Merge manifest into the board DT, add boot flow drivers
Hafnium currently supports two kinds of boot flow:
(a) Linux-like, where the board FDT is passed by the boot loader to
the OS kernel in first kernel arg (this is used by QEMU, FVP, RPi, ...),
(b) Android-like, where the FDT used by Hafnium is compiled into it and
the VMs have their own.
This used to be implemented using weak symbols and each board spec
overriding it with its own implementation. This patch introduces the
concept of boot-flow drivers in the main tree, and the corresponding
driver selected using a config option in board spec. Drivers for the two
boot-flows described above are implemented.
Simultaneously, the manifest is now read from the FDT available at
Hafnium init time. This required two notable changes:
(1) all values are copied into the manifest struct because FDT is
unmapped, modified and passed to the primary VM,
(2) manifest is now written as an overlay; QEMU and FVP test drivers
overlay it automatically.
Bug: 117551352
Change-Id: Ieae7fe4ef5b3047174ec0ad057e487660ccd5a03
diff --git a/docs/GettingStarted.md b/docs/GettingStarted.md
index dba6365..1989855 100644
--- a/docs/GettingStarted.md
+++ b/docs/GettingStarted.md
@@ -51,11 +51,32 @@
machines to run. Follow the [Hafnium RAM disk](HafniumRamDisk.md) instructions
to create an initial RAM disk for Hafnium with Linux as the primary VM.
+Next, you need to create a manifest which will describe the VM to Hafnium.
+Follow the [Manifest](Manifest.md) instructions and build a DTBO with:
+```
+/dts-v1/;
+/plugin/;
+
+&{/} {
+ hypervisor {
+ vm1 {
+ debug_name = "Linux VM";
+ };
+ };
+};
+```
+
+Dump the DTB used by QEMU:
+```shell
+qemu-system-aarch64 -M virt,gic_version=3 -cpu cortex-a57 -nographic -machine virtualization=true -kernel out/reference/qemu_aarch64_clang/hafnium.bin -initrd initrd.img -append "rdinit=/sbin/init" -machine dumpdtb=qemu.dtb
+```
+and follow instructions in [Manifest](Manifest.md) to overlay it with the manifest.
+
The following command line will run Hafnium, with the RAM disk just created,
which will then boot into the primary Linux VM:
```shell
-qemu-system-aarch64 -M virt,gic_version=3 -cpu cortex-a57 -nographic -machine virtualization=true -kernel out/reference/qemu_aarch64_clang/hafnium.bin -initrd initrd.img -append "rdinit=/sbin/init"
+qemu-system-aarch64 -M virt,gic_version=3 -cpu cortex-a57 -nographic -machine virtualization=true -kernel out/reference/qemu_aarch64_clang/hafnium.bin -initrd initrd.img -append "rdinit=/sbin/init" -dtb=qemu_with_manifest.dtb
```
## Running tests