qebspil (Qualcomm Exit Boot Services Peripheral Image Loader) is an UEFI boot driver that allows starting co-processors (such as DSPs) on Qualcomm platforms late during the boot process (shortly before the bootloader exits UEFI using ExitBootServices()). This can be used to start co-processors early, independent of the selected operating system, and without disrupting the normal UEFI boot flow. Possible use cases include (for example):

• Start full DSP firmwares for operating system configurations that do not support DSP startup/firmware loading (e.g. EL2/virtualization-enabled Linux configurations on most Qualcomm compute/laptop platforms).

• Make use of DSP services early during operating system startup.

Note: This is a spare time project not affiliated with Qualcomm or Linaro.

• Qualcomm Snapdragon 7c Compute Platform (SC7180)
• Qualcomm Snapdragon 8cx Gen 3 Compute Platform (SC8280XP)
• Qualcomm Snapdragon X Elite (X1E)

1. Make sure you have the aarch64-linux-gnu-gcc cross compiler installed. (If you want to build natively, omit CROSS_COMPILE= in the make command).

2. Make sure you have submodules checked out and up to date:

   $ git submodule update --init --recursive
   

3. Build qebspil using make:

   $ make CROSS_COMPILE=aarch64-linux-gnu-
   

4. The output file is located at out/qebspilaa64.efi.

Currently, qebspil becomes active only when a device tree is installed by the bootloader (e.g. when booting Linux using systemd-boot or GRUB). Only co-processors (remoteprocs) enabled in the device tree will be started.

In addition, by default only remoteprocs with the qcom,broken-reset property are started. This is intended to allow compatibility with standard Linux configurations, where the remoteprocs are expected to be off during boot and are later started by Linux during the boot process. To start all remoteprocs even without this property, build qebspil with the QEBSPIL_ALWAYS_START=1 option in the make command line.

To use qebspil with Linux, additional patches are currently needed to allow taking over the firmware started early by qebspil. They can be found in the following branches:

• Linux 6.16: https://git.codelinaro.org/stephan.gerhold/linux/-/tree/wip/x1e80100-6.16-el2
• Linux 6.17: https://git.codelinaro.org/stephan.gerhold/linux/-/tree/wip/qcom-laptops-6.17-el2

qebspil is an UEFI boot driver, it can be loaded manually from the EFI shell or loaded automatically by the UEFI firmware and/or bootloader.

For initial testing, copy qebspilaa64.efi to an USB flash drive together with the necessary firmware (see Firmware below). Then load it from an EFI shell as follows:

# First navigate to USB flash drive using fsXY: (check e.g. using "ls")
fsXY:\> load qebspilaa64.efi

Loading qebspil automatically is easiest when using systemd-boot: Copy qebspilaa64.efi to your EFI System Partition (ESP) at /EFI/systemd/drivers/qebspilaa64.efi. Note that the firmware must be also copied to the ESP, to the top-level /firmware directory as described below.

qebspil needs access to the remoteproc firmware to start co-processors early. The firmware-name is used from the device tree to allow creating generic boot images (e.g. in combination with dtbloader, UKIs or similar). All firmware files should be placed in the same partition as qebspilaa64.efi in a top-level /firmware directory, e.g.:

/firmware/
└── qcom/
    ├── sc8280xp/
    │   └── LENOVO/
    │       └── 21BX/
    │           ├── qcadsp8280.mbn
    │           ├── qccdsp8280.mbn
    │           └── qcslpi8280.mbn
    └── x1e80100/
        └── LENOVO/
            └── 21N1/
                ├── adsp_dtbs.elf
                ├── cdsp_dtbs.elf
                ├── qcadsp8380.mbn
                └── qccdsp8380.mbn

To find the necessary firmware files on a running system, you can use e.g.:

$ find /sys/firmware/devicetree -name firmware-name -exec cat {} + | xargs -0n1

Alternatively, search for the firmware-name properties in the device tree source code. The firmware files used by Linux are typically loaded from /lib/firmware/. You may need to copy the firmware files from the Windows partition if they are not part of upstream linux-firmware.

To maintain compatibility with the Linux kernel, this project is licensed under the GNU General Public License v2.0 only (GPL-2.0-only). Contributions welcome!

qebspil includes code from the following third-party projects:

• gnu-efi
• dtc
• Portions of EDK2
• Portions of Qualcomm's ABL bootloader, to interface with the secure firmware
• Portions of lk2nd

The licensing for this code can be found in the respective source code files.