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diff --git a/docs/plat/qemu.rst b/docs/plat/qemu.rst new file mode 100644 index 00000000..4e2cd7c5 --- /dev/null +++ b/docs/plat/qemu.rst @@ -0,0 +1,48 @@ +ARM Trusted Firmware for QEMU virt ARMv8-A +========================================== + +ARM Trusted Firmware 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 defonfig v4.5 Linux kernel is known to boot, FTD 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 |