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| author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2023-05-22 07:28:35 +0200 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2023-05-23 09:26:09 +0200 |
| commit | 89db65620d09222ce5c4f5076a50ac663cad9293 (patch) | |
| tree | 6e28d2d5a71e762a6a7bd489f76ccbaa5a2a2b2c /arch/arm/cpu | |
| parent | 8230298513eaec705b44acba0ff0d9626eabd0b3 (diff) | |
| download | barebox-89db65620d09222ce5c4f5076a50ac663cad9293.tar.gz barebox-89db65620d09222ce5c4f5076a50ac663cad9293.tar.xz | |
ARM: mmuinfo: add options for enabling/disabling zero page trapping
mmuinfo 0 will most likely trigger a translation fault. To allow
decoding the zero page or to allow reading BootROM code at address 0,
teach mmuinfo -z to disable trapping of the zero page and mmuinfo -Z to
reinstate the faulting zero page.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20230522052835.1039143-12-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'arch/arm/cpu')
| -rw-r--r-- | arch/arm/cpu/mmuinfo.c | 47 |
1 files changed, 45 insertions, 2 deletions
diff --git a/arch/arm/cpu/mmuinfo.c b/arch/arm/cpu/mmuinfo.c index 413f2f337e..44d6980a75 100644 --- a/arch/arm/cpu/mmuinfo.c +++ b/arch/arm/cpu/mmuinfo.c @@ -6,8 +6,10 @@ #include <common.h> #include <command.h> +#include <getopt.h> #include <asm/mmuinfo.h> #include <asm/system_info.h> +#include <zero_page.h> #include <mmu.h> int mmuinfo(void *addr) @@ -23,8 +25,40 @@ int mmuinfo(void *addr) static __maybe_unused int do_mmuinfo(int argc, char *argv[]) { unsigned long addr; + int access_zero_page = -1; + int opt; - if (argc < 2) + while ((opt = getopt(argc, argv, "zZ")) > 0) { + switch (opt) { + case 'z': + access_zero_page = true; + break; + case 'Z': + access_zero_page = false; + break; + default: + return COMMAND_ERROR_USAGE; + } + } + + if (access_zero_page >= 0) { + if (argc - optind != 0) + return COMMAND_ERROR_USAGE; + + if (!zero_page_remappable()) { + pr_warn("No architecture support for zero page remap\n"); + return -ENOSYS; + } + + if (access_zero_page) + zero_page_access(); + else + zero_page_faulting(); + + return 0; + } + + if (argc - optind != 1) return COMMAND_ERROR_USAGE; addr = strtoul_suffix(argv[1], NULL, 0); @@ -32,11 +66,20 @@ static __maybe_unused int do_mmuinfo(int argc, char *argv[]) return mmuinfo((void *)addr); } +BAREBOX_CMD_HELP_START(mmuinfo) +BAREBOX_CMD_HELP_TEXT("Show MMU/cache information using the cp15/model-specific registers.") +BAREBOX_CMD_HELP_TEXT("") +BAREBOX_CMD_HELP_TEXT("Options:") +BAREBOX_CMD_HELP_OPT ("-z", "enable access to zero page") +BAREBOX_CMD_HELP_OPT ("-Z", "disable access to zero page") +BAREBOX_CMD_HELP_END + #ifdef CONFIG_COMMAND_SUPPORT BAREBOX_CMD_START(mmuinfo) .cmd = do_mmuinfo, BAREBOX_CMD_DESC("show MMU/cache information of an address") - BAREBOX_CMD_OPTS("ADDRESS") + BAREBOX_CMD_OPTS("[-zZ | ADDRESS]") BAREBOX_CMD_GROUP(CMD_GRP_INFO) + BAREBOX_CMD_HELP(cmd_mmuinfo_help) BAREBOX_CMD_END #endif |