cmd: add exception command

The 'exception' command allows to test exception handling.

This implementation supports ARM, x86, RISC-V and the following exceptions:
* 'breakpoint' - prefetch abort exception (ARM 32bit only)
* 'unaligned'  - data abort exception (ARM only)
* 'undefined'  - undefined instruction exception

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This commit is contained in:
Heinrich Schuchardt 2018-12-26 17:20:35 +01:00 committed by Tom Rini
parent c986aa624b
commit dab8788a8c
11 changed files with 232 additions and 0 deletions

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@ -86,6 +86,7 @@ M: Albert Aribaud <albert.u.boot@aribaud.net>
S: Maintained
T: git git://git.denx.de/u-boot-arm.git
F: arch/arm/
F: cmd/arm/
ARM ALTERA SOCFPGA
M: Marek Vasut <marex@denx.de>
@ -677,6 +678,7 @@ M: Rick Chen <rick@andestech.com>
S: Maintained
T: git git://git.denx.de/u-boot-riscv.git
F: arch/riscv/
F: cmd/riscv/
F: tools/prelink-riscv.c
ROCKUSB
@ -788,6 +790,7 @@ M: Bin Meng <bmeng.cn@gmail.com>
S: Maintained
T: git git://git.denx.de/u-boot-x86.git
F: arch/x86/
F: cmd/x86/
XTENSA
M: Max Filippov <jcmvbkbc@gmail.com>

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@ -1433,6 +1433,12 @@ config CMD_EFIDEBUG
particularly for managing boot parameters as well as examining
various EFI status for debugging.
config CMD_EXCEPTION
bool "exception - raise exception"
depends on ARM || RISCV || X86
help
Enable the 'exception' command which allows to raise an exception.
config CMD_LED
bool "led"
depends on LED

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@ -173,6 +173,8 @@ obj-$(CONFIG_CMD_BLOB) += blob.o
# Android Verified Boot 2.0
obj-$(CONFIG_CMD_AVB) += avb.o
obj-$(CONFIG_ARM) += arm/
obj-$(CONFIG_RISCV) += riscv/
obj-$(CONFIG_X86) += x86/
obj-$(CONFIG_ARCH_MVEBU) += mvebu/

7
cmd/arm/Makefile Normal file
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@ -0,0 +1,7 @@
# SPDX-License-Identifier: GPL-2.0+
ifdef CONFIG_ARM64
obj-$(CONFIG_CMD_EXCEPTION) += exception64.o
else
obj-$(CONFIG_CMD_EXCEPTION) += exception.o
endif

61
cmd/arm/exception.c Normal file
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@ -0,0 +1,61 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* The 'exception' command can be used for testing exception handling.
*
* Copyright (c) 2018, Heinrich Schuchardt <xypron.glpk@gmx.de>
*/
#include <common.h>
#include <command.h>
static int do_unaligned(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
/*
* The LDRD instruction requires the data source to be four byte aligned
* even if strict alignment fault checking is disabled in the system
* control register.
*/
asm volatile (
"MOV r5, sp\n"
"ADD r5, #1\n"
"LDRD r6, r7, [r5]\n");
return CMD_RET_FAILURE;
}
static int do_breakpoint(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
asm volatile ("BKPT #123\n");
return CMD_RET_FAILURE;
}
static int do_undefined(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
/*
* 0xe7f...f. is undefined in ARM mode
* 0xde.. is undefined in Thumb mode
*/
asm volatile (".word 0xe7f7defb\n");
return CMD_RET_FAILURE;
}
static cmd_tbl_t cmd_sub[] = {
U_BOOT_CMD_MKENT(breakpoint, CONFIG_SYS_MAXARGS, 1, do_breakpoint,
"", ""),
U_BOOT_CMD_MKENT(unaligned, CONFIG_SYS_MAXARGS, 1, do_unaligned,
"", ""),
U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
"", ""),
};
static char exception_help_text[] =
"<ex>\n"
" The following exceptions are available:\n"
" breakpoint - prefetch abort\n"
" unaligned - data abort\n"
" undefined - undefined instruction\n"
;
#include <exception.h>

