[RFC 1/1] efi_loader: add dbginfodump.efi

Ilias Apalodimas ilias.apalodimas at linaro.org
Tue Apr 29 10:04:36 CEST 2025


Hello Heinrich

On Mon, 28 Apr 2025 at 11:01, Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
> Provide a test application to dump the EFI_DEBUG_IMAGE_INFO_TABLE
> as implemented in EDK II.
>

I have no objections is adding the efi app. It won't break anything.

> The implementation in EDK II does not match the description in the
> UEFI specification:
>
> In EDK II field EfiDebugImageInfoTable in EFI_DEBUG_IMAGE_INFO_TABLE_HEADER
> is an array of pointers to EFI_DEBUG_IMAGE_INFO structures while the
> specification says "A pointer to the first element of an array of
> EFI_DEBUG_IMAGE_INFO structures."

Hmm where? The definition in EDK2 is

typedef struct {
  volatile UINT32         UpdateStatus;
  UINT32                  TableSize;
  EFI_DEBUG_IMAGE_INFO    *EfiDebugImageInfoTable;
} EFI_DEBUG_IMAGE_INFO_TABLE_HEADER;

So it's still a pointer to the first element and later EDKII treats it
as an array of EFI_DEBUG_IMAGE_INFO elements, which seems to be what
the spec expects.


