--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
+ *
+ * initrddump.efi saves the initial RAM disk provided via the
+ * EFI_LOAD_FILE2_PROTOCOL.
+ */
+
+#include <common.h>
+#include <efi_api.h>
+#include <efi_load_initrd.h>
+
+#define BUFFER_SIZE 64
+#define ESC 0x17
+
+#define efi_size_in_pages(size) (((size) + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT)
+
+static struct efi_system_table *systable;
+static struct efi_boot_services *bs;
+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 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 load_file2_guid = EFI_LOAD_FILE2_PROTOCOL_GUID;
+static efi_handle_t handle;
+
+/*
+ * Device path defined by Linux to identify the handle providing the
+ * EFI_LOAD_FILE2_PROTOCOL used for loading the initial ramdisk.
+ */
+static const struct efi_initrd_dp initrd_dp = {
+ .vendor = {
+ {
+ DEVICE_PATH_TYPE_MEDIA_DEVICE,
+ DEVICE_PATH_SUB_TYPE_VENDOR_PATH,
+ sizeof(initrd_dp.vendor),
+ },
+ EFI_INITRD_MEDIA_GUID,
+ },
+ .end = {
+ DEVICE_PATH_TYPE_END,
+ DEVICE_PATH_SUB_TYPE_END,
+ sizeof(initrd_dp.end),
+ }
+};
+
+/**
+ * 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);
+}
+
+/*
+ * printx() - print hexadecimal number
+ *
+ * @val: value to print;
+ * @prec: minimum number of digits to print
+ */
+static void printx(u64 val, u32 prec)
+{
+ int i;
+ u16 c;
+ u16 buf[16];
+ u16 *pos = buf;
+
+ for (i = 2 * sizeof(val) - 1; i >= 0; --i) {
+ c = (val >> (4 * i)) & 0x0f;
+ if (c || pos != buf || !i || i < prec) {
+ c += '0';
+ if (c > '9')
+ c += 'a' - '9' - 1;
+ *pos++ = c;
+ }
+ }
+ *pos = 0;
+ print(buf);
+}
+
+/**
+ * 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] = L" ";
+ 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(L"\r\nAborted\r\n");
+ return EFI_ABORTED;
+ default:
+ break;
+ }
+ switch (key.unicode_char) {
+ case 0x08: /* Backspace */
+ if (pos) {
+ buffer[pos--] = 0;
+ print(L"\b \b");
+ }
+ break;
+ case 0x0a: /* Linefeed */
+ case 0x0d: /* Carriage return */
+ print(L"\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(L"load - show length and CRC32 of initial RAM disk\r\n");
+ error(L"save <initrd> - save initial RAM disk to file\r\n");
+ error(L"exit - exit the shell\r\n");
+}
+
+/**
+ * get_initrd() - read initial RAM disk via EFI_LOAD_FILE2_PROTOCOL
+ *
+ * @initrd: on return buffer with initial RAM disk
+ * @initrd_size: size of initial RAM disk
+ * Return: status code
+ */
+static efi_status_t get_initrd(void **initrd, efi_uintn_t *initrd_size)
+{
+ struct efi_device_path *dp = (struct efi_device_path *)&initrd_dp;
+ struct efi_load_file_protocol *load_file2_prot;
+ u64 buffer;
+ efi_handle_t handle;
+ efi_status_t ret;
+
+ *initrd = NULL;
+ *initrd_size = 0;
+ ret = bs->locate_device_path(&load_file2_guid, &dp, &handle);
+ if (ret != EFI_SUCCESS) {
+ error(L"Load File2 protocol not found\r\n");
+ return ret;
+ }
+ ret = bs->handle_protocol(handle, &load_file2_guid,
+ (void **)&load_file2_prot);
+ ret = load_file2_prot->load_file(load_file2_prot, dp, false,
+ initrd_size, NULL);
+ if (ret != EFI_BUFFER_TOO_SMALL) {
+ error(L"Load File2 protocol does not provide file length\r\n");
+ return EFI_LOAD_ERROR;
+ }
+ ret = bs->allocate_pages(EFI_ALLOCATE_ANY_PAGES, EFI_LOADER_DATA,
+ efi_size_in_pages(*initrd_size), &buffer);
+ if (ret != EFI_SUCCESS) {
+ error(L"Out of memory\r\n");
+ return ret;
+ }
+ *initrd = (void *)buffer;
+ ret = load_file2_prot->load_file(load_file2_prot, dp, false,
