[PATCH v2] cmd: exception: unaligned data access on RISC-V
Heinrich Schuchardt
xypron.glpk at gmx.de
Thu Aug 6 12:34:59 CEST 2020
The command 'exception' can be used to test the handling of exceptions.
Currently the exception command only allows to create an illegal
instruction exception on RISC-V.
Provide a sub-command 'exception unaligned' to cause a misaligned load
address exception.
Adjust the online help for 'exception undefined'.
Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
v2:
If unaligned access is support, print success message.
---
cmd/riscv/exception.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/cmd/riscv/exception.c b/cmd/riscv/exception.c
index 3c8dbbec0e..9687cec812 100644
--- a/cmd/riscv/exception.c
+++ b/cmd/riscv/exception.c
@@ -8,6 +8,18 @@
#include <common.h>
#include <command.h>
+static int do_unaligned(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ asm volatile (
+ "auipc a1, 0\n"
+ "ori a1, a1, 3\n"
+ "lw a2, (0)(a1)\n"
+ );
+ printf("The system supports unaligned access.\n");
+ return CMD_RET_SUCCESS;
+}
+
static int do_undefined(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
@@ -16,6 +28,8 @@ static int do_undefined(struct cmd_tbl *cmdtp, int flag, int argc,
}
static struct cmd_tbl cmd_sub[] = {
+ U_BOOT_CMD_MKENT(unaligned, CONFIG_SYS_MAXARGS, 1, do_unaligned,
+ "", ""),
U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
"", ""),
};
@@ -23,7 +37,8 @@ static struct cmd_tbl cmd_sub[] = {
static char exception_help_text[] =
"<ex>\n"
" The following exceptions are available:\n"
- " undefined - undefined instruction\n"
+ " undefined - illegal instruction\n"
+ " unaligned - load address misaligned\n"
;
#include <exception.h>
--
2.27.0
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