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opensbi/firmware/fw_common.S
Anup Patel ef5f4e149c firmware: Remove redundant write to mideleg and medeleg 
The mideleg and medeleg are already programmed in delegate_traps()
so no need to set it here.

Any CSR setup in our reference firmware becomes a requirement
for bootloader linking to libsbi.a so we should have minimum
possible CSR setup in our reference firmware.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2018-12-21 15:05:59 +05:30

326 lines
8.1 KiB
ArmAsm
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/*
* Copyright (c) 2018 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <sbi/riscv_asm.h>
#include <sbi/riscv_encoding.h>
.align 3
.section .entry, "ax", %progbits
.globl _start
.globl _start_warm
_start:
/*
* Jump to warm-boot if this is not the first core booting,
* that is, for mhartid != 0
*/
csrr a6, mhartid
blt zero, a6, _wait_for_boot_hart
/* Zero-out BSS */
la a4, _bss_start
la a5, _bss_end
_bss_zero:
REG_S zero, (a4)
add a4, a4, __SIZEOF_POINTER__
blt a4, a5, _bss_zero
/* Override pervious arg1 */
add s0, a0, zero
add s1, a1, zero
call fw_prev_arg1
add t1, a0, zero
add a0, s0, zero
add a1, s1, zero
beqz t1, _prev_arg1_override_done
add a1, t1, zero
_prev_arg1_override_done:
/*
* Relocate Flatened Device Tree (FDT)
* source FDT address = previous arg1
* destination FDT address = next arg1
*
* Note: We will preserve a0 and a1 passed by
* previous booting stage.
*/
beqz a1, _fdt_reloc_done
/* Mask values in a3 and a4 */
li a3, ~0xf
li a4, 0xff
/* t1 = destination FDT start address */
add s0, a0, zero
add s1, a1, zero
call fw_next_arg1
add t1, a0, zero
add a0, s0, zero
add a1, s1, zero
beqz t1, _fdt_reloc_done
and t1, t1, a3
/* t0 = source FDT start address */
add t0, a1, zero
and t0, t0, a3
/* t2 = source FDT size in big-endian */
lwu t2, 4(t0)
/* t3 = bit[15:8] of FDT size */
add t3, t2, zero
srli t3, t3, 16
and t3, t3, a4
slli t3, t3, 8
/* t4 = bit[23:16] of FDT size */
add t4, t2, zero
srli t4, t4, 8
and t4, t4, a4
slli t4, t4, 16
/* t5 = bit[31:24] of FDT size */
add t5, t2, zero
and t5, t5, a4
slli t5, t5, 24
/* t2 = bit[7:0] of FDT size */
srli t2, t2, 24
and t2, t2, a4
/* t2 = FDT size in little-endian */
or t2, t2, t3
or t2, t2, t4
or t2, t2, t5
/* t2 = destination FDT end address */
add t2, t1, t2
/* FDT copy loop */
ble t2, t1, _fdt_reloc_done
_fdt_reloc_again:
REG_L t3, 0(t0)
REG_S t3, 0(t1)
add t0, t0, __SIZEOF_POINTER__
add t1, t1, __SIZEOF_POINTER__
blt t1, t2, _fdt_reloc_again
_fdt_reloc_done:
/* Update boot hart flag */
la a4, _boot_hart_done
li a5, 1
REG_S a5, (a4)
j _wait_for_boot_hart
.align 3
_boot_hart_done:
RISCV_PTR 0
.align 3
/* Wait for boot hart */
_wait_for_boot_hart:
la a4, _boot_hart_done
REG_L a5, (a4)
beqz a5, _wait_for_boot_hart
_start_warm:
/* Disable and clear all interrupts */