+ initrd_size, *initrd);
+ if (ret != EFI_SUCCESS) {
+ error(L"Load File2 protocol failed to provide file\r\n");
+ bs->free_pages(buffer, efi_size_in_pages(*initrd_size));
+ return EFI_LOAD_ERROR;
+ }
+ return ret;
+}
+
+/**
+ * do_load() - load initial RAM disk and display CRC32 and length
+ *
+ * @filename: file name
+ * Return: status code
+ */
+static efi_status_t do_load(void)
+{
+ void *initrd;
+ efi_uintn_t initrd_size;
+ u32 crc32;
+ efi_uintn_t ret;
+
+ ret = get_initrd(&initrd, &initrd_size);
+ if (ret != EFI_SUCCESS)
+ return ret;
+ print(L"length: 0x");
+ printx(initrd_size, 1);
+ print(L"\r\n");
+
+ ret = bs->calculate_crc32(initrd, initrd_size, &crc32);
+ if (ret != EFI_SUCCESS) {
+ error(L"Calculating CRC32 failed\r\n");
+ return EFI_LOAD_ERROR;
+ }
+ print(L"crc32: 0x");
+ printx(crc32, 8);
+ print(L"\r\n");
+
+ return EFI_SUCCESS;
+}
+
+/**
+ * do_save() - save initial RAM disk
+ *
+ * @filename: file name
+ * Return: status code
+ */
+static efi_status_t do_save(u16 *filename)
+{
+ struct efi_loaded_image *loaded_image;
+ struct efi_simple_file_system_protocol *file_system;
+ struct efi_file_handle *root, *file;
+ void *initrd;
+ efi_uintn_t initrd_size;
+ efi_uintn_t ret;
+
+ ret = get_initrd(&initrd, &initrd_size);
+ if (ret != EFI_SUCCESS)
+ return ret;
+
+ filename = skip_whitespace(filename);
+
+ ret = bs->open_protocol(handle, &loaded_image_guid,
+ (void **)&loaded_image, NULL, NULL,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+ if (ret != EFI_SUCCESS) {
+ error(L"Loaded image protocol not found\r\n");
+ goto out;
+ }
+
+ /* Open the simple file system protocol */
+ 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) {
+ error(L"Failed to open simple file system protocol\r\n");
+ goto out;
+ }
+
+ /* Open volume */
+ ret = file_system->open_volume(file_system, &root);
+ if (ret != EFI_SUCCESS) {
+ error(L"Failed to open volume\r\n");
+ goto out;
+ }
+ /* Check if file already exists */
+ ret = root->open(root, &file, filename, EFI_FILE_MODE_READ, 0);
+ if (ret == EFI_SUCCESS) {
+ file->close(file);
+ print(L"Overwrite existing file (y/n)? ");
+ ret = efi_input_yn();
+ print(L"\r\n");
+ if (ret != EFI_SUCCESS) {
+ root->close(root);
+ error(L"Aborted by user\r\n");
+ goto out;
+ }
+ }
+
+ /* 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, &initrd_size, initrd);
+ if (ret != EFI_SUCCESS) {
+ error(L"Failed to write file\r\n");
+ } else {
+ print(filename);
+ print(L" written\r\n");
+ }
+ file->close(file);
+ } else {
+ error(L"Failed to open file\r\n");
+ }
+ root->close(root);
+
+out:
+ if (initrd)
+ bs->free_pages((uintptr_t)initrd,
+ efi_size_in_pages(initrd_size));
+ return ret;
+}
+
+/**
+ * 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)
+{
+ 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(L"INITRD Dump\r\n========\r\n\r\n");
+ cout->set_attribute(cout, EFI_LIGHTBLUE | EFI_BACKGROUND_BLACK);
+
+ for (;;) {
+ u16 command[BUFFER_SIZE];
+ u16 *pos;
+ efi_uintn_t ret;
+
+ print(L"=> ");
+ ret = efi_input(command, sizeof(command));
+ if (ret == EFI_ABORTED)
+ break;
+ pos = skip_whitespace(command);
+ if (starts_with(pos, L"exit"))
+ break;
+ else if (starts_with(pos, L"load"))
+ do_load();
+ else if (starts_with(pos, L"save "))
+ do_save(pos + 5);
+ else
+ do_help();
+ }
+
+ cout->set_attribute(cout, EFI_LIGHTGRAY | EFI_BACKGROUND_BLACK);
+ cout->clear_screen(cout);
+ return EFI_SUCCESS;
+}