49 lines
1.8 KiB
Markdown
49 lines
1.8 KiB
Markdown
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# QEMU AArch64 emulator
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This page discribes how to build and run coreboot for QEMU/AArch64.
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You can use LinuxBoot via `make menuconfig` or an arbitrary FIT image
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as a payload for QEMU/AArch64.
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## Running coreboot in QEMU
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```bash
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qemu-system-aarch64 -bios ./build/coreboot.rom \
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-M virt,secure=on,virtualization=on -cpu cortex-a53 \
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-nographic -m 8192M
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```
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- The default CPU in QEMU for AArch64 is a cortex-a15 which is 32-bit
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ARM CPU. You need to specify 64-bit ARM CPU via `-cpu cortex-a53`.
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- The default privilege level in QEMU for AArch64 is EL1 that we can't
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have the right to access EL3/EL2 registers. You need to enable EL3/EL2
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via `-machine secure=on,virtualization=on`.
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- You need to specify the size of memory more than 544 MiB because 512
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MiB is reserved for the kernel.
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- The maximum size of memory is 255GiB (-m 261120).
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## Building coreboot with an arbitrary FIT payload
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There are 3 steps to make coreboot.rom for QEMU/AArch64. If you select
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LinuxBoot, step 2 and 3 have done by LinuxBoot.
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1. Get a DTB (Device Tree Blob)
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2. Build a FIT image with a DTB
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3. Add a FIT image to coreboot.rom
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### 1. Get a DTB
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You can get the DTB from QEMU with the following command.
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```
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$ qemu-system-aarch64 \
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-M virt,dumpdtb=virt.dtb,secure=on,virtualization=on \
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-cpu cortex-a53 -nographic -m 8192M
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```
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### 2. Build a FIT image with a DTB
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You need to write an image source file that has an `.its` extension to
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configure kernels, ramdisks, and DTBs.
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See [Flattened uImage Tree documentation](../../lib/payloads/fit.md) for more details.
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### 3. Add a FIT image to coreboot.rom
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You can use cbfstool to add the payload you created in step 2 to
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the coreboot.rom.
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```
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$ ./build/cbfstool ./build/coreboot.rom add -f <path-to-a-payload>/uImage \
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-n fallback/payload -t fit -c lzma
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```
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