An EFI binary dmidump.efi is provided that can be used to check the SMBIOS table for consistency and to dump it as a file.
The tool provides the following commands:
check Check the SMBIOS table for consistency.
exit Leave the tool.
help Show available commands.
save Save the SMBIOS table to a file on the EFI system partition. The file can be further analyzed with the dmidecode command line tool::
dmidecode --from-dump <filename>
Specifying 'nocolor' as load option data suppresses colored output and clearing of the screen.
Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com --- lib/efi_loader/Makefile | 7 + lib/efi_loader/dmidump.c | 596 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 603 insertions(+) create mode 100644 lib/efi_loader/dmidump.c
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile index 24d33d5409..71880d330e 100644 --- a/lib/efi_loader/Makefile +++ b/lib/efi_loader/Makefile @@ -16,6 +16,8 @@ CFLAGS_boothart.o := $(CFLAGS_EFI) -Os -ffreestanding CFLAGS_REMOVE_boothart.o := $(CFLAGS_NON_EFI) CFLAGS_helloworld.o := $(CFLAGS_EFI) -Os -ffreestanding CFLAGS_REMOVE_helloworld.o := $(CFLAGS_NON_EFI) +CFLAGS_dmidump.o := $(CFLAGS_EFI) -Os -ffreestanding +CFLAGS_REMOVE_dmidump.o := $(CFLAGS_NON_EFI) CFLAGS_dtbdump.o := $(CFLAGS_EFI) -Os -ffreestanding CFLAGS_REMOVE_dtbdump.o := $(CFLAGS_NON_EFI) CFLAGS_initrddump.o := $(CFLAGS_EFI) -Os -ffreestanding @@ -31,6 +33,11 @@ always += helloworld.efi targets += helloworld.o endif
+ifneq ($(CONFIG_GENERATE_SMBIOS_TABLE),) +always += dmidump.efi +targets += dmidump.o +endif + ifeq ($(CONFIG_GENERATE_ACPI_TABLE),) always += dtbdump.efi targets += dtbdump.o diff --git a/lib/efi_loader/dmidump.c b/lib/efi_loader/dmidump.c new file mode 100644 index 0000000000..e90d81058c --- /dev/null +++ b/lib/efi_loader/dmidump.c @@ -0,0 +1,596 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2023, Heinrich Schuchardt heinrich.schuchardt@canonical.com + * + * dmidump.efi saves the SMBIOS table as file. + * + * Specifying 'nocolor' as load option data suppresses colored output and + * clearing of the screen. + */ + +#include <efi_api.h> +#include <part.h> +#include <smbios.h> +#include <string.h> + +#define BUFFER_SIZE 64 + +static struct efi_simple_text_output_protocol *cerr; +static struct efi_simple_text_output_protocol *cout; +static struct efi_simple_text_input_protocol *cin; +static struct efi_boot_services *bs; +static efi_handle_t handle; +static struct efi_system_table *systable; +static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID; +static const efi_guid_t smbios3_guid = SMBIOS3_TABLE_GUID; +static const efi_guid_t loaded_image_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID; +static const efi_guid_t guid_simple_file_system_protocol = + EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID; +static const efi_guid_t efi_system_partition_guid = PARTITION_SYSTEM_GUID; +static bool nocolor; + +/** + * color() - set foreground color + * + * @color: foreground color + */ +static void color(u8 color) +{ + if (!nocolor) + cout->set_attribute(cout, color | EFI_BACKGROUND_BLACK); +} + +/** + * print() - print string + * + * @string: text + */ +static void print(u16 *string) +{ + cout->output_string(cout, string); +} + +/** + * cls() - clear screen + */ +static void cls(void) +{ + if (nocolor) + print(u"\r\n"); + else + cout->clear_screen(cout); +} + +/** + * error() - print error string + * + * @string: error text + */ +static void error(u16 *string) +{ + color(EFI_LIGHTRED); + print(string); + color(EFI_LIGHTBLUE); +} + +/** + * efi_input_yn() - get answer to yes/no question + * + * Return: + * y or Y + * EFI_SUCCESS + * n or N + * EFI_ACCESS_DENIED + * ESC + * EFI_ABORTED + */ +static efi_status_t efi_input_yn(void) +{ + struct efi_input_key key = {0}; + efi_uintn_t index; + efi_status_t ret; + + /* Drain the console input */ + ret = cin->reset(cin, true); + for (;;) { + ret = bs->wait_for_event(1, &cin->wait_for_key, &index); + if (ret != EFI_SUCCESS) + continue; + ret = cin->read_key_stroke(cin, &key); + if (ret != EFI_SUCCESS) + continue; + switch (key.scan_code) { + case 0x17: /* Escape */ + return EFI_ABORTED; + default: + break; + } + /* Convert to lower case */ + switch (key.unicode_char | 0x20) { + case 'y': + return EFI_SUCCESS; + case 'n': + return EFI_ACCESS_DENIED; + default: + break; + } + } +} + +/** + * efi_input() - read string from console + * + * @buffer: input buffer + * @buffer_size: buffer size + * Return: status code + */ +static efi_status_t efi_input(u16 *buffer, efi_uintn_t buffer_size) +{ + struct efi_input_key key = {0}; + efi_uintn_t index; + efi_uintn_t pos = 0; + u16 outbuf[2] = u" "; + efi_status_t ret; + + /* Drain the console input */ + ret = cin->reset(cin, true); + *buffer = 0; + for (;;) { + ret = bs->wait_for_event(1, &cin->wait_for_key, &index); + if (ret != EFI_SUCCESS) + continue; + ret = cin->read_key_stroke(cin, &key); + if (ret != EFI_SUCCESS) + continue; + switch (key.scan_code) { + case 0x17: /* Escape */ + print(u"\r\nAborted\r\n"); + return EFI_ABORTED; + default: + break; + } + switch (key.unicode_char) { + case 0x08: /* Backspace */ + if (pos) { + buffer[pos--] = 0; + print(u"\b \b"); + } + break; + case 0x0a: /* Linefeed */ + case 0x0d: /* Carriage return */ + print(u"\r\n"); + return EFI_SUCCESS; + default: + break; + } + /* Ignore surrogate codes */ + if (key.unicode_char >= 0xD800 && key.unicode_char <= 0xDBFF) + continue; + if (key.unicode_char >= 0x20 && + pos < buffer_size - 1) { + *outbuf = key.unicode_char; + buffer[pos++] = key.unicode_char; + buffer[pos] = 0; + print(outbuf); + } + } +} + +/** + * skip_whitespace() - skip over leading whitespace + * + * @pos: UTF-16 string + * Return: pointer to first non-whitespace + */ +static u16 *skip_whitespace(u16 *pos) +{ + for (; *pos && *pos <= 0x20; ++pos) + ; + return pos; +} + +/** + * starts_with() - check if @string starts with @keyword + * + * @string: string to search for keyword + * @keyword: keyword to be searched + * Return: true fi @string starts with the keyword + */ +static bool starts_with(u16 *string, u16 *keyword) +{ + for (; *keyword; ++string, ++keyword) { + if (*string != *keyword) + return false; + } + return true; +} + +/** + * open_file_system() - open simple file system protocol + * + * file_system: interface of the simple file system protocol + * Return: status code + */ +static efi_status_t +open_file_system(struct efi_simple_file_system_protocol **file_system) +{ + struct efi_loaded_image *loaded_image; + efi_status_t ret; + efi_handle_t *handle_buffer = NULL; + efi_uintn_t count; + + ret = bs->open_protocol(handle, &loaded_image_guid, + (void **)&loaded_image, NULL, NULL, + EFI_OPEN_PROTOCOL_GET_PROTOCOL); + if (ret != EFI_SUCCESS) { + error(u"Loaded image protocol not found\r\n"); + return ret; + } + + /* Open the simple file system protocol on the same partition */ + ret = bs->open_protocol(loaded_image->device_handle, + &guid_simple_file_system_protocol, + (void **)file_system, NULL, NULL, + EFI_OPEN_PROTOCOL_GET_PROTOCOL); + if (ret == EFI_SUCCESS) + return ret; + + /* Open the simple file system protocol on the UEFI system partition */ + ret = bs->locate_handle_buffer(BY_PROTOCOL, &efi_system_partition_guid, + NULL, &count, &handle_buffer); + if (ret == EFI_SUCCESS && handle_buffer) + ret = bs->open_protocol(handle_buffer[0], + &guid_simple_file_system_protocol, + (void **)file_system, NULL, NULL, + EFI_OPEN_PROTOCOL_GET_PROTOCOL); + if (ret != EFI_SUCCESS) + error(u"Failed to open simple file system protocol\r\n"); + if (handle) + bs->free_pool(handle_buffer); + + return ret; +} + +/** + * do_help() - print help + */ +static void do_help(void) +{ + error(u"check - check SMBIOS table\r\n"); + error(u"save <file> - save SMBIOS table to file\r\n"); + error(u"exit - exit the