diff options
| author | Heinrich Schuchardt | 2023-09-21 10:42:18 +0200 |
|---|---|---|
| committer | Leo Yu-Chi Liang | 2023-10-04 17:59:40 +0800 |
| commit | f2e4b9d3c2f858f5ce7e317b2974d74353abb2a2 (patch) | |
| tree | c52e0285aaaaa5269293655a77939a8a068cf1e4 | |
| parent | c202426d6ac6bffccf19e958dc176f7d29d0528e (diff) | |
cmd/exception: support RISC-V compressed instruction
Eliminating the C extension on application processors is under
discussion.
Support emitting a compressed instruction. This will lead to an
illegal instruction exception if the C extension is not implemented.
For testing build qemu-riscv64_defconfig with CONFIG_RISCV_ISA_C=n
and run with
qemu-system-riscv64 -M virt -bios u-boot -nographic -cpu rv64,c=false
=> exception compressed
Unhandled exception: Illegal instruction
EPC: 0000000087731708 RA: 000000008773fe44 TVAL: 0000000000004501
EPC: 000000008001b708 RA: 0000000080029e44 reloc adjusted
Code: 0b93 0000 0493 0000 0993 0000 f06f ccdf (4501)
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
| -rw-r--r-- | cmd/riscv/exception.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/cmd/riscv/exception.c b/cmd/riscv/exception.c index 7a08061d120..db8d8af0483 100644 --- a/cmd/riscv/exception.c +++ b/cmd/riscv/exception.c @@ -8,6 +8,15 @@ #include <common.h> #include <command.h> +static int do_compressed(struct cmd_tbl *cmdtp, int flag, int argc, + char *const argv[]) +{ + /* c.li a0, 0; c.li a0, 0 */ + asm volatile (".long 0x45014501\n"); + printf("The system supports compressed instructions.\n"); + return CMD_RET_SUCCESS; +} + static int do_ebreak(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) { @@ -35,6 +44,8 @@ static int do_undefined(struct cmd_tbl *cmdtp, int flag, int argc, } static struct cmd_tbl cmd_sub[] = { + U_BOOT_CMD_MKENT(compressed, CONFIG_SYS_MAXARGS, 1, do_compressed, + "", ""), U_BOOT_CMD_MKENT(ebreak, CONFIG_SYS_MAXARGS, 1, do_ebreak, "", ""), U_BOOT_CMD_MKENT(unaligned, CONFIG_SYS_MAXARGS, 1, do_unaligned, @@ -46,9 +57,10 @@ static struct cmd_tbl cmd_sub[] = { static char exception_help_text[] = "<ex>\n" " The following exceptions are available:\n" - " ebreak - breakpoint\n" - " undefined - illegal instruction\n" - " unaligned - load address misaligned\n" + " compressed - compressed instruction\n" + " ebreak - breakpoint\n" + " undefined - illegal instruction\n" + " unaligned - load address misaligned\n" ; #include <exception.h> |