Nicolas,
Thank you very much, Phil. I downloaded the blob and manually copied
it to /usr/lib/firmware/radeon as root. However, I keep getting the same error. Is there
anything I might be doing wrong here?
The kernel won't usually search there (unless you ask it to).
Try using either /lib/firmware/radeon, or
/lib/firmware/${RELEASE}/radeon, where ${RELEASE}
is the name of the kernel version that you also
see in the kernel modules path (/lib/modules/${...}/...}).
Cheers,
Phil