On Mon, May 27, 2024 at 02:42:44PM GMT, Dmitry Baryshkov wrote: > On Thu, 23 May 2024 at 01:48, Bjorn Andersson <quic_bjorande@xxxxxxxxxxx> wrote: > > > > On Tue, May 21, 2024 at 03:08:31PM +0200, Dmitry Baryshkov wrote: > > > On Tue, 21 May 2024 at 13:20, Kalle Valo <kvalo@xxxxxxxxxx> wrote: > > > > > > > > Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> writes: > > > > > > > > > On Tue, 21 May 2024 at 12:52, <neil.armstrong@xxxxxxxxxx> wrote: > > > > >> > > > > >> On 21/05/2024 11:45, Dmitry Baryshkov wrote: > > > > >> > Qualcomm platforms have different sets of the firmware files, which > > > > >> > differ from platform to platform (and from board to board, due to the > > > > >> > embedded signatures). Rather than listing all the firmware files, > > > > >> > including full paths, in the DT, provide a way to determine firmware > > > > >> > path based on the root DT node compatible. > > > > >> > > > > >> Ok this looks quite over-engineered but necessary to handle the legacy, > > > > >> but I really think we should add a way to look for a board-specific path > > > > >> first and fallback to those SoC specific paths. > > > > > > > > > > Again, CONFIG_FW_LOADER_USER_HELPER => delays. > > > > > > > > To me this also looks like very over-engineered, can you elaborate more > > > > why this is needed? Concrete examples would help to understand better. > > > > > > Sure. During the meeting last week Arnd suggested evaluating if we can > > > drop firmware-name from the board DT files. Several reasons for that: > > > - DT should describe the hardware, not the Linux-firmware locations > > > - having firmware name in DT complicates updating the tree to use > > > different firmware API (think of mbn vs mdt vs any other format) > > > - If the DT gets supplied by the vendor (e.g. for > > > SystemReady-certified devices), there should be a sync between the > > > vendor's DT, linux kernel and the rootfs. Dropping firmware names from > > > DT solves that by removing one piece of the equation > > > > > > Now for the complexity of the solution. Each SoC family has their own > > > firmware set. This includes firmware for the DSPs, for modem, WiFi > > > bits, GPU shader, etc. > > > For the development boards these devices are signed by the testing key > > > and the actual signature is not validated against the root of trust > > > certificate. > > > For the end-user devices the signature is actually validated against > > > the bits fused to the SoC during manufacturing process. CA certificate > > > (and thus the fuses) differ from vendor to vendor (and from the device > > > to device) > > > > > > Not all of the firmware files are a part of the public linux-firmware > > > tree. However we need to support the rootfs bundled with the firmware > > > for different platforms (both public and vendor). The non-signed files > > > come from the Adreno GPU and can be shared between platforms. All > > > other files are SoC-specific and in some cases device-specific. > > > > > > So for example the SDM845 db845c (open device) loads following firmware files: > > > Not signed: > > > - qcom/a630_sqe.fw > > > - qcom/a630_gmu.bin > > > > > > Signed, will work for any non-secured sdm845 device: > > > - qcom/sdm845/a630_zap.mbn > > > - qcom/sdm845/adsp.mbn > > > - qcom/sdm845/cdsp.mbn > > > - qcom/sdm485/mba.mbn > > > - qcom/sdm845/modem.mbn > > > - qcom/sdm845/wlanmdsp.mbn (loaded via TQFTP) > > > - qcom/venus-5.2/venus.mbn > > > > > > Signed, works only for DB845c. > > > - qcom/sdm845/Thundercomm/db845c/slpi.mbn > > > > > > In comparison, the SDM845 Pixel-3 phone (aka blueline) should load the > > > following firmware files: > > > - qcom/a630_sqe.fw (the same, non-signed file) > > > - qcom/a630_gmu.bin (the same, non-signed file) > > > - qcom/sdm845/Google/blueline/a630_zap.mbn > > > > How do you get from "a630_zap.mbn" to this? By extending the lookup > > table for every target, or what am I missing? > > More or less so. Matching the root OF node gives us the firmware > location, then it gets prepended to all firmware targets. Not an ideal > solution, as there is no fallback support, but at least it gives us > some points to discuss (and to decide whether to move to some > particular direction or to abandon the idea completely, making Arnd > unhappy again). > I understand the desire to not put linux-firmware-specific paths in the DeviceTree, but I think I'm less keen on having a big lookup table in the kernel... Regards, Bjorn
