Arch Linux

miro279

Member

Registered: 2010-10-02

Posts: 153

load firmwar from userspace

I'd like to load firmware for a usb wifi dongle from a different place than /usr/lib/firmware/ if possible.
The original firmware still is in /usr/lib/firmware/ but I have a different version somewhere else. Is this possible?
Thanks!

mich41

Member

Registered: 2012-06-22

Posts: 796

Re: load firmwar from userspace

That's tricky because nowadays the kernel itself loads any firmware it wants.

/* direct firmware loading support */
static char fw_path_para[256];
static const char * const fw_path[] = {
        fw_path_para,
        "/lib/firmware/updates/" UTS_RELEASE,
        "/lib/firmware/updates",
        "/lib/firmware/" UTS_RELEASE,
        "/lib/firmware"
};

/*
 * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 * from kernel command line because firmware_class is generally built in
 * kernel instead of module.
 */
module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");

So it seems you have two choices: put your custom firmware in /usr/lib/firmware/updates (optionally /kernel-version) or set firmware_class.path boot parameter to point to whatever directory contains this FW.