Cheers
/Ilias

>
> EFI_DEBUG_IMAGE_INFO is not packed in contrast to many other EFI
> structures.
>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
>  lib/efi_loader/Makefile      |   1 +
>  lib/efi_loader/dbginfodump.c | 340 +++++++++++++++++++++++++++++++++++
>  2 files changed, 341 insertions(+)
>  create mode 100644 lib/efi_loader/dbginfodump.c
>
> diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
> index cf050e5385d..0ff068b4307 100644
> --- a/lib/efi_loader/Makefile
> +++ b/lib/efi_loader/Makefile
> @@ -21,6 +21,7 @@ ifeq ($(CONFIG_GENERATE_ACPI_TABLE),)
>  apps-y += dtbdump
>  endif
>  apps-$(CONFIG_BOOTEFI_TESTAPP_COMPILE) += testapp
> +apps-y += dbginfodump
>
>  obj-$(CONFIG_CMD_BOOTEFI_HELLO) += helloworld_efi.o
>  obj-$(CONFIG_EFI_BOOTMGR) += efi_bootmgr.o
> diff --git a/lib/efi_loader/dbginfodump.c b/lib/efi_loader/dbginfodump.c
> new file mode 100644
> index 00000000000..8e6ed637836
> --- /dev/null
> +++ b/lib/efi_loader/dbginfodump.c
> @@ -0,0 +1,340 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2020, Heinrich Schuchardt <xypron.glpk at gmx.de>
> + *
> + * dbginfodump.efi prints out the content of the EFI_DEBUG_IMAGE_INFO_TABLE.
> + * to a file.
> + */
> +
> +#include <efi_api.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 efi_handle_t handle;
> +static struct efi_system_table *systable;
> +static struct efi_boot_services *bs;
> +
> +static efi_guid_t guid_device_path_to_text_protocol =
> +       EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
> +
> +static struct efi_device_path_to_text_protocol *device_path_to_text;
> +
> +/* EFI_DEBUG_IMAGE_INFO_TAB */
> +static const efi_guid_t dbg_info_guid =
> +       EFI_GUID(0x49152E77, 0x1ADA, 0x4764, 0xB7, 0xA2,
> +                0x7A, 0xFE, 0xFE, 0xD9, 0x5E, 0x8B);
> +
> +struct dbg_info {
> +       u32 type;
> +       struct efi_loaded_image *info;
> +       efi_handle_t handle;
> +};
> +
> +struct dbg_info_header {
> +       u32 status;
> +       u32 size;
> +       struct dbg_info **info;
> +};
> +
> +/**
> + * print() - print string
> + *
> + * @string:    text
> + */
> +static void print(u16 *string)
> +{
> +       cout->output_string(cout, string);
> +}
> +
> +/**
> + * error() - print error string
> + *
> + * @string:    error text
> + */
> +static void error(u16 *string)
> +{
> +       cout->set_attribute(cout, EFI_LIGHTRED | EFI_BACKGROUND_BLACK);
> +       print(string);
> +       cout->set_attribute(cout, EFI_LIGHTBLUE | EFI_BACKGROUND_BLACK);
> +}
> +
> +/**
> + * printu() - print unsigned
> + *
> + * @val:       value to print
> + */
> +static void printu(u32 val)
> +{
> +       u16 str[19] = u"0x";
> +       u16 *ptr = &str[2];
> +       u16 ch;
> +
> +       for (ssize_t i = 8 * sizeof(u32) - 4; i >= 0; i -= 4) {
> +               ch = (val >> i & 0xf) + '0';
> +               if (ch > '9')
> +                       ch += 'a' - '9' - 1;
> +               *ptr++ = ch;
> +       }
> +       *ptr = 0;
> +       print(str);
> +}
> +
> +/**
> + * printp() - print pointer
> + *
> + * @p: pointer
> + */
> +static void printp(void *p)
> +{
> +       u16 str[19] = u"0x";
> +       u16 *ptr = &str[2];
> +       u16 ch;
> +
> +       for (ssize_t i = 8 * sizeof(void *) - 4; i >= 0; i -= 4) {
> +               ch = ((uintptr_t)p >> i & 0xf) + '0';
> +               if (ch > '9')
> +                       ch += 'a' - '9' - 1;
> +               *ptr++ = ch;
> +       }
> +       *ptr = 0;
> +       print(str);
> +}
> +
> +/**
> + * 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;
> +}
> +
> +/**
> + * do_help() - print help
> + */
> +static void do_help(void)
> +{
> +       error(u"dump       - print debug info table\r\n");
> +       error(u"exit       - exit the shell\r\n");
> +}
> +
> +/**
> + * get_dbg_info_table() - get debug info table
> + *
> + * Return:     debug info table or NULL
> + */
> +static void *get_dbg_info(void)
> +{
> +       void *dbg = NULL;
> +       efi_uintn_t i;
> +
> +       for (i = 0; i < systable->nr_tables; ++i) {
> +               if (!memcmp(&systable->tables[i].guid, &dbg_info_guid,
> +                           sizeof(efi_guid_t))) {
> +                       dbg = systable->tables[i].table;
> +                       break;
> +               }
> +       }
> +       return dbg;
> +}
> +
> +/**
> + * print_info() - print loaded image protocol
> + */
> +static void print_info(struct efi_loaded_image *info)
> +{
> +       print(u"  Address: [");
> +       printp(info->image_base);
> +       print(u", ");
> +       printp(info->image_base + info->image_size - 1);
> +       print(u"]\r\n");
> +       if (device_path_to_text && info->file_path) {
> +               u16 *string;
> +
> +               string = device_path_to_text->convert_device_path_to_text(
> +                                       info->file_path, true, false);
> +               if (!string) {
> +                       error(u"ConvertDevicePathToText failed");
> +               } else {
> +                       print(u"  File: ");
> +                       print(string);
> +               }
> +               print(u"\r\n");
> +       }
> +}
> +
> +/**
> + * do_dump() - print debug info table
> + */
> +static efi_status_t do_dump(void)
> +{
> +       struct dbg_info_header *dbg;
> +
> +       dbg = get_dbg_info();
> +       if (!dbg) {
> +               error(u"Debug info table not found\r\n");
> +               return EFI_NOT_FOUND;
> +       }
> +       if (dbg->status & 0x01) {
> +               error(u"Update in progress\r\n");
> +               return EFI_LOAD_ERROR;
> +       }
> +       if (dbg->status & 0x02)
> +               print(u"Modified\r\n");
> +       print(u"Number of entries: ");
> +       printu(dbg->size);
> +       print(u"\r\n");
> +
> +       for (u32 i = 0; i < dbg->size; ++i) {
> +               struct dbg_info *info = dbg->info[i];
> +
> +               print(u"Info type ");
> +               printu(info->type);
> +               print(u"\r\n");
> +               if (info->type != 1)
> +                       continue;
> +               print_info(info->info);
> +               print(u"  Handle: ");
> +               printp(info->handle);
> +               print(u"\r\n");
> +       }
> +
> +       return EFI_SUCCESS;
> +}
> +
> +/**
> + * 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)
> +{
> +       efi_status_t ret;
> +
> +       handle = image_handle;
> +       systable = systab;
> +       cerr = systable->std_err;
> +       cout = systable->con_out;
> +       cin = systable->con_in;
> +       bs = systable->boottime;
> +
> +       cout->set_attribute(cout, EFI_LIGHTBLUE | EFI_BACKGROUND_BLACK);
> +       cout->clear_screen(cout);
> +       cout->set_attribute(cout, EFI_WHITE | EFI_BACKGROUND_BLACK);
> +       print(u"Debug Info Table Dump\r\n=====================\r\n\r\n");
> +       cout->set_attribute(cout, EFI_LIGHTBLUE | EFI_BACKGROUND_BLACK);
> +
> +       ret = bs->locate_protocol(&guid_device_path_to_text_protocol,
> +                                 NULL, (void **)&device_path_to_text);
> +       if (ret != EFI_SUCCESS) {
> +               error(u"No device path to text protocol\r\n");
> +               device_path_to_text = NULL;
> +       }
> +
> +       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"dump"))
> +                       do_dump();
> +               else
> +                       do_help();
> +       }
> +
> +       cout->set_attribute(cout, EFI_LIGHTGRAY | EFI_BACKGROUND_BLACK);
> +       cout->clear_screen(cout);
> +       return EFI_SUCCESS;
> +}
> --
> 2.48.1
>


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