t0, t0, REGBYTES SREG t5, 0(t1) addi t1, t1, REGBYTES blt t0, t2, copy_loop /* * Update dynamic relocations after board_init_f */ fix_rela_dyn: la t1, __rel_dyn_start la t2, __rel_dyn_end beq t1, t2, clear_bss add t1, t1, t6 /* t1 <- rela_dyn_start in RAM */ add t2, t2, t6 /* t2 <- rela_dyn_end in RAM */ /* * skip first reserved entry: address, type, addend */ bne t1, t2, 7f 6: LREG t5, -(REGBYTES*2)(t1) /* t5 <-- relocation info:type */ li t3, R_RISCV_RELATIVE /* reloc type R_RISCV_RELATIVE */ bne t5, t3, 8f /* skip non-RISCV_RELOC entries */ LREG t3, -(REGBYTES*3)(t1) LREG t5, -(REGBYTES)(t1) /* t5 <-- addend */ add t5, t5, t6 /* t5 <-- location to fix up in RAM */ add t3, t3, t6 /* t3 <-- location to fix up in RAM */ SREG t5, 0(t3) 7: addi t1, t1, (REGBYTES*3) ble t1, t2, 6b 8: la t4, __dyn_sym_start add t4, t4, t6 9: LREG t5, -(REGBYTES*2)(t1) /* t5 <-- relocation info:type */ srli t0, t5, SYM_INDEX /* t0 <--- sym table index */ andi t5, t5, 0xFF /* t5 <--- relocation type */ li t3, RELOC_TYPE bne t5, t3, 10f /* skip non-addned entries */ LREG t3, -(REGBYTES*3)(t1) li t5, SYM_SIZE mul t0, t0, t5 add s5, t4, t0 LREG t5, REGBYTES(s5) add t5, t5, t6 /* t5 <-- location to fix up in RAM */ add t3, t3, t6 /* t3 <-- location to fix up in RAM */ SREG t5, 0(t3) 10: addi t1, t1, (REGBYTES*3) ble t1, t2, 9b /* * trap update */ la t0, trap_entry add t0, t0, t6 csrw mtvec, t0 clear_bss: la t0, __bss_start /* t0 <- rel __bss_start in FLASH */ add t0, t0, t6 /* t0 <- rel __bss_start in RAM */ la t1, __bss_end /* t1 <- rel __bss_end in FLASH */ add t1, t1, t6 /* t1 <- rel __bss_end in RAM */ beq t0, t1, call_board_init_r clbss_l: SREG zero, 0(t0) /* clear loop... */ addi t0, t0, REGBYTES bne t0, t1, clbss_l /* * We are done. Do not return, instead branch to second part of board * initialization, now running from RAM. */ call_board_init_r: la t0, board_init_r mv t4, t0 /* offset of board_init_r() */ add t4, t4, t6 /* real address of board_init_r() */ /* * setup parameters for board_init_r */ mv a0, s3 /* gd_t */ mv a1, s4 /* dest_addr */ /* * jump to it ... */ jr t4 /* jump to board_init_r() */ /* * trap entry */ .align 2 trap_entry: addi sp, sp, -32*REGBYTES SREG x1, 1*REGBYTES(sp) SREG x2, 2*REGBYTES(sp) SREG x3, 3*REGBYTES(sp) SREG x4, 4*REGBYTES(sp) SREG x5, 5*REGBYTES(sp) SREG x6, 6*REGBYTES(sp) SREG x7, 7*REGBYTES(sp) SREG x8, 8*REGBYTES(sp) SREG x9, 9*REGBYTES(sp) SREG x10, 10*REGBYTES(sp) SREG x11, 11*REGBYTES(sp) SREG x12, 12*REGBYTES(sp) SREG x13, 13*REGBYTES(sp) SREG x14, 14*REGBYTES(sp) SREG x15, 15*REGBYTES(sp) SREG x16, 16*REGBYTES(sp) SREG x17, 17*REGBYTES(sp) SREG x18, 18*REGBYTES(sp) SREG x19, 19*REGBYTES(sp) SREG x20, 20*REGBYTES(sp) SREG x21, 21*REGBYTES(sp) SREG x22, 22*REGBYTES(sp) SREG x23, 23*REGBYTES(sp) SREG x24, 24*REGBYTES(sp) SREG x25, 25*REGBYTES(sp) SREG x26, 26*REGBYTES(sp) SREG x27, 27*REGBYTES(sp) SREG x28, 28*REGBYTES(sp) SREG x29, 29*REGBYTES(sp) SREG x30, 30*REGBYTES(sp) SREG x31, 31*REGBYTES(sp) csrr a0, mcause csrr a1, mepc mv a2, sp jal handle_trap csrw mepc, a0 /* * Remain in M-mode after mret */ li t0, MSTATUS_MPP csrs mstatus, t0 LREG x1, 1*REGBYTES(sp) LREG x2, 2*REGBYTES(sp) LREG x3, 3*REGBYTES(sp) LREG x4, 4*REGBYTES(sp) LREG x5, 5*REGBYTES(sp) LREG x6, 6*REGBYTES(sp) LREG x7, 7*REGBYTES(sp) LREG x8, 8*REGBYTES(sp) LREG x9, 9*REGBYTES(sp) LREG x10, 10*REGBYTES(sp) LREG x11, 11*REGBYTES(sp) LREG x12, 12*REGBYTES(sp) LREG x13, 13*REGBYTES(sp) LREG x14, 14*REGBYTES(sp) LREG x15, 15*REGBYTES(sp) LREG x16, 16*REGBYTES(sp) LREG x17, 17*REGBYTES(sp) LREG x18, 18*REGBYTES(sp) LREG x19, 19*REGBYTES(sp) LREG x20, 20*REGBYTES(sp) LREG x21, 21*REGBYTES(sp) LREG x22, 22*REGBYTES(sp) LREG x23, 23*REGBYTES(sp) LREG x24, 24*REGBYTES(sp) LREG x25, 25*REGBYTES(sp) LREG x26, 26*REGBYTES(sp) LREG x27, 27*REGBYTES(sp) LREG x28, 28*REGBYTES(sp) LREG x29, 29*REGBYTES(sp) LREG x30, 30*REGBYTES(sp) LREG x31, 31*REGBYTES(sp) addi sp, sp, 32*REGBYTES mret