Add a -C option that finds the "kernel" subtree of a bootconfig file
and prints it as a flat, space-separated cmdline string by calling the
shared xbc_snprint_cmdline() renderer. An empty or absent kernel.*
subtree produces empty output and exits successfully.
This lets the kernel build embed a bootconfig file as a plain cmdline
string at build time, so embedded bootconfig values can reach
parse_early_param() during architecture setup without parsing the
bootconfig at runtime.
The renderer is intentionally limited to the kernel.* subtree: that is
the only thing the kernel build needs to embed; init.* and other
subtrees keep going through the runtime parser.
Example of this new mode:
# cat /tmp/test.bconf
kernel {
foo = bar
baz = "hello world"
arr = 1, 2
}
init.foo = nope
# ./tools/bootconfig/bootconfig -C /tmp/test.bconf
foo=bar baz="hello world" arr=1 arr=2 %
Signed-off-by: Breno Leitao <[email protected]>
---
tools/bootconfig/main.c | 60 ++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 52 insertions(+), 8 deletions(-)
diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
index 643f707b8f1da..e1bfab044fbcb 100644
--- a/tools/bootconfig/main.c
+++ b/tools/bootconfig/main.c
@@ -286,7 +286,41 @@ static int init_xbc_with_error(char *buf, int len)
return ret;
}
-static int show_xbc(const char *path, bool list)
+static int show_xbc_kernel_cmdline(void)
+{
+ struct xbc_node *root;
+ char *buf = NULL;
+ int len, ret;
+
+ root = xbc_find_node("kernel");
+ if (!root)
+ return 0; /* no kernel.* keys: emit empty output */
+
+ len = xbc_snprint_cmdline(NULL, 0, root);
+ if (len < 0) {
+ pr_err("Failed to size cmdline output: %d\n", len);
+ return len;
+ }
+ if (len == 0)
+ return 0;
+
+ buf = malloc(len + 1);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = xbc_snprint_cmdline(buf, len + 1, root);
+ if (ret < 0) {
+ pr_err("Failed to render cmdline output: %d\n", ret);
+ free(buf);
+ return ret;
+ }
+
+ fputs(buf, stdout);
+ free(buf);
+ return 0;
+}
+
+static int show_xbc(const char *path, bool list, bool render_cmdline)
{
int ret, fd;
char *buf = NULL;
@@ -322,11 +356,14 @@ static int show_xbc(const char *path, bool list)
if (init_xbc_with_error(buf, ret) < 0)
goto out;
}
- if (list)
+ if (render_cmdline)
+ ret = show_xbc_kernel_cmdline();
+ else if (list)
xbc_show_list();
else
xbc_show_compact_tree();
- ret = 0;
+ if (ret > 0)
+ ret = 0;
out:
free(buf);
@@ -486,7 +523,10 @@ static int usage(void)
" Options:\n"
" -a <config>: Apply boot config to initrd\n"
" -d : Delete boot config file from initrd\n"
- " -l : list boot config in initrd or file\n\n"
+ " -l : list boot config in initrd or file\n"
+ " -C : render the kernel.* subtree as a flat
cmdline\n"
+ " string (suitable for embedding in a kernel
image)\n"
+ " and print it to stdout\n\n"
" If no option is given, show the bootconfig in the given
file.\n");
return -1;
}
@@ -495,10 +535,11 @@ int main(int argc, char **argv)
{
char *path = NULL;
char *apply = NULL;
+ bool render_cmdline = false;
bool delete = false, list = false;
int opt;
- while ((opt = getopt(argc, argv, "hda:l")) != -1) {
+ while ((opt = getopt(argc, argv, "hda:lC")) != -1) {
switch (opt) {
case 'd':
delete = true;
@@ -509,14 +550,17 @@ int main(int argc, char **argv)
case 'l':
list = true;
break;
+ case 'C':
+ render_cmdline = true;
+ break;
case 'h':
default:
return usage();
}
}
- if ((apply && delete) || (delete && list) || (apply && list)) {
- pr_err("Error: You can give one of -a, -d or -l at once.\n");
+ if ((!!apply + !!delete + !!list + !!render_cmdline) > 1) {
+ pr_err("Error: You can give one of -a, -d, -l or -C at
once.\n");
return usage();
}
@@ -532,5 +576,5 @@ int main(int argc, char **argv)
else if (delete)
return delete_xbc(path);
- return show_xbc(path, list);
+ return show_xbc(path, list, render_cmdline);
}
--
2.53.0-Meta
