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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Startup Code for RISC-V Core
*
* Copyright (c) 2017 Microsemi Corporation.
* Copyright (c) 2017 Padmarao Begari <Padmarao.Begari@microsemi.com>
*
* Copyright (C) 2017 Andes Technology Corporation
* Rick Chen, Andes Technology Corporation <rick@andestech.com>
*/
#include <asm-offsets.h>
#include <config.h>
#include <common.h>
#include <elf.h>
#include <asm/csr.h>
#include <asm/encoding.h>
#include <generated/asm-offsets.h>
#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 .data
secondary_harts_relocation_error:
.ascii "Relocation of secondary harts has failed, error %d\n"
.section .text
.globl _start
_start:
#ifdef CONFIG_RISCV_MMODE
csrr a0, mhartid
#endif
/* save hart id and dtb pointer */
mv tp, a0
mv s1, a1
la t0, trap_entry
csrw MODE_PREFIX(tvec), t0
/* mask all interrupts */
csrw MODE_PREFIX(ie), zero
#ifdef CONFIG_SMP
/* check if hart is within range */
/* tp: hart id */
li t0, CONFIG_NR_CPUS
bge tp, t0, hart_out_of_bounds_loop
#endif
#ifdef CONFIG_SMP
/* set xSIE bit to receive IPIs */
#ifdef CONFIG_RISCV_MMODE
li t0, MIE_MSIE
#else
li t0, SIE_SSIE
#endif
csrs MODE_PREFIX(ie), t0
#endif
/*
* 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 */
call_board_init_f_0:
mv a0, sp
jal board_init_f_alloc_reserve
/*
* Set global data pointer here for all harts, uninitialized at this
* point.
*/
mv gp, a0
/* setup stack */
#ifdef CONFIG_SMP
/* tp: hart id */
slli t0, tp, CONFIG_STACK_SIZE_SHIFT
sub sp, a0, t0
#else
mv sp, a0
#endif
#ifndef CONFIG_XIP
/*
* Pick hart to initialize global data and run U-Boot. The other harts
* wait for initialization to complete.
*/
la t0, hart_lottery
li s2, 1
amoswap.w s2, t1, 0(t0)
bnez s2, wait_for_gd_init
#else
bnez tp, secondary_hart_loop
#endif
#ifdef CONFIG_OF_PRIOR_STAGE
la t0, prior_stage_fdt_address
SREG s1, 0(t0)
#endif
jal board_init_f_init_reserve
/* save the boot hart id to global_data */
SREG tp, GD_BOOT_HART(gp)
#ifndef CONFIG_XIP
la t0, available_harts_lock
fence rw, w
amoswap.w zero, zero, 0(t0)
wait_for_gd_init:
la t0, available_harts_lock
li t1, 1
1: amoswap.w t1, t1, 0(t0)
fence r, rw
bnez t1, 1b
/* register available harts in the available_harts mask */
li t1, 1
sll t1, t1, tp
LREG t2, GD_AVAILABLE_HARTS(gp)
or t2, t2, t1
SREG t2, GD_AVAILABLE_HARTS(gp)
fence rw, w
amoswap.w zero, zero, 0(t0)
/*
* Continue on hart lottery winner, others branch to
* secondary_hart_loop.
*/
bnez s2, secondary_hart_loop
#endif
/* Enable cache */
jal icache_enable
jal dcache_enable
#ifdef CONFIG_DEBUG_UART
jal debug_uart_init
#endif
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:
#ifdef CONFIG_SMP
/* tp: hart id */
slli t0, tp, CONFIG_STACK_SIZE_SHIFT
sub sp, s2, t0
#else
mv sp, s2
#endif
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 MODE_PREFIX(tvec), 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, relocate_secondary_harts
clbss_l:
SREG zero, 0(t0) /* clear loop... */
addi t0, t0, REGBYTES
bne t0, t1, clbss_l
relocate_secondary_harts:
#ifdef CONFIG_SMP
/* send relocation IPI */
la t0, secondary_hart_relocate
add a0, t0, t6
/* store relocation offset */
mv s5, t6
mv a1, s2
mv a2, s3
jal smp_call_function
/* hang if relocation of secondary harts has failed */
beqz a0, 1f
mv a1, a0
la a0, secondary_harts_relocation_error
jal printf
jal hang
/* restore relocation offset */
1: mv t6, s5
#endif
/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
call_board_init_r:
jal invalidate_icache_all
jal flush_dcache_all
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() */
#ifdef CONFIG_SMP
hart_out_of_bounds_loop:
/* Harts in this loop are out of bounds, increase CONFIG_NR_CPUS. */
wfi
j hart_out_of_bounds_loop
#endif
#ifdef CONFIG_SMP
/* SMP relocation entry */
secondary_hart_relocate:
/* a1: new sp */
/* a2: new gd */
/* tp: hart id */
/* setup stack */
slli t0, tp, CONFIG_STACK_SIZE_SHIFT
sub sp, a1, t0
/* update global data pointer */
mv gp, a2
#endif
secondary_hart_loop:
wfi
#ifdef CONFIG_SMP
csrr t0, MODE_PREFIX(ip)
#ifdef CONFIG_RISCV_MMODE
andi t0, t0, MIE_MSIE
#else
andi t0, t0, SIE_SSIE
#endif
beqz t0, secondary_hart_loop
mv a0, tp
jal handle_ipi
#endif
j secondary_hart_loop