diff options
| -rw-r--r-- | arch/riscv/Kconfig | 24 | ||||
| -rw-r--r-- | arch/riscv/boot/start.S | 8 | ||||
| -rw-r--r-- | arch/riscv/include/asm/riscv_nmon.h | 234 |
3 files changed, 266 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index ee532ac11a..f1e69377e5 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -63,3 +63,27 @@ config BUILTIN_DTB_NAME source arch/riscv/mach-erizo/Kconfig endmenu + +menu "RISC-V specific settings" + +config HAS_NMON + bool + +config NMON + bool "nmon" + depends on HAS_NMON + depends on DEBUG_LL + help + Say yes here to add the nmon to pbl. + nmon -- nano-monitor program for the RISC-V processors. + It can operate with NO working RAM, using only + the processor registers. + +config NMON_HELP + bool "nmon help message" + depends on NMON + help + Say yes here to get the nmon commands message on + every nmon start. + +endmenu diff --git a/arch/riscv/boot/start.S b/arch/riscv/boot/start.S index d13708740b..d1dbe48b7b 100644 --- a/arch/riscv/boot/start.S +++ b/arch/riscv/boot/start.S @@ -18,12 +18,20 @@ #include <asm-generic/memory_layout.h> +#include "mach/debug_ll.h" + +#include "asm/riscv_nmon.h" + .text .section ".text_entry" .align 2 .globl _start _start: + debug_ll_ns16550_init + + riscv_nmon + li sp, STACK_BASE + STACK_SIZE /* copy barebox to link location */ diff --git a/arch/riscv/include/asm/riscv_nmon.h b/arch/riscv/include/asm/riscv_nmon.h new file mode 100644 index 0000000000..caf213cdd8 --- /dev/null +++ b/arch/riscv/include/asm/riscv_nmon.h @@ -0,0 +1,234 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * nano-monitor for RISC-V CPU + * + * Copyright (C) 2016, 2017 Antony Pavlov <antonynpavlov@gmail.com> + * + * This file is part of barebox. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#ifndef __ASM_RISCV_NMON_H +#define __ASM_RISCV_NMON_H + +#define CODE_ESC 0x1b + +.macro nmon_outs msg + + la a1, \msg + + jal _nmon_outs + +.endm + +/* + * output a 32-bit value in hex + */ +.macro debug_ll_outhexw +#ifdef CONFIG_DEBUG_LL + move t6, a0 + li t5, 32 + +202: + addi t5, t5, -4 + srl a0, t6, t5 + + /* output one hex digit */ + andi a0, a0, 15 + li t4, 10 + blt a0, t4, 203f + + addi a0, a0, ('a' - '9' - 1) + +203: + addi a0, a0, '0' + + debug_ll_outc_a0 + + li t4, 1 + bge t5, t4, 202b + +#endif /* CONFIG_DEBUG_LL */ +.endm + +.macro riscv_nmon + +#ifdef CONFIG_NMON + +nmon_main_help: +#ifdef CONFIG_NMON_HELP + nmon_outs msg_nmon_help +#endif /* CONFIG_NMON_HELP */ + +nmon_main: + nmon_outs msg_prompt + + debug_ll_getc + + li a0, 'q' + bne s0, a0, 3f + + jal _nmon_outc_a0 + + j nmon_exit + +3: + li a0, 'd' + beq s0, a0, nmon_cmd_d + + li a0, 'w' + beq s0, a0, nmon_cmd_w + + li a0, 'g' + beq s0, a0, nmon_cmd_g + + j nmon_main_help + +nmon_cmd_d: + jal _nmon_outc_a0 + + li a0, ' ' + jal _nmon_outc_a0 + + jal _nmon_gethexw + + nmon_outs msg_nl + + lw a0, (s0) + debug_ll_outhexw + + j nmon_main + +nmon_cmd_w: + jal _nmon_outc_a0 + + li a0, ' ' + jal _nmon_outc_a0 + + jal _nmon_gethexw + move s2, s0 + + li a0, ' ' + jal _nmon_outc_a0 + jal _nmon_gethexw + + sw s0, 0(s2) + j nmon_main + +nmon_cmd_g: + jal _nmon_outc_a0 + + li a0, ' ' + jal _nmon_outc_a0 + + jal _nmon_gethexw + move s2, s0 + + nmon_outs msg_nl + + jalr s2 + j nmon_main + +_nmon_outc_a0: + debug_ll_outc_a0 + jr ra + +_nmon_outs: + + lb a0, 0(a1) + addi a1, a1, 1 + beqz a0, _nmon_jr_ra_exit + + debug_ll_outc_a0 + + j _nmon_outs + +_nmon_gethexw: + + li t3, 8 + li t2, 0 + +_get_hex_digit: + debug_ll_getc + + li s1, CODE_ESC + beq s0, s1, nmon_main + + li s1, '0' + bge s0, s1, 0f + j _get_hex_digit + +0: + li s1, '9' + ble s0, s1, 9f + + li s1, 'f' + ble s0, s1, 1f + j _get_hex_digit + +1: + li s1, 'a' + bge s0, s1, 8f + + j _get_hex_digit + +8: /* s0 \in {'a', 'b' ... 'f'} */ + sub a3, s0, s1 + addi a3, a3, 0xa + j 0f + +9: /* s0 \in {'0', '1' ... '9'} */ + li a3, '0' + sub a3, s0, a3 + +0: move a0, s0 + debug_ll_outc_a0 + + sll t2, t2, 4 + or t2, t2, a3 + li t0, 1 + sub t3, t3, t0 + + beqz t3, 0f + + j _get_hex_digit + +0: + move s0, t2 + +_nmon_jr_ra_exit: + jr ra + +msg_prompt: + .asciz "\r\nnmon> " + +msg_nl: + .asciz "\r\n" + +msg_bsp: + .asciz "\b \b" + +#ifdef CONFIG_NMON_HELP +msg_nmon_help: + .ascii "\r\n\r\nnmon commands:\r\n" + .ascii " q - quit\r\n" + .ascii " d <addr> - read 32-bit word from <addr>\r\n" + .ascii " w <addr> <val> - write 32-bit word to <addr>\r\n" + .ascii " g <addr> - jump to <addr>\r\n" + .asciz " use <ESC> key to interrupt current command\r\n" +#endif /* CONFIG_NMON_HELP */ + + .align 2 +nmon_exit: + nmon_outs msg_nl + +#endif /* CONFIG_NMON */ + +.endm + +#endif /* __ASM_RISCV_NMON_H */ |