[PATCH 3/3] firmware loader: allow distribution to choose default search paths
From: Ming Lei
Date: Wed Jun 05 2013 - 01:43:51 EST
For some distributions(e.g. android), firmware images aren't put
under kernel built-in search paths, so introduce one Kconfig
option to allow distributions or users to choose its specific default
search paths, which are always tried before searching from kernel
built-in paths in direct loading.
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx>
---
drivers/base/Kconfig | 12 +++++++
drivers/base/firmware_class.c | 76 ++++++++++++++++++++++++++++++++++++-----
2 files changed, 80 insertions(+), 8 deletions(-)
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 07abd9d..5b0c909 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -156,6 +156,18 @@ config FW_LOADER_USER_HELPER
no longer required unless you have a special firmware file that
resides in a non-standard path.
+config FW_CUSTOMIZED_PATH
+ string "default firmware search paths for direct loading"
+ help
+ On some distribution(e.g. android), firmware images aren't
+ put under kernel built-in search paths, so provide this option
+ for distributions to choose a distribution specific firmware
+ search path. The option allows to choose more than one path,
+ and paths are seperated with semicolon(e.g. on android, the
+ option might look as "/etc/firmware;/vendor/firmware").
+
+ If you are unsure about this, don't choose here.
+
config DEBUG_DRIVER
bool "Driver Core verbose debug messages"
depends on DEBUG_KERNEL
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index c743409..50b5913 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -267,6 +267,9 @@ static void fw_free_buf(struct firmware_buf *buf)
static char fw_path_para[256];
static const char * const fw_path[] = {
fw_path_para,
+#ifdef CONFIG_FW_CUSTOMIZED_PATH
+ CONFIG_FW_CUSTOMIZED_PATH,
+#endif
"/lib/firmware/updates/" UTS_RELEASE,
"/lib/firmware/updates",
"/lib/firmware/" UTS_RELEASE,
@@ -314,6 +317,59 @@ static bool fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf
return true;
}
+static bool fw_get_file_firmware(const char *path,
+ struct firmware_buf *buf)
+{
+ struct file *file;
+ bool success;
+
+ file = filp_open(path, O_RDONLY, 0);
+ if (IS_ERR(file))
+ return false;
+ success = fw_read_file_contents(file, buf);
+ fput(file);
+
+ return success;
+}
+
+#ifdef CONFIG_FW_CUSTOMIZED_PATH
+/* The path in @paths is seperated by ';' */
+static bool fw_get_fw_file_from_paths(const char *paths, char *path,
+ struct firmware_buf *buf)
+{
+ int len, start, end;
+ char *pos;
+
+ end = -1;
+ do {
+ start = end + 1;
+ pos = strchr(&paths[start], ';');
+ if (pos) {
+ end = (int)(pos - paths);
+ len = end - start;
+ } else {
+ len = strlen(&paths[start]);
+ }
+
+ if (PATH_MAX < len + strlen(buf->fw_id))
+ continue;
+ strncpy(path, &paths[start], len);
+ snprintf(&path[len], PATH_MAX - len, "/%s", buf->fw_id);
+
+ if (fw_get_file_firmware(path, buf))
+ return true;
+ } while (pos && end < strlen(paths) - 1);
+
+ return false;
+}
+#else
+static bool fw_get_fw_file_from_paths(const char *paths, char *path,
+ struct firmware_buf *buf)
+{
+ return false;
+}
+#endif
+
static bool fw_get_filesystem_firmware(struct device *device,
struct firmware_buf *buf)
{
@@ -322,19 +378,23 @@ static bool fw_get_filesystem_firmware(struct device *device,
char *path = __getname();
for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
- struct file *file;
/* skip the unset customized path */
if (!fw_path[i][0])
continue;
- snprintf(path, PATH_MAX, "%s/%s", fw_path[i], buf->fw_id);
-
- file = filp_open(path, O_RDONLY, 0);
- if (IS_ERR(file))
- continue;
- success = fw_read_file_contents(file, buf);
- fput(file);
+ /*
+ * If CONFIG_FW_CUSTOMIZED_PATH is set, search from
+ * these paths first
+ */
+ if (i == 1 && ARRAY_SIZE(fw_path) > 5) {
+ success = fw_get_fw_file_from_paths(fw_path[1],
+ path, buf);
+ } else {
+ snprintf(path, PATH_MAX, "%s/%s", fw_path[i],
+ buf->fw_id);
+ success = fw_get_file_firmware(path, buf);
+ }
if (success)
break;
}
--
1.7.9.5
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