1 // SPDX-License-Identifier: GPL-2.0
3 * Boot config tool for initrd image
14 #include <linux/kernel.h>
15 #include <linux/bootconfig.h>
17 static int xbc_show_array(struct xbc_node *node)
22 xbc_array_for_each_value(node, val) {
23 printf("\"%s\"%s", val, node->next ? ", " : ";\n");
29 static void xbc_show_compact_tree(void)
31 struct xbc_node *node, *cnode;
34 node = xbc_root_node();
35 while (node && xbc_node_is_key(node)) {
36 for (i = 0; i < depth; i++)
38 cnode = xbc_node_get_child(node);
39 while (cnode && xbc_node_is_key(cnode) && !cnode->next) {
40 printf("%s.", xbc_node_get_data(node));
42 cnode = xbc_node_get_child(node);
44 if (cnode && xbc_node_is_key(cnode)) {
45 printf("%s {\n", xbc_node_get_data(node));
49 } else if (cnode && xbc_node_is_value(cnode)) {
50 printf("%s = ", xbc_node_get_data(node));
52 xbc_show_array(cnode);
54 printf("\"%s\";\n", xbc_node_get_data(cnode));
56 printf("%s;\n", xbc_node_get_data(node));
60 node = xbc_node_get_next(node);
64 node = xbc_node_get_parent(node);
67 if (!xbc_node_get_child(node)->next)
70 for (i = 0; i < depth; i++)
74 node = xbc_node_get_next(node);
78 /* Simple real checksum */
79 int checksum(unsigned char *buf, int len)
83 for (i = 0; i < len; i++)
89 #define PAGE_SIZE 4096
91 int load_xbc_fd(int fd, char **buf, int size)
95 *buf = malloc(size + 1);
99 ret = read(fd, *buf, size);
107 /* Return the read size or -errno */
108 int load_xbc_file(const char *path, char **buf)
113 fd = open(path, O_RDONLY);
116 ret = fstat(fd, &stat);
120 ret = load_xbc_fd(fd, buf, stat.st_size);
127 int load_xbc_from_initrd(int fd, char **buf)
131 u32 size = 0, csum = 0, rcsum;
132 char magic[BOOTCONFIG_MAGIC_LEN];
134 ret = fstat(fd, &stat);
138 if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)
141 if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0) {
142 pr_err("Failed to lseek: %d\n", -errno);
145 if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
147 /* Check the bootconfig magic bytes */
148 if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)
151 if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0) {
152 pr_err("Failed to lseek: %d\n", -errno);
156 if (read(fd, &size, sizeof(u32)) < 0)
159 if (read(fd, &csum, sizeof(u32)) < 0)
162 /* Wrong size error */
163 if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {
164 pr_err("bootconfig size is too big\n");
168 if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),
170 pr_err("Failed to lseek: %d\n", -errno);
174 ret = load_xbc_fd(fd, buf, size);
179 rcsum = checksum((unsigned char *)*buf, size);
181 pr_err("checksum error: %d != %d\n", csum, rcsum);
185 ret = xbc_init(*buf);
193 int show_xbc(const char *path)
198 fd = open(path, O_RDONLY);
200 pr_err("Failed to open initrd %s: %d\n", path, fd);
204 ret = load_xbc_from_initrd(fd, &buf);
206 pr_err("Failed to load a boot config from initrd: %d\n", ret);
208 xbc_show_compact_tree();
216 int delete_xbc(const char *path)
219 int ret = 0, fd, size;
222 fd = open(path, O_RDWR);
224 pr_err("Failed to open initrd %s: %d\n", path, fd);
228 size = load_xbc_from_initrd(fd, &buf);
231 pr_err("Failed to load a boot config from initrd: %d\n", ret);
232 } else if (size > 0) {
233 ret = fstat(fd, &stat);
235 ret = ftruncate(fd, stat.st_size
236 - size - 8 - BOOTCONFIG_MAGIC_LEN);
239 } /* Ignore if there is no boot config in initrd */
247 int apply_xbc(const char *path, const char *xbc_path)
253 ret = load_xbc_file(xbc_path, &buf);
255 pr_err("Failed to load %s : %d\n", xbc_path, ret);
258 size = strlen(buf) + 1;
259 csum = checksum((unsigned char *)buf, size);
261 /* Prepare xbc_path data */
262 data = malloc(size + 8);
266 *(u32 *)(data + size) = size;
267 *(u32 *)(data + size + 4) = csum;
269 /* Check the data format */
272 pr_err("Failed to parse %s: %d\n", xbc_path, ret);
277 printf("Apply %s to %s\n", xbc_path, path);
278 printf("\tNumber of nodes: %d\n", ret);
279 printf("\tSize: %u bytes\n", (unsigned int)size);
280 printf("\tChecksum: %d\n", (unsigned int)csum);
282 /* TODO: Check the options by schema */
286 /* Remove old boot config if exists */
287 ret = delete_xbc(path);
289 pr_err("Failed to delete previous boot config: %d\n", ret);
294 fd = open(path, O_RDWR | O_APPEND);
296 pr_err("Failed to open %s: %d\n", path, fd);
299 /* TODO: Ensure the @path is initramfs/initrd image */
300 ret = write(fd, data, size + 8);
302 pr_err("Failed to apply a boot config: %d\n", ret);
305 /* Write a magic word of the bootconfig */
306 ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
308 pr_err("Failed to apply a boot config magic: %d\n", ret);
319 printf("Usage: bootconfig [OPTIONS] <INITRD>\n"
320 " Apply, delete or show boot config to initrd.\n"
322 " -a <config>: Apply boot config to initrd\n"
323 " -d : Delete boot config file from initrd\n\n"
324 " If no option is given, show current applied boot config.\n");
328 int main(int argc, char **argv)
335 while ((opt = getopt(argc, argv, "hda:")) != -1) {
349 if (apply && delete) {
350 pr_err("Error: You can not specify both -a and -d at once.\n");
354 if (optind >= argc) {
355 pr_err("Error: No initrd is specified.\n");
362 return apply_xbc(path, apply);
364 return delete_xbc(path);
366 return show_xbc(path);