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];
135 ret = fstat(fd, &stat);
139 if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)
142 if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0) {
143 pr_err("Failed to lseek: %d\n", -errno);
146 if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
148 /* Check the bootconfig magic bytes */
149 if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)
152 if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0) {
153 pr_err("Failed to lseek: %d\n", -errno);
157 if (read(fd, &size, sizeof(u32)) < 0)
160 if (read(fd, &csum, sizeof(u32)) < 0)
163 /* Wrong size error */
164 if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {
165 pr_err("bootconfig size is too big\n");
169 if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),
171 pr_err("Failed to lseek: %d\n", -errno);
175 ret = load_xbc_fd(fd, buf, size);
180 rcsum = checksum((unsigned char *)*buf, size);
182 pr_err("checksum error: %d != %d\n", csum, rcsum);
186 ret = xbc_init(*buf, &msg, NULL);
189 pr_err("parse error: %s.\n", msg);
196 int show_xbc(const char *path)
201 fd = open(path, O_RDONLY);
203 pr_err("Failed to open initrd %s: %d\n", path, fd);
207 ret = load_xbc_from_initrd(fd, &buf);
209 pr_err("Failed to load a boot config from initrd: %d\n", ret);
211 xbc_show_compact_tree();
219 int delete_xbc(const char *path)
222 int ret = 0, fd, size;
225 fd = open(path, O_RDWR);
227 pr_err("Failed to open initrd %s: %d\n", path, fd);
231 size = load_xbc_from_initrd(fd, &buf);
234 pr_err("Failed to load a boot config from initrd: %d\n", ret);
235 } else if (size > 0) {
236 ret = fstat(fd, &stat);
238 ret = ftruncate(fd, stat.st_size
239 - size - 8 - BOOTCONFIG_MAGIC_LEN);
242 } /* Ignore if there is no boot config in initrd */
250 static void show_xbc_error(const char *data, const char *msg, int pos)
255 pr_err("Error: %s.\n", msg);
259 /* Note that pos starts from 0 but lin and col should start from 1. */
261 for (i = 0; i < pos; i++) {
262 if (data[i] == '\n') {
267 pr_err("Parse Error: %s at %d:%d\n", msg, lin, col);
271 int apply_xbc(const char *path, const char *xbc_path)
279 ret = load_xbc_file(xbc_path, &buf);
281 pr_err("Failed to load %s : %d\n", xbc_path, ret);
284 size = strlen(buf) + 1;
285 csum = checksum((unsigned char *)buf, size);
287 /* Prepare xbc_path data */
288 data = malloc(size + 8);
292 *(u32 *)(data + size) = size;
293 *(u32 *)(data + size + 4) = csum;
295 /* Check the data format */
296 ret = xbc_init(buf, &msg, &pos);
298 show_xbc_error(data, msg, pos);
304 printf("Apply %s to %s\n", xbc_path, path);
305 printf("\tNumber of nodes: %d\n", ret);
306 printf("\tSize: %u bytes\n", (unsigned int)size);
307 printf("\tChecksum: %d\n", (unsigned int)csum);
309 /* TODO: Check the options by schema */
313 /* Remove old boot config if exists */
314 ret = delete_xbc(path);
316 pr_err("Failed to delete previous boot config: %d\n", ret);
321 fd = open(path, O_RDWR | O_APPEND);
323 pr_err("Failed to open %s: %d\n", path, fd);
326 /* TODO: Ensure the @path is initramfs/initrd image */
327 ret = write(fd, data, size + 8);
329 pr_err("Failed to apply a boot config: %d\n", ret);
332 /* Write a magic word of the bootconfig */
333 ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
335 pr_err("Failed to apply a boot config magic: %d\n", ret);
346 printf("Usage: bootconfig [OPTIONS] <INITRD>\n"
347 " Apply, delete or show boot config to initrd.\n"
349 " -a <config>: Apply boot config to initrd\n"
350 " -d : Delete boot config file from initrd\n\n"
351 " If no option is given, show current applied boot config.\n");
355 int main(int argc, char **argv)
362 while ((opt = getopt(argc, argv, "hda:")) != -1) {
376 if (apply && delete) {
377 pr_err("Error: You can not specify both -a and -d at once.\n");
381 if (optind >= argc) {
382 pr_err("Error: No initrd is specified.\n");
389 return apply_xbc(path, apply);
391 return delete_xbc(path);
393 return show_xbc(path);