shell\r\n"); +} + +/** + * get_config_table() - get configuration table + * + * @guid: GUID of the configuration table + * Return: pointer to configuration table or NULL + */ +static void *get_config_table(const efi_guid_t *guid) +{ + size_t i; + + for (i = 0; i < systable->nr_tables; ++i) { + if (!memcmp(guid, &systable->tables[i].guid, 16)) + return systable->tables[i].table; + } + + return NULL; +} + +/** + * checksum() - calculate checksum + * + * @buf: buffer to checksum + * @len: length of buffer + * Return: checksum + */ +u8 checksum(void *buf, int len) +{ + u8 ret = 0; + + for (u8 *ptr = buf; len; --len, ++ptr) + ret -= *ptr; + + return ret; +} + +/** + * do_check() - check SMBIOS table + * + * Return: status code + */ +efi_status_t do_check(void) +{ + struct smbios3_entry *smbios3_anchor; + void *table, *table_end; + u32 len; + efi_status_t ret; + + smbios3_anchor = get_config_table(&smbios3_guid); + if (smbios3_anchor) { + int r; + + r = memcmp(smbios3_anchor->anchor, "_SM3_", 5); + if (r) { + error(u"Invalid anchor string\n"); + return EFI_LOAD_ERROR; + } + print(u"Found SMBIOS 3 entry point\n"); + if (smbios3_anchor->length != 0x18) { + error(u"Invalid anchor length\n"); + return EFI_LOAD_ERROR; + } + if (checksum(smbios3_anchor, smbios3_anchor->length)) { + error(u"Invalid anchor checksum\n"); + return EFI_LOAD_ERROR; + } + table = (void *)(uintptr_t)smbios3_anchor->struct_table_address; + len = smbios3_anchor->max_struct_size; + } else { + struct smbios_entry *smbios_anchor; + int r; + + smbios_anchor = get_config_table(&smbios_guid); + if (!smbios_anchor) { + error(u"No SMBIOS table\n"); + return EFI_NOT_FOUND; + } + r = memcmp(smbios_anchor->anchor, "_SM_", 4); + if (r) { + error(u"Invalid anchor string\n"); + return EFI_LOAD_ERROR; + } + print(u"Found SMBIOS 2.1 entry point\n"); + if (smbios_anchor->length != 0x1f) { + error(u"Invalid anchor length\n"); + return EFI_LOAD_ERROR; + } + if (checksum(smbios_anchor, smbios_anchor->length)) { + error(u"Invalid anchor checksum\n"); + return EFI_LOAD_ERROR; + } + r = memcmp(smbios_anchor->intermediate_anchor, "_DMI_", 5); + if (ret) { + error(u"Invalid intermediate anchor string\n"); + return EFI_LOAD_ERROR; + } + if (checksum(&smbios_anchor->intermediate_anchor, 0xf)) { + error(u"Invalid intermediate anchor checksum\n"); + return EFI_LOAD_ERROR; + } + table = (void *)(uintptr_t)smbios_anchor->struct_table_address; + len = smbios_anchor->struct_table_length; + } + + table_end = (void *)((u8 *)table + len); + for (struct smbios_header *pos = table; ;) { + u8 *str = (u8 *)pos + pos->length; + + if (!*str) + ++str; + while (*str) { + for (; *str; ++str) { + if ((void *)str >= table_end) { + error(u"Structure table length exceeded\n"); + return EFI_LOAD_ERROR; + } + } + ++str; + } + ++str; + if ((void *)str > table_end) { + error(u"Structure table length exceeded\n"); + return EFI_LOAD_ERROR; + } + if (pos->type == 0x7f) /* End of table */ + break; + pos = (struct smbios_header *)str; + } + + return EFI_SUCCESS; +} + +/** + * do_save() - save SMBIOS table + * + * @filename: file name + * Return: status code + */ +static efi_status_t do_save(u16 *filename) +{ + struct smbios3_entry *smbios3_anchor; + u8 *buf; + struct efi_simple_file_system_protocol *file_system; + efi_uintn_t size; + struct efi_file_handle *root, *file; + efi_uintn_t ret; + + ret = do_check(); + if (ret != EFI_SUCCESS) + return ret; + + smbios3_anchor = get_config_table(&smbios3_guid); + if (smbios3_anchor) { + size = 0x20 + smbios3_anchor->max_struct_size; + ret = bs->allocate_pool(EFI_LOADER_DATA, size, (void **)&buf); + if (ret != EFI_SUCCESS) { + error(u"Out of memory\n"); + return ret; + } + + memset(buf, 0, size); + memcpy(buf, smbios3_anchor, smbios3_anchor->length); + memcpy(buf + 0x20, + (void *)(uintptr_t)smbios3_anchor->struct_table_address, + smbios3_anchor->max_struct_size); + + smbios3_anchor = (struct smbios3_entry *)buf; + smbios3_anchor->struct_table_address = 0x20; + smbios3_anchor->checksum += + checksum(smbios3_anchor, smbios3_anchor->length); + } else { + struct smbios_entry *smbios_anchor; + + smbios_anchor = get_config_table(&smbios_guid); + if (!smbios_anchor) { + /* Should not be reached after successful do_check() */ + error(u"No SMBIOS table\n"); + return EFI_NOT_FOUND; + } + + size = 0x20 + smbios_anchor->struct_table_length; + + ret = bs->allocate_pool(EFI_LOADER_DATA, size, (void **)&buf); + if (ret != EFI_SUCCESS) { + error(u"Out of memory\n"); + return ret; + } + + memset(buf, 0, size); + memcpy(buf, smbios_anchor, smbios_anchor->length); + memcpy(buf + 0x20, + (void *)(uintptr_t)smbios_anchor->struct_table_address, + smbios_anchor->struct_table_length); + + smbios_anchor = (struct smbios_entry *)buf; + smbios_anchor->struct_table_address = 0x20; + smbios_anchor->intermediate_checksum += + checksum(&smbios_anchor->intermediate_anchor, 0xf); + smbios_anchor->checksum += + checksum(smbios_anchor, smbios_anchor->length); + } + + filename = skip_whitespace(filename); + + ret = open_file_system(&file_system); + if (ret != EFI_SUCCESS) + return ret; + + /* Open volume */ + ret = file_system->open_volume(file_system, &root); + if (ret != EFI_SUCCESS) { + error(u"Failed to open volume\r\n"); + return ret; + } + /* Check if file already exists */ + ret = root->open(root, &file, filename, EFI_FILE_MODE_READ, 0); + if (ret == EFI_SUCCESS) { + file->close(file); + print(u"Overwrite existing file (y/n)? "); + ret = efi_input_yn(); + print(u"\r\n"); + if (ret != EFI_SUCCESS) { + root->close(root); + error(u"Aborted by user\r\n"); + bs->free_pool(buf); + return ret; + } + } + + /* Create file */ + ret = root->open(root, &file, filename, + EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE | + EFI_FILE_MODE_CREATE, EFI_FILE_ARCHIVE); + if (ret == EFI_SUCCESS) { + /* Write file */ + ret = file->write(file, &size, buf); + if (ret != EFI_SUCCESS) + error(u"Failed to write file\r\n"); + file->close(file); + } else { + error(u"Failed to open file\r\n"); + } + root->close(root); + + if (ret == EFI_SUCCESS) { + print(filename); + print(u" written\r\n"); + } + + bs->free_pool(buf); + + return ret; +} + +/** + * get_load_options() - get load options + * + * Return: load options or NULL + */ +static u16 *get_load_options(void) +{ + efi_status_t ret; + struct efi_loaded_image *loaded_image; + + ret = bs->open_protocol(handle, &loaded_image_guid, + (void **)&loaded_image, NULL, NULL, + EFI_OPEN_PROTOCOL_GET_PROTOCOL); + if (ret != EFI_SUCCESS) { + error(u"Loaded image protocol not found\r\n"); + return NULL; + } + + if (!loaded_image->load_options_size || !loaded_image->load_options) + return NULL; + + return loaded_image->load_options; +} + +/** + * efi_main() - entry point of the EFI application. + * + * @handle: handle of the loaded image + * @systab: system table + * Return: status code + */ +efi_status_t EFIAPI efi_main(efi_handle_t image_handle, + struct efi_system_table *systab) +{ + u16 *load_options; + + handle = image_handle; + systable = systab; + cerr = systable->std_err; + cout = systable->con_out; + cin = systable->con_in; + bs = systable->boottime; + load_options = get_load_options(); + + if (starts_with(load_options, u"nocolor")) + nocolor = true; + + color(EFI_WHITE); + cls(); + print(u"DMI Dump\r\n========\r\n\r\n"); + color(EFI_LIGHTBLUE); + + for (;;) { + u16 command[BUFFER_SIZE]; + u16 *pos; + efi_uintn_t ret; + + print(u"=> "); + ret = efi_input(command, sizeof(command)); + if (ret == EFI_ABORTED) + break; + pos = skip_whitespace(command); + if (starts_with(pos, u"exit")) { + break; + } else if (starts_with(pos, u"check")) { + ret = do_check(); + if (ret == EFI_SUCCESS) + print(u"OK\n"); + } else if (starts_with(pos, u"save ")) { + do_save(pos + 5); + } else { + do_help(); + } + } + + color(EFI_LIGHTGRAY); + cls(); + + return EFI_SUCCESS; +}