csrw mie, zero
csrw mip, zero
/* set MSIE bit to receive IPI */
li a2, MIP_MSIP
csrw mie, a2
/* HART ID should be within expected limit */
csrr a6, mhartid
li a5, PLAT_HART_COUNT
bge a6, a5, _start_hang
/* Setup scratch space */
li a5, PLAT_HART_STACK_SIZE
la tp, _stack_end
mul a5, a5, a6
sub tp, tp, a5
li a5, RISCV_SCRATCH_SIZE
sub tp, tp, a5
csrw mscratch, tp
/* Initialize scratch space */
REG_S zero, RISCV_SCRATCH_TMP0_OFFSET(tp)
la a4, _fw_start
la a5, _fw_end
sub a5, a5, a4
REG_S a4, RISCV_SCRATCH_FW_START_OFFSET(tp)
REG_S a5, RISCV_SCRATCH_FW_SIZE_OFFSET(tp)
/* Note: fw_next_arg1() uses a0, a1, and ra */
call fw_next_arg1
REG_S a0, RISCV_SCRATCH_NEXT_ARG1_OFFSET(tp)
/* Note: fw_next_addr() uses a0, a1, and ra */
call fw_next_addr
REG_S a0, RISCV_SCRATCH_NEXT_ADDR_OFFSET(tp)
li a4, PRV_S
REG_S a4, RISCV_SCRATCH_NEXT_MODE_OFFSET(tp)
la a4, _start_warm
REG_S a4, RISCV_SCRATCH_WARMBOOT_ADDR_OFFSET(tp)
la a4, platform
REG_S a4, RISCV_SCRATCH_PLATFORM_ADDR_OFFSET(tp)
la a4, _hartid_to_scratch
REG_S a4, RISCV_SCRATCH_HARTID_TO_SCRATCH_OFFSET(tp)
REG_S zero, RISCV_SCRATCH_IPI_TYPE_OFFSET(tp)
/* Setup stack */
add sp, tp, zero
/* Setup trap handler */
la a4, _trap_handler
csrw mtvec, a4
/* Initialize SBI runtime */
csrr a0, mscratch
call sbi_init
/* We don't expect to reach here hence just hang */
j _start_hang
.align 3
.section .entry, "ax", %progbits
.globl _hartid_to_scratch
_hartid_to_scratch:
add sp, sp, -(2 * __SIZEOF_POINTER__)
REG_S a1, (sp)
REG_S a2, (__SIZEOF_POINTER__)(sp)
li a1, PLAT_HART_STACK_SIZE
la a2, _stack_end
mul a1, a1, a0
sub a2, a2, a1
li a1, RISCV_SCRATCH_SIZE
sub a0, a2, a1
REG_L a1, (sp)
REG_L a2, (__SIZEOF_POINTER__)(sp)
add sp, sp, (2 * __SIZEOF_POINTER__)
ret
.align 3
.section .entry, "ax", %progbits
.globl _start_hang
_start_hang:
wfi
j _start_hang
.align 3
.section .entry, "ax", %progbits
.globl _trap_handler
_trap_handler:
/* Swap SP and MSCRATCH */
csrrw sp, mscratch, sp
/* Setup exception stack */
add sp, sp, -(RISCV_TRAP_REGS_SIZE)
/* Save RA, T0, T1, and T2 */
REG_S ra, RISCV_TRAP_REGS_OFFSET(ra)(sp)
REG_S t0, RISCV_TRAP_REGS_OFFSET(t0)(sp)
REG_S t1, RISCV_TRAP_REGS_OFFSET(t1)(sp)
REG_S t2, RISCV_TRAP_REGS_OFFSET(t2)(sp)
/* Save original SP and restore MSCRATCH */
add t0, sp, RISCV_TRAP_REGS_SIZE
csrrw t0, mscratch, t0
REG_S t0, RISCV_TRAP_REGS_OFFSET(sp)(sp)
/* Save MEPC and MSTATUS CSRs */
csrr t0, mepc
csrr t1, mstatus
/*
* Note: Fast path trap handling can be done here
* using SP, RA, T0, T1, and T2 registers where
* T0 <- MEPC
* T1 <- MSTATUS
*/
/* Save MEPC and MSTATUS CSRs */
REG_S t0, RISCV_TRAP_REGS_OFFSET(mepc)(sp)
REG_S t1, RISCV_TRAP_REGS_OFFSET(mstatus)(sp)
/* Save all general regisers except SP, RA, T0, T1, and T2 */
REG_S zero, RISCV_TRAP_REGS_OFFSET(zero)(sp)
REG_S gp, RISCV_TRAP_REGS_OFFSET(gp)(sp)
REG_S tp, RISCV_TRAP_REGS_OFFSET(tp)(sp)
