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path: root/drivers/firmware/efi/efi-stub-helper.c
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Diffstat (limited to 'drivers/firmware/efi/efi-stub-helper.c')
-rw-r--r--drivers/firmware/efi/efi-stub-helper.c634
1 files changed, 634 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c
new file mode 100644
index 00000000000..eb6d4be9e72
--- /dev/null
+++ b/drivers/firmware/efi/efi-stub-helper.c
@@ -0,0 +1,634 @@
+/*
+ * Helper functions used by the EFI stub on multiple
+ * architectures. This should be #included by the EFI stub
+ * implementation files.
+ *
+ * Copyright 2011 Intel Corporation; author Matt Fleming
+ *
+ * This file is part of the Linux kernel, and is made available
+ * under the terms of the GNU General Public License version 2.
+ *
+ */
+#define EFI_READ_CHUNK_SIZE (1024 * 1024)
+
+/* error code which can't be mistaken for valid address */
+#define EFI_ERROR (~0UL)
+
+
+struct file_info {
+ efi_file_handle_t *handle;
+ u64 size;
+};
+
+static void efi_printk(efi_system_table_t *sys_table_arg, char *str)
+{
+ char *s8;
+
+ for (s8 = str; *s8; s8++) {
+ efi_char16_t ch[2] = { 0 };
+
+ ch[0] = *s8;
+ if (*s8 == '\n') {
+ efi_char16_t nl[2] = { '\r', 0 };
+ efi_char16_printk(sys_table_arg, nl);
+ }
+
+ efi_char16_printk(sys_table_arg, ch);
+ }
+}
+
+#define pr_efi(sys_table, msg) efi_printk(sys_table, "EFI stub: "msg)
+#define pr_efi_err(sys_table, msg) efi_printk(sys_table, "EFI stub: ERROR: "msg)
+
+
+static efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg,
+ efi_memory_desc_t **map,
+ unsigned long *map_size,
+ unsigned long *desc_size,
+ u32 *desc_ver,
+ unsigned long *key_ptr)
+{
+ efi_memory_desc_t *m = NULL;
+ efi_status_t status;
+ unsigned long key;
+ u32 desc_version;
+
+ *map_size = sizeof(*m) * 32;
+again:
+ /*
+ * Add an additional efi_memory_desc_t because we're doing an
+ * allocation which may be in a new descriptor region.
+ */
+ *map_size += sizeof(*m);
+ status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+ *map_size, (void **)&m);
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ *desc_size = 0;
+ key = 0;
+ status = efi_call_early(get_memory_map, map_size, m,
+ &key, desc_size, &desc_version);
+ if (status == EFI_BUFFER_TOO_SMALL) {
+ efi_call_early(free_pool, m);
+ goto again;
+ }
+
+ if (status != EFI_SUCCESS)
+ efi_call_early(free_pool, m);
+
+ if (key_ptr && status == EFI_SUCCESS)
+ *key_ptr = key;
+ if (desc_ver && status == EFI_SUCCESS)
+ *desc_ver = desc_version;
+
+fail:
+ *map = m;
+ return status;
+}
+
+
+static unsigned long __init get_dram_base(efi_system_table_t *sys_table_arg)
+{
+ efi_status_t status;
+ unsigned long map_size;
+ unsigned long membase = EFI_ERROR;
+ struct efi_memory_map map;
+ efi_memory_desc_t *md;
+
+ status = efi_get_memory_map(sys_table_arg, (efi_memory_desc_t **)&map.map,
+ &map_size, &map.desc_size, NULL, NULL);
+ if (status != EFI_SUCCESS)
+ return membase;
+
+ map.map_end = map.map + map_size;
+
+ for_each_efi_memory_desc(&map, md)
+ if (md->attribute & EFI_MEMORY_WB)
+ if (membase > md->phys_addr)
+ membase = md->phys_addr;
+
+ efi_call_early(free_pool, map.map);
+
+ return membase;
+}
+
+/*
+ * Allocate at the highest possible address that is not above 'max'.
+ */
+static efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
+ unsigned long size, unsigned long align,
+ unsigned long *addr, unsigned long max)
+{
+ unsigned long map_size, desc_size;
+ efi_memory_desc_t *map;
+ efi_status_t status;
+ unsigned long nr_pages;
+ u64 max_addr = 0;
+ int i;
+
+ status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size,
+ NULL, NULL);
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ /*
+ * Enforce minimum alignment that EFI requires when requesting
+ * a specific address. We are doing page-based allocations,
+ * so we must be aligned to a page.
