Boot Profiles¶

Think of Stage0 as the cursed initrd and Boot Profiles as the cursed config blob for it.

Boot Profiles describe where boot artifacts come from and how stage0 should be adjusted per image/device. Use them when a plain rootfs path/URL is not enough.

Source of Truth¶

Schema types: crates/fastboop-schema/src/lib.rs
Codec + validation: crates/fastboop-core/src/bootprofile.rs
Artifact pipeline schema/codec: gibblox-pipeline
CLI tooling: cli/src/commands/bootprofile.rs

Two Representations¶

Manifest (BootProfileManifest): YAML/JSON authoring format.
Compiled (BootProfile): binary format used by runtime commands.

fastboop boot and fastboop stage0 accept a compiled Boot Profile as the ROOTFS input.

Minimal Manifest¶

id: local-erofs
display_name: Local EROFS image

rootfs:
  erofs:
    file: ./artifacts/rootfs.ero

stage0:
  extra_modules:
    - ff-memless

Maximal Manifest (Pipeline-Heavy)¶

id: generic-edge-phone
display_name: Generic edge image

rootfs:
  ext4:
    mbr:
      index: 1
      android_sparseimg:
        xz:
          http: https://downloads.example.com/images/generic-edge.img.xz

kernel:
  path: /vmlinuz
  fat:
    mbr:
      index: 0
      android_sparseimg:
        xz:
          http: https://downloads.example.com/images/generic-edge.img.xz

dtbs:
  path: /dtbs
  fat:
    mbr:
      index: 0
      android_sparseimg:
        xz:
          http: https://downloads.example.com/images/generic-edge.img.xz

extra_cmdline: console=ttyMSM0,115200n8

Validation Highlights¶

rootfs schema supports erofs, ext4, and fat.
Stage0 lower-root currently accepts erofs and ext4; use fat for kernel/dtbs source pipelines.
Artifact pipeline validation/limits come from gibblox-pipeline (MAX_PIPELINE_DEPTH=16).
GPT/MBR selector steps must choose exactly one selector field.
kernel.path and dtbs.path (if present) must be non-empty.
dt_overlays compile/decompile requires dtc.

How To Bang On It¶

# compile manifest -> binary
cargo run -p fastboop-cli -- bootprofile create ./profile.yaml -o /tmp/profile.fbp

# compile + materialize android sparse index hints
cargo run -p fastboop-cli -- bootprofile create ./profile.yaml --optimize-pipeline-hints -o /tmp/profile.fbp

# inspect binary -> yaml
cargo run -p fastboop-cli -- bootprofile show /tmp/profile.fbp

# exercise stage0 path through compiled profile
cargo run -p fastboop-cli -- stage0 /tmp/profile.fbp --device-profile <id> > /tmp/stage0.cpio