Re: [PATCH v3 2/2] efi_loader: provide tool to dump SMBIOS table

On Wed, 3 Jan 2024 at 10:07, Heinrich Schuchardt heinrich.schuchardt@canonical.com wrote:

An EFI binary smbiosdump.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

v3: rename the tool restructure the code handle NULL value in starts_with() v2: fix an incorrect variable usage when checking the result of memcmp

---

lib/efi_loader/Makefile | 7 + lib/efi_loader/smbiosdump.c | 622 ++++++++++++++++++++++++++++++++++++ 2 files changed, 629 insertions(+) create mode 100644 lib/efi_loader/smbiosdump.c

diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile index 24d33d5409..25060bbd95 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_smbiosdump.o := $(CFLAGS_EFI) -Os -ffreestanding +CFLAGS_REMOVE_smbiosdump.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 += smbiosdump.efi +targets += smbiosdump.o +endif

ifeq ($(CONFIG_GENERATE_ACPI_TABLE),) always += dtbdump.efi targets += dtbdump.o diff --git a/lib/efi_loader/smbiosdump.c b/lib/efi_loader/smbiosdump.c new file mode 100644 index 0000000000..8a42794789 --- /dev/null +++ b/lib/efi_loader/smbiosdump.c @@ -0,0 +1,622 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*

• • Copyright 2023, Heinrich Schuchardt heinrich.schuchardt@canonical.com
• • smbiosdump.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) +{

•   if (!string || !keyword)
  

•           return NULL;
  

•   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;
  

•   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 (r) {
  

•                   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;
  

+}

+/**

• • save_file() - save file to EFI system partition
• • @filename: file name
• • @buf: buffer to write
• • @size: size of the buffer
• */

+efi_status_t save_file(u16 *filename, void *buf, efi_uintn_t size) +{

•   efi_uintn_t ret;
  

•   struct efi_simple_file_system_protocol *file_system;
  

•   struct efi_file_handle *root, *file;
  

•   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);
  

•   return ret;
  

+}

+/**

• • 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;
  

•   efi_uintn_t size;
  

•   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 = save_file(filename, buf, size);
  

•   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;
  

+}

+/**

• • command_loop - process user commands
• */

+static void command_loop(void) +{

•   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();
  

•           }
  

•   }
  

+}

+/**

• • 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);
  

•   command_loop();
  

•   color(EFI_LIGHTGRAY);
  

•   cls();
  

•   return EFI_SUCCESS;
  

+}

2.43.0

Acked-by: Ilias Apalodimas ilias.apalodimas@linaro.org