33
cmd/arm/exception64.c Normal file
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@ -0,0 +1,33 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* The 'exception' command can be used for testing exception handling.
*
* Copyright (c) 2018, Heinrich Schuchardt <xypron.glpk@gmx.de>
*/
#include <common.h>
#include <command.h>
static int do_undefined(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
/*
* 0xe7f...f. is undefined in ARM mode
* 0xde.. is undefined in Thumb mode
*/
asm volatile (".word 0xe7f7defb\n");
return CMD_RET_FAILURE;
}
static cmd_tbl_t cmd_sub[] = {
U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
"", ""),
};
static char exception_help_text[] =
"<ex>\n"
" The following exceptions are available:\n"
" undefined - undefined instruction\n"
;
#include <exception.h>

3
cmd/riscv/Makefile Normal file
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@ -0,0 +1,3 @@
# SPDX-License-Identifier: GPL-2.0+
obj-$(CONFIG_CMD_EXCEPTION) += exception.o

29
cmd/riscv/exception.c Normal file
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@ -0,0 +1,29 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* The 'exception' command can be used for testing exception handling.
*
* Copyright (c) 2018, Heinrich Schuchardt <xypron.glpk@gmx.de>
*/
#include <common.h>
#include <command.h>
static int do_undefined(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
asm volatile (".word 0xffffffff\n");
return CMD_RET_FAILURE;
}
static cmd_tbl_t cmd_sub[] = {
U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
"", ""),
};
static char exception_help_text[] =
"<ex>\n"
" The following exceptions are available:\n"
" undefined - undefined instruction\n"
;
#include <exception.h>

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@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0+
obj-y += mtrr.o
obj-$(CONFIG_CMD_EXCEPTION) += exception.o
obj-$(CONFIG_HAVE_FSP) += fsp.o

29
cmd/x86/exception.c Normal file
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@ -0,0 +1,29 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* The 'exception' command can be used for testing exception handling.
*
* Copyright (c) 2018, Heinrich Schuchardt <xypron.glpk@gmx.de>
*/
#include <common.h>
#include <command.h>
static int do_undefined(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
asm volatile (".word 0xffff\n");
return CMD_RET_FAILURE;
}
static cmd_tbl_t cmd_sub[] = {
U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
"", ""),
};
static char exception_help_text[] =
"<ex>\n"
" The following exceptions are available:\n"
" undefined - undefined instruction\n"
;
#include <exception.h>

58
include/exception.h Normal file
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@ -0,0 +1,58 @@
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* The 'exception' command can be used for testing exception handling.
*
* Copyright (c) 2018, Heinrich Schuchardt <xypron.glpk@gmx.de>
*/
static int do_exception(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
cmd_tbl_t *cp;
if (argc != 2)
return CMD_RET_USAGE;
/* drop sub-command parameter */
argc--;
argv++;
cp = find_cmd_tbl(argv[0], cmd_sub, ARRAY_SIZE(cmd_sub));
if (cp)
return cp->cmd(cmdtp, flag, argc, argv);
return CMD_RET_USAGE;
}
static int exception_complete(int argc, char * const argv[], char last_char,
int maxv, char *cmdv[])
{
int len = 0;
int i = 0;
cmd_tbl_t *cmdtp;
switch (argc) {
case 1:
break;
case 2:
len = strlen(argv[1]);
break;
default:
return 0;
}
for (cmdtp = cmd_sub; cmdtp != cmd_sub + ARRAY_SIZE(cmd_sub); cmdtp++) {
if (i >= maxv - 1)
return i;
if (!strncmp(argv[1], cmdtp->name, len))
cmdv[i++] = cmdtp->name;
}
cmdv[i] = NULL;
return i;
}
U_BOOT_CMD_COMPLETE(
exception, 2, 0, do_exception,
"Forces an exception to occur",
exception_help_text, exception_complete
);