diff options
Diffstat (limited to 'cmd/arm')
| -rw-r--r-- | cmd/arm/Makefile | 7 | ||||
| -rw-r--r-- | cmd/arm/exception.c | 59 | ||||
| -rw-r--r-- | cmd/arm/exception64.c | 87 |
3 files changed, 153 insertions, 0 deletions
diff --git a/cmd/arm/Makefile b/cmd/arm/Makefile new file mode 100644 index 00000000000..94367dcb459 --- /dev/null +++ b/cmd/arm/Makefile @@ -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 diff --git a/cmd/arm/exception.c b/cmd/arm/exception.c new file mode 100644 index 00000000000..8857f121604 --- /dev/null +++ b/cmd/arm/exception.c @@ -0,0 +1,59 @@ +// 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 <command.h> + +static int do_unaligned(struct cmd_tbl *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(struct cmd_tbl *cmdtp, int flag, int argc, + char *const argv[]) +{ + asm volatile ("BKPT #123\n"); + return CMD_RET_FAILURE; +} + +static int do_undefined(struct cmd_tbl *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 struct cmd_tbl 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, + "", ""), +}; + +U_BOOT_LONGHELP(exception, + "<ex>\n" + " The following exceptions are available:\n" + " breakpoint - prefetch abort\n" + " unaligned - data abort\n" + " undefined - undefined instruction\n"); + +#include <exception.h> diff --git a/cmd/arm/exception64.c b/cmd/arm/exception64.c new file mode 100644 index 00000000000..4c5b953168c --- /dev/null +++ b/cmd/arm/exception64.c @@ -0,0 +1,87 @@ +// 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 <command.h> +#include <linux/bitops.h> + +static int do_undefined(struct cmd_tbl *cmdtp, int flag, int argc, + char *const argv[]) +{ + /* + * Instructions starting with the upper 16 bits all 0 are permanently + * undefined. The lower 16 bits can be used for some kind of immediate. + * --- ARMv8 ARM (ARM DDI 0487G.a C6.2.339: "UDF") + */ + asm volatile (".word 0x00001234\n"); + + return CMD_RET_FAILURE; +} + +/* + * The ID_AA64MMFR2_EL1 register name is only know to binutils for ARMv8.2 + * and later architecture revisions. However the register is valid regardless + * of binutils architecture support or the core the code is running on, so + * just use the generic encoding. + */ +#define ID_AA64MMFR2_EL1 "S3_0_C0_C7_2" + +static int do_unaligned(struct cmd_tbl *cmdtp, int flag, int argc, + char *const argv[]) +{ + uint64_t reg; + + /* + * The unaligned LDAR access below is only guaranteed to generate an + * alignment fault on cores not implementing FEAT_LSE2. To avoid false + * negatives, check this condition before we exectute LDAR. + */ + asm ("mrs %0, "ID_AA64MMFR2_EL1"\n" : "=r" (reg)); + if (reg & GENMASK(35, 32)) { + printf("unaligned access check only supported on pre-v8.4 cores\n"); + return CMD_RET_FAILURE; + } + + /* + * The load acquire instruction requires the data source to be + * naturally aligned, and will fault even if strict alignment fault + * checking is disabled (but only without FEAT_LSE2). + * --- ARMv8 ARM (ARM DDI 0487G.a B2.5.2: "Alignment of data accesses") + */ + asm volatile ( + "mov x1, sp\n\t" + "orr x1, x1, #3\n\t" + "ldar x0, [x1]\n" + ::: "x0", "x1" ); + + return CMD_RET_FAILURE; +} + +static int do_breakpoint(struct cmd_tbl *cmdtp, int flag, int argc, + char *const argv[]) +{ + asm volatile ("brk #123\n"); + + return CMD_RET_FAILURE; +} + +static struct cmd_tbl 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, + "", ""), +}; + +U_BOOT_LONGHELP(exception, + "<ex>\n" + " The following exceptions are available:\n" + " breakpoint - breakpoint instruction exception\n" + " unaligned - unaligned LDAR data abort\n" + " undefined - undefined instruction exception\n"); + +#include <exception.h> |