WIP Add rpi02w target

README.md

@@ -35,6 +35,8 @@ Supported targets in this repository:
 
 - `grisp2`
 - `kontron-albl-imx8mm`
+- `rpi0w`
+- `rpi02w`
 
 ## Getting Started
 

Vagrantfile

@@ -282,6 +282,7 @@ Vagrant.configure('2') do |config|
     config.vm.provision 'file', source: "system_grisp2", destination: "/home/vagrant/system_grisp2"
     config.vm.provision 'file', source: "system_kontron-albl-imx8mm", destination: "/home/vagrant/system_kontron-albl-imx8mm"
     config.vm.provision 'file', source: "system_rpi0w", destination: "/home/vagrant/system_rpi0w"
+    config.vm.provision 'file', source: "system_rpi02w", destination: "/home/vagrant/system_rpi02w"
 
     config.vm.provider :vmware_desktop do |v, override|
         # On MacOS, NFS sometimes freezes, use vmware GHFS instead.

docs/README.md

@@ -13,6 +13,8 @@ repo-level [`README.md`](../README.md).
   the Vagrant wrapper fits in on non-Linux hosts.
 - [`porting-notes.md`](./porting-notes.md): short field notebook of
   traps encountered during target bring-up.
+- [`porting-notes-rpi02w.md`](./porting-notes-rpi02w.md): delta notes
+  for porting from `system_rpi0w` to `system_rpi02w`.
 
 ## Index
 
@@ -21,6 +23,7 @@ repo-level [`README.md`](../README.md).
 | `system_grisp2` | Supported | (no design doc yet) |
 | `system_kontron-albl-imx8mm` | Supported | (no design doc yet) |
 | `system_rpi0w` | In development; first-boot working, peripheral bring-up staged, A/B lifecycle not yet exercised on hardware | [`system_rpi0w.md`](./system_rpi0w.md) |
+| `system_rpi02w` | In development; initial target scaffold for Cortex-A53/ARMv8, hardware validation pending | [`system_rpi02w.md`](./system_rpi02w.md) |
 
 ## What a target design doc should cover
 

docs/porting-notes-rpi02w.md

@@ -0,0 +1,60 @@
+# `rpi02w` Porting Notes (vs `rpi0w`)
+
+This note captures what was different when bringing up `system_rpi02w`
+from the existing `system_rpi0w` target.
+
+## CPU / ABI
+
+- SoC class changes from ARMv6 to ARMv8-A (`cortex-a53`).
+- Userspace/toolchain moves from 32-bit ARM to `aarch64-unknown-linux-gnu`.
+- New toolchain defconfigs:
+  - `toolchain/configs/rpi02w_linux_x86_64_defconfig`
+  - `toolchain/configs/rpi02w_linux_aarch64_defconfig`
+
+## Kernel / Boot Artifacts
+
+- Kernel image consumed by firmware is `kernel8.img` (sourced from Buildroot `Image`).
+- DTB switches to `bcm2710-rpi-zero-2-w.dtb`.
+- `config.txt` requires 64-bit boot settings:
+  - `arm_64bit=1`
+  - `kernel=kernel8.img`
+  - explicit `start_file` / `fixup_file` selection
+- `cmdline-a.txt` / `cmdline-b.txt` map to rootfs A/B:
+  - `root=/dev/mmcblk0p5` and `root=/dev/mmcblk0p6`
+
+## Firmware Layout / fwup
+
+- `system_rpi02w/fwup_include/fwup-common.conf` intentionally mirrors
+  `system_rpi0w` partition geometry to preserve the same A/B update style:
+  - AUTOBOOT offset/count: `2048 / 32768`
+  - BOOT-A offset/count: `34816 / 65536`
+  - BOOT-B offset/count: `100352 / 65536`
+  - ROOTFS-A offset/count: `167936 / 286720`
+  - ROOTFS-B offset/count: `456704 / 286720`
+  - APP offset/count: `745472 / 1048576 (expand)`
+- `fwup.conf` keeps GRiSP A/B state semantics (`upgrade.*`, `validate.*`,
+  `rollback.*`, `status.*`) while using Pi `tryboot` behavior via
+  `autoboot.txt`.
+
+## Console / Device Bring-up
+
+- USB gadget serial remains the primary Erlang console (`ttyGS0`).
+- UART console (`ttyAMA0`) remains enabled for early boot diagnostics.
+- Bluetooth on mini-UART requires explicit kernel config enablement:
+  - `CONFIG_BT_HCIUART`, `CONFIG_BT_HCIUART_BCM`,
+    `CONFIG_BT_HCIUART_SERDEV`, `CONFIG_BT_BCM`
+  - `CONFIG_SERIAL_DEV_BUS` and `CONFIG_SERIAL_DEV_CTRL_TTYPORT`
+
+## Build / Integration Touchpoints
+
+- Add `system_rpi02w` folder and `VERSION`.
+- Add `system_rpi02w` provisioning entry in `Vagrantfile`.
+- Add `rpi02w` to supported target list in top-level `README.md`.
+- Add `system_rpi02w` docs entry in `docs/README.md`.
+
+## Observed Bring-up Pitfalls
+
+- Stale SD boot files can hide source fixes; verify BOOT-A `config.txt` and
+  `cmdline.txt` match the current repo before concluding boot regressions.
+- ACT LED heartbeat in `config.txt` can look like a fault blink pattern;
+  use UART output to classify real early-boot failures.

docs/system_rpi02w.md

@@ -0,0 +1,45 @@
+# `system_rpi02w`: Architecture Notes
+
+Design note for the Raspberry Pi Zero 2 W target.
+
+## Overview
+
+`system_rpi02w` is the Pi Zero 2 W sibling of `system_rpi0w`.
+It keeps the same GRiSP Alloy update model (`fwup` tasks + uboot-env
+schema + tryboot flow), but moves to a Cortex-A53/ARMv8 (aarch64)
+toolchain and the Zero 2 W DTB.
+
+## Key Deltas vs `system_rpi0w`
+
+- Target name: `rpi02w`
+- Toolchain tuple: `aarch64-unknown-linux-gnu`
+- Crosstool configs:
+  - `toolchain/configs/rpi02w_linux_x86_64_defconfig`
+  - `toolchain/configs/rpi02w_linux_aarch64_defconfig`
+- Buildroot arch selection in `system_rpi02w/defconfig`:
+  - `BR2_aarch64=y`
+  - `BR2_cortex_a53=y`
+- Firmware DTB payload in `system_rpi02w/fwup.conf`:
+  - `bcm2710-rpi-zero-2-w.dtb`
+- Kernel file consumed by fwup from SDK images:
+  - `${GRISP_SYSTEM}/images/Image` (packaged as `kernel8.img` in BOOT-A/B)
+
+See also:
+- [`porting-notes-rpi02w.md`](./porting-notes-rