path: root/Documentation/firmware_class
diff options
authorMing Lei <>2012-11-03 17:47:58 +0800
committerGreg Kroah-Hartman <>2012-11-14 15:07:18 -0800
commit27602842060484b564cd725241b402b0bddfb830 (patch)
tree62bc5aa301675cde89a7543d169b38e62df1bcd3 /Documentation/firmware_class
parent60dac5e284fe99751e3beefe1a9cc7a0771ad73c (diff)
firmware loader: introduce module parameter to customize(v4) fw search path
This patch introduces one module parameter of 'path' in firmware_class to support customizing firmware image search path, so that people can use its own firmware path if the default built-in paths can't meet their demand[1], and the typical usage is passing the below from kernel command parameter when 'firmware_class' is built in kernel: firmware_class.path=$CUSTOMIZED_PATH [1], Cc: Linus Torvalds <> Signed-off-by: Ming Lei <> Signed-off-by: Greg Kroah-Hartman <>
Diffstat (limited to 'Documentation/firmware_class')
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/firmware_class/README b/Documentation/firmware_class/README
index 815b711bcd85..e9fce78c4137 100644
--- a/Documentation/firmware_class/README
+++ b/Documentation/firmware_class/README
@@ -22,12 +22,17 @@
- calls request_firmware(&fw_entry, $FIRMWARE, device)
- kernel searchs the fimware image with name $FIRMWARE directly
in the below search path of root filesystem:
+ User customized search path by module parameter 'path'[1]
"/lib/firmware/updates/" UTS_RELEASE,
"/lib/firmware/" UTS_RELEASE,
- If found, goto 7), else goto 2)
+ [1], the 'path' is a string parameter which length should be less
+ than 256, user should pass 'firmware_class.path=$CUSTOMIZED_PATH'
+ if firmware_class is built in kernel(the general situation)
2), userspace:
- /sys/class/firmware/xxx/{loading,data} appear.
- hotplug gets called with a firmware identifier in $FIRMWARE