| Trusted Firmware-A for QEMU virt Armv8-A |
| ======================================== |
| |
| Trusted Firmware-A (TF-A) implements the EL3 firmware layer for QEMU virt |
| Armv8-A. BL1 is used as the BootROM, supplied with the -bios argument. |
| When QEMU starts all CPUs are released simultaneously, BL1 selects a |
| primary CPU to handle the boot and the secondaries are placed in a polling |
| loop to be released by normal world via PSCI. |
| |
| BL2 edits the Flattened Device Tree, FDT, generated by QEMU at run-time to |
| add a node describing PSCI and also enable methods for the CPUs. |
| |
| An ARM64 defconfig v4.5 Linux kernel is known to boot, FDT doesn't need to be |
| provided as it's generated by QEMU. |
| |
| Current limitations: |
| |
| - Only cold boot is supported |
| - No build instructions for QEMU\_EFI.fd and rootfs-arm64.cpio.gz |
| - No instructions for how to load a BL32 (Secure Payload) |
| |
| ``QEMU_EFI.fd`` can be dowloaded from |
| http://snapshots.linaro.org/components/kernel/leg-virt-tianocore-edk2-upstream/latest/QEMU-KERNEL-AARCH64/RELEASE_GCC49/QEMU_EFI.fd |
| |
| Boot binaries, except BL1, are primarily loaded via semi-hosting so all |
| binaries has to reside in the same directory as QEMU is started from. This |
| is conveniently achieved with symlinks the local names as: |
| |
| - ``bl2.bin`` -> BL2 |
| - ``bl31.bin`` -> BL31 |
| - ``bl33.bin`` -> BL33 (``QEMU_EFI.fd``) |
| - ``Image`` -> linux/Image |
| |
| To build: |
| |
| :: |
| |
| make CROSS_COMPILE=aarch64-none-elf- PLAT=qemu |
| |
| To start (QEMU v2.6.0): |
| |
| :: |
| |
| qemu-system-aarch64 -nographic -machine virt,secure=on -cpu cortex-a57 \ |
| -kernel Image \ |
| -append console=ttyAMA0,38400 keep_bootcon root=/dev/vda2 \ |
| -initrd rootfs-arm64.cpio.gz -smp 2 -m 1024 -bios bl1.bin \ |
| -d unimp -semihosting-config enable,target=native |
