cmd/exception: test RISC-V 16 bit aligned instruction

A 16 bit aligned instruction should generated an exception if the C
extension is not available.

Provide an 'extension ialign16' command for testing exception handling.

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 ialign16
    Unhandled exception: Instruction address misaligned
    EPC: 0000000087719138 RA: 0000000087719218 TVAL: 000000008771913e
    EPC: 0000000080020138 RA: 0000000080020218 reloc adjusted

    Code: 0113 0101 8067 0000 0113 ff01 3423 0011 (006f 0060)

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
This commit is contained in:
Heinrich Schuchardt 2023-09-21 12:39:29 +02:00 committed by Leo Yu-Chi Liang
parent f2e4b9d3c2
commit ef5ccaae64

View file

@ -24,6 +24,19 @@ static int do_ebreak(struct cmd_tbl *cmdtp, int flag, int argc,
return CMD_RET_FAILURE;
}
static int do_ialign16(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
asm volatile (
/* jump skipping 2 bytes */
".long 0x0060006f\n"
".long 0x006f0000\n"
".long 0x00000060\n"
);
printf("The system supports 16 bit aligned instructions.\n");
return CMD_RET_SUCCESS;
}
static int do_unaligned(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
@ -48,6 +61,8 @@ static struct cmd_tbl cmd_sub[] = {
"", ""),
U_BOOT_CMD_MKENT(ebreak, CONFIG_SYS_MAXARGS, 1, do_ebreak,
"", ""),
U_BOOT_CMD_MKENT(ialign16, CONFIG_SYS_MAXARGS, 1, do_ialign16,
"", ""),
U_BOOT_CMD_MKENT(unaligned, CONFIG_SYS_MAXARGS, 1, do_unaligned,
"", ""),
U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
@ -59,6 +74,7 @@ static char exception_help_text[] =
" The following exceptions are available:\n"
" compressed - compressed instruction\n"
" ebreak - breakpoint\n"
" ialign16 - 16 bit aligned instruction\n"
" undefined - illegal instruction\n"
" unaligned - load address misaligned\n"
;