+ */
+ if (align < EFI_PAGE_SIZE)
+ align = EFI_PAGE_SIZE;
+
+ nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
+again:
+ for (i = 0; i < map_size / desc_size; i++) {
+ efi_memory_desc_t *desc;
+ unsigned long m = (unsigned long)map;
+ u64 start, end;
+
+ desc = (efi_memory_desc_t *)(m + (i * desc_size));
+ if (desc->type != EFI_CONVENTIONAL_MEMORY)
+ continue;
+
+ if (desc->num_pages < nr_pages)
+ continue;
+
+ start = desc->phys_addr;
+ end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT);
+
+ if ((start + size) > end || (start + size) > max)
+ continue;
+
+ if (end - size > max)
+ end = max;
+
+ if (round_down(end - size, align) < start)
+ continue;
+
+ start = round_down(end - size, align);
+
+ /*
+ * Don't allocate at 0x0. It will confuse code that
+ * checks pointers against NULL.
+ */
+ if (start == 0x0)
+ continue;
+
+ if (start > max_addr)
+ max_addr = start;
+ }
+
+ if (!max_addr)
+ status = EFI_NOT_FOUND;
+ else {
+ status = efi_call_early(allocate_pages,
+ EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
+ nr_pages, &max_addr);
+ if (status != EFI_SUCCESS) {
+ max = max_addr;
+ max_addr = 0;
+ goto again;
+ }
+
+ *addr = max_addr;
+ }
+
+ efi_call_early(free_pool, map);
+fail:
+ return status;
+}
+
+/*
+ * Allocate at the lowest possible address.
+ */
+static efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
+ unsigned long size, unsigned long align,
+ unsigned long *addr)
+{
+ unsigned long map_size, desc_size;
+ efi_memory_desc_t *map;
+ efi_status_t status;
+ unsigned long nr_pages;
+ int i;
+
+ status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size,
+ NULL, NULL);
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ /*
+ * Enforce minimum alignment that EFI requires when requesting
+ * a specific address. We are doing page-based allocations,
+ * so we must be aligned to a page.
+ */
+ if (align < EFI_PAGE_SIZE)
+ align = EFI_PAGE_SIZE;
+
+ nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
+ for (i = 0; i < map_size / desc_size; i++) {
+ efi_memory_desc_t *desc;
+ unsigned long m = (unsigned long)map;
+ u64 start, end;
+
+ desc = (efi_memory_desc_t *)(m + (i * desc_size));
+
+ if (desc->type != EFI_CONVENTIONAL_MEMORY)
+ continue;
+
+ if (desc->num_pages < nr_pages)
+ continue;
+
+ start = desc->phys_addr;
+ end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT);
+
+ /*
+ * Don't allocate at 0x0. It will confuse code that
+ * checks pointers against NULL. Skip the first 8
+ * bytes so we start at a nice even number.
+ */
+ if (start == 0x0)
+ start += 8;
+
+ start = round_up(start, align);
+ if ((start + size) > end)
+ continue;
+
+ status = efi_call_early(allocate_pages,
+ EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
+ nr_pages, &start);
+ if (status == EFI_SUCCESS) {
+ *addr = start;
+ break;
+ }
+ }
+
+ if (i == map_size / desc_size)
+ status = EFI_NOT_FOUND;
+
+ efi_call_early(free_pool, map);
+fail:
+ return status;
+}
+
+static void efi_free(efi_system_table_t *sys_table_arg, unsigned long size,
+ unsigned long addr)
+{
+ unsigned long nr_pages;
+
+ if (!size)
+ return;
+
+ nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
+ efi_call_early(free_pages, addr, nr_pages);
+}
+
+
+/*
+ * Check the cmdline for a LILO-style file= arguments.
+ *
+ * We only support loading a file from the same filesystem as
+ * the kernel image.
