Some versions of KVM don't allow access to the cycle CSR.
Provide a command 'exception rdcycle' for testing.
If the cycle CSR is accessible, we get an output like:
=> exception rdcycle
cycle = 0x41f7563de
If the cycle CSR is not accessible, we get an output like:
=> exception rdcycle
Unhandled exception: Illegal instruction
Put subcommands into alphabetical order in long help.
Signed-off-by: Heinrich Schuchardt <[email protected]>
---
cmd/riscv/exception.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/cmd/riscv/exception.c b/cmd/riscv/exception.c
index 2b58b1c449c..16e335327f1 100644
--- a/cmd/riscv/exception.c
+++ b/cmd/riscv/exception.c
@@ -36,6 +36,14 @@ static int do_ialign16(struct cmd_tbl *cmdtp, int flag, int
argc,
return CMD_RET_SUCCESS;
}
+static int do_rdcycle(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ printf("cycle = 0x%lx\n", csr_read(CSR_CYCLE));
+
+ return CMD_RET_SUCCESS;
+}
+
static int do_unaligned(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
@@ -62,6 +70,8 @@ static struct cmd_tbl cmd_sub[] = {
"", ""),
U_BOOT_CMD_MKENT(ialign16, CONFIG_SYS_MAXARGS, 1, do_ialign16,
"", ""),
+ U_BOOT_CMD_MKENT(rdcycle, CONFIG_SYS_MAXARGS, 1, do_rdcycle,
+ "", ""),
U_BOOT_CMD_MKENT(unaligned, CONFIG_SYS_MAXARGS, 1, do_unaligned,
"", ""),
U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
@@ -74,7 +84,8 @@ U_BOOT_LONGHELP(exception,
" compressed - compressed instruction\n"
" ebreak - breakpoint\n"
" ialign16 - 16 bit aligned instruction\n"
- " undefined - illegal instruction\n"
- " unaligned - load address misaligned\n");
+ " rdcycle - read cycle CSR\n"
+ " unaligned - load address misaligned\n"
+ " undefined - illegal instruction\n");
#include <exception.h>
--
2.45.2