REG_S s0, RISCV_TRAP_REGS_OFFSET(s0)(sp)
REG_S s1, RISCV_TRAP_REGS_OFFSET(s1)(sp)
REG_S a0, RISCV_TRAP_REGS_OFFSET(a0)(sp)
REG_S a1, RISCV_TRAP_REGS_OFFSET(a1)(sp)
REG_S a2, RISCV_TRAP_REGS_OFFSET(a2)(sp)
REG_S a3, RISCV_TRAP_REGS_OFFSET(a3)(sp)
REG_S a4, RISCV_TRAP_REGS_OFFSET(a4)(sp)
REG_S a5, RISCV_TRAP_REGS_OFFSET(a5)(sp)
REG_S a6, RISCV_TRAP_REGS_OFFSET(a6)(sp)
REG_S a7, RISCV_TRAP_REGS_OFFSET(a7)(sp)
REG_S s2, RISCV_TRAP_REGS_OFFSET(s2)(sp)
REG_S s3, RISCV_TRAP_REGS_OFFSET(s3)(sp)
REG_S s4, RISCV_TRAP_REGS_OFFSET(s4)(sp)
REG_S s5, RISCV_TRAP_REGS_OFFSET(s5)(sp)
REG_S s6, RISCV_TRAP_REGS_OFFSET(s6)(sp)
REG_S s7, RISCV_TRAP_REGS_OFFSET(s7)(sp)
REG_S s8, RISCV_TRAP_REGS_OFFSET(s8)(sp)
REG_S s9, RISCV_TRAP_REGS_OFFSET(s9)(sp)
REG_S s10, RISCV_TRAP_REGS_OFFSET(s10)(sp)
REG_S s11, RISCV_TRAP_REGS_OFFSET(s11)(sp)
REG_S t3, RISCV_TRAP_REGS_OFFSET(t3)(sp)
REG_S t4, RISCV_TRAP_REGS_OFFSET(t4)(sp)
REG_S t5, RISCV_TRAP_REGS_OFFSET(t5)(sp)
REG_S t6, RISCV_TRAP_REGS_OFFSET(t6)(sp)
/* Call C routine */
add a0, sp, zero
csrr a1, mscratch
call sbi_trap_handler
/* Restore all general regisers except SP, RA, T0, T1, T2, and T3 */
REG_L gp, RISCV_TRAP_REGS_OFFSET(gp)(sp)
REG_L tp, RISCV_TRAP_REGS_OFFSET(tp)(sp)
REG_L s0, RISCV_TRAP_REGS_OFFSET(s0)(sp)
REG_L s1, RISCV_TRAP_REGS_OFFSET(s1)(sp)
REG_L a0, RISCV_TRAP_REGS_OFFSET(a0)(sp)
REG_L a1, RISCV_TRAP_REGS_OFFSET(a1)(sp)
REG_L a2, RISCV_TRAP_REGS_OFFSET(a2)(sp)
REG_L a3, RISCV_TRAP_REGS_OFFSET(a3)(sp)
REG_L a4, RISCV_TRAP_REGS_OFFSET(a4)(sp)
REG_L a5, RISCV_TRAP_REGS_OFFSET(a5)(sp)
REG_L a6, RISCV_TRAP_REGS_OFFSET(a6)(sp)
REG_L a7, RISCV_TRAP_REGS_OFFSET(a7)(sp)
REG_L s2, RISCV_TRAP_REGS_OFFSET(s2)(sp)
REG_L s3, RISCV_TRAP_REGS_OFFSET(s3)(sp)
REG_L s4, RISCV_TRAP_REGS_OFFSET(s4)(sp)
REG_L s5, RISCV_TRAP_REGS_OFFSET(s5)(sp)
REG_L s6, RISCV_TRAP_REGS_OFFSET(s6)(sp)
REG_L s7, RISCV_TRAP_REGS_OFFSET(s7)(sp)
REG_L s8, RISCV_TRAP_REGS_OFFSET(s8)(sp)
REG_L s9, RISCV_TRAP_REGS_OFFSET(s9)(sp)
REG_L s10, RISCV_TRAP_REGS_OFFSET(s10)(sp)
REG_L s11, RISCV_TRAP_REGS_OFFSET(s11)(sp)
REG_L t3, RISCV_TRAP_REGS_OFFSET(t3)(sp)
REG_L t4, RISCV_TRAP_REGS_OFFSET(t4)(sp)
REG_L t5, RISCV_TRAP_REGS_OFFSET(t5)(sp)
REG_L t6, RISCV_TRAP_REGS_OFFSET(t6)(sp)
/* Load T0 and T1 with MEPC and MSTATUS */
REG_L t0, RISCV_TRAP_REGS_OFFSET(mepc)(sp)
REG_L t1, RISCV_TRAP_REGS_OFFSET(mstatus)(sp)
/*
* Note: Jump here after fast trap handling
* using SP, RA, T0, T1, and T2
* T0 <- MEPC
* T1 <- MSTATUS
*/
/* Restore MEPC and MSTATUS CSRs */
csrw mepc, t0
csrw mstatus, t1
/* Restore RA, T0, T1, and T2 */
REG_L ra, RISCV_TRAP_REGS_OFFSET(ra)(sp)
REG_L t0, RISCV_TRAP_REGS_OFFSET(t0)(sp)
REG_L t1, RISCV_TRAP_REGS_OFFSET(t1)(sp)
REG_L t2, RISCV_TRAP_REGS_OFFSET(t2)(sp)
/* Restore SP */
REG_L sp, RISCV_TRAP_REGS_OFFSET(sp)(sp)
mret
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