+ */
+static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
+ efi_loaded_image_t *image,
+ char *cmd_line, char *option_string,
+ unsigned long max_addr,
+ unsigned long *load_addr,
+ unsigned long *load_size)
+{
+ struct file_info *files;
+ unsigned long file_addr;
+ u64 file_size_total;
+ efi_file_handle_t *fh = NULL;
+ efi_status_t status;
+ int nr_files;
+ char *str;
+ int i, j, k;
+
+ file_addr = 0;
+ file_size_total = 0;
+
+ str = cmd_line;
+
+ j = 0; /* See close_handles */
+
+ if (!load_addr || !load_size)
+ return EFI_INVALID_PARAMETER;
+
+ *load_addr = 0;
+ *load_size = 0;
+
+ if (!str || !*str)
+ return EFI_SUCCESS;
+
+ for (nr_files = 0; *str; nr_files++) {
+ str = strstr(str, option_string);
+ if (!str)
+ break;
+
+ str += strlen(option_string);
+
+ /* Skip any leading slashes */
+ while (*str == '/' || *str == '\\')
+ str++;
+
+ while (*str && *str != ' ' && *str != '\n')
+ str++;
+ }
+
+ if (!nr_files)
+ return EFI_SUCCESS;
+
+ status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+ nr_files * sizeof(*files), (void **)&files);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table_arg, "Failed to alloc mem for file handle list\n");
+ goto fail;
+ }
+
+ str = cmd_line;
+ for (i = 0; i < nr_files; i++) {
+ struct file_info *file;
+ efi_char16_t filename_16[256];
+ efi_char16_t *p;
+
+ str = strstr(str, option_string);
+ if (!str)
+ break;
+
+ str += strlen(option_string);
+
+ file = &files[i];
+ p = filename_16;
+
+ /* Skip any leading slashes */
+ while (*str == '/' || *str == '\\')
+ str++;
+
+ while (*str && *str != ' ' && *str != '\n') {
+ if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16))
+ break;
+
+ if (*str == '/') {
+ *p++ = '\\';
+ str++;
+ } else {
+ *p++ = *str++;
+ }
+ }
+
+ *p = '\0';
+
+ /* Only open the volume once. */
+ if (!i) {
+ status = efi_open_volume(sys_table_arg, image,
+ (void **)&fh);
+ if (status != EFI_SUCCESS)
+ goto free_files;
+ }
+
+ status = efi_file_size(sys_table_arg, fh, filename_16,
+ (void **)&file->handle, &file->size);
+ if (status != EFI_SUCCESS)
+ goto close_handles;
+
+ file_size_total += file->size;
+ }
+
+ if (file_size_total) {
+ unsigned long addr;
+
+ /*
+ * Multiple files need to be at consecutive addresses in memory,
+ * so allocate enough memory for all the files. This is used
+ * for loading multiple files.
+ */
+ status = efi_high_alloc(sys_table_arg, file_size_total, 0x1000,
+ &file_addr, max_addr);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table_arg, "Failed to alloc highmem for files\n");
+ goto close_handles;
+ }
+
+ /* We've run out of free low memory. */
+ if (file_addr > max_addr) {
+ pr_efi_err(sys_table_arg, "We've run out of free low memory\n");
+ status = EFI_INVALID_PARAMETER;
+ goto free_file_total;
+ }
+
+ addr = file_addr;
+ for (j = 0; j < nr_files; j++) {
+ unsigned long size;
+
+ size = files[j].size;
+ while (size) {
+ unsigned long chunksize;
+ if (size > EFI_READ_CHUNK_SIZE)
+ chunksize = EFI_READ_CHUNK_SIZE;
+ else
+ chunksize = size;
+
+ status = efi_file_read(files[j].handle,
+ &chunksize,
+ (void *)addr);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table_arg, "Failed to read file\n");
+ goto free_file_total;
+ }
+ addr += chunksize;
+ size -= chunksize;
+ }
+
+ efi_file_close(files[j].handle);
+ }
+
+ }
+
+ efi_call_early(free_pool, files);
+
+ *load_addr = file_addr;
+ *load_size = file_size_total;
+
+ return status;
+
+free_file_total:
+ efi_free(sys_table_arg, file_size_total, file_addr);
+
+close_handles:
+ for (k = j; k < i; k++)
+ efi_file_close(files[k].handle);
+free_files:
+ efi_call_early(free_pool, files);
+fail:
+ *load_addr = 0;
+ *load_size = 0;
+
+ return status;
+}
+/*
+ * Relocate a kernel image, either compressed or uncompressed.
+ * In the ARM64 case, all kernel images are currently
+ * uncompressed, and as such when we relocate it we need to
+ * allocate additional space for the BSS segment. Any low
+ * memory that this function should avoid needs to be
+ * unavailable in the EFI memory map, as if the preferred
+ * address is not available the lowest available address will
+ * be used.
+ */
+static efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
+ unsigned long *image_addr,
+ unsigned long image_size,
+ unsigned long alloc_size,
+ unsigned long preferred_addr,
+ unsigned long alignment)
+{
+ unsigned long cur_image_addr;
+ unsigned long new_addr = 0;
+ efi_status_t status;
+ unsigned long nr_pages;
+ efi_physical_addr_t efi_addr = preferred_addr;
+
+ if (!image_addr || !image_size || !alloc_size)
+ return EFI_INVALID_PARAMETER;
+ if (alloc_size < image_size)
+ return EFI_INVALID_PARAMETER;
+
+ cur_image_addr = *image_addr;
+
+ /*
+ * The EFI firmware loader could have placed the kernel image
+ * anywhere in memory, but the kernel has restrictions on the
+ * max physical address it can run at. Some architectures
+ * also have a prefered address, so first try to relocate
+ * to the preferred address. If that fails, allocate as low
+ * as possible while respecting the required alignment.
+ */
+ nr_pages = round_up(alloc_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
+ status = efi_call_early(allocate_pages,
+ EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
+ nr_pages, &efi_addr);
+ new_addr = efi_addr;
+ /*
+ * If preferred address allocation failed allocate as low as
+ * possible.
+ */
+ if (status != EFI_SUCCESS) {
+ status = efi_low_alloc(sys_table_arg, alloc_size, alignment,
+ &new_addr);
+ }
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table_arg, "Failed to allocate usable memory for kernel.\n");
+ return status;
+ }
+
+ /*
+ * We know source/dest won't overlap since both memory ranges
+ * have been allocated by UEFI, so we can safely use memcpy.
+ */
+ memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
+
+ /* Return the new address of the relocated image. */
+ *image_addr = new_addr;
+
+ return status;
+}
+
+/*
+ * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
+ * This overestimates for surrogates, but that is okay.
+ */
+static int efi_utf8_bytes(u16 c)
+{
+ return 1 + (c >= 0x80) + (c >= 0x800);
+}
+
+/*
+ * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
+ */
+static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n)
+{
+ unsigned int c;
+
+ while (n--) {
+ c = *src++;
+ if (n && c >= 0xd800 && c <= 0xdbff &&
+ *src >= 0xdc00 && *src <= 0xdfff) {
+ c = 0x10000 + ((c & 0x3ff) << 10) + (*src & 0x3ff);
+ src++;
+ n--;
+ }
+ if (c >= 0xd800 && c <= 0xdfff)
+ c = 0xfffd; /* Unmatched surrogate */
+ if (c < 0x80) {
+ *dst++ = c;
+ continue;
+ }
+ if (c < 0x800) {
+ *dst++ = 0xc0 + (c >> 6);
+ goto t1;
+ }
+ if (c < 0x10000) {
+ *dst++ = 0xe0 + (c >> 12);
+ goto t2;
+ }
+ *dst++ = 0xf0 + (c >> 18);
+ *dst++ = 0x80 + ((c >> 12) & 0x3f);
+ t2:
+ *dst++ = 0x80 + ((c >> 6) & 0x3f);
+ t1:
+ *dst++ = 0x80 + (c & 0x3f);
+ }
+
+ return dst;
+}
+
+/*
+ * Convert the unicode UEFI command line to ASCII to pass to kernel.
+ * Size of memory allocated return in *cmd_line_len.
+ * Returns NULL on error.
+ */
+static char *efi_convert_cmdline(efi_system_table_t *sys_table_arg,
+ efi_loaded_image_t *image,
+ int *cmd_line_len)
+{
+ const u16 *s2;
+ u8 *s1 = NULL;
+ unsigned long cmdline_addr = 0;
+ int load_options_chars = image->load_options_size / 2; /* UTF-16 */
+ const u16 *options = image->load_options;
+ int options_bytes = 0; /* UTF-8 bytes */
+ int options_chars = 0; /* UTF-16 chars */
+ efi_status_t status;
+ u16 zero = 0;
+
+ if (options) {
+ s2 = options;
+ while (*s2 && *s2 != '\n'
+ && options_chars < load_options_chars) {
+ options_bytes += efi_utf8_bytes(*s2++);
+ options_chars++;
+ }
+ }
+
+ if (!options_chars) {
+ /* No command line options, so return empty string*/
+ options = &zero;
+ }
+
+ options_bytes++; /* NUL termination */
+
+ status = efi_low_alloc(sys_table_arg, options_bytes, 0, &cmdline_addr);
+ if (status != EFI_SUCCESS)
+ return NULL;
+
+ s1 = (u8 *)cmdline_addr;
+ s2 = (const u16 *)options;
+
+ s1 = efi_utf16_to_utf8(s1, s2, options_chars);
+ *s1 = '\0';
+
+ *cmd_line_len = options_bytes;
+ return (char *)cmdline_addr;
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 01:44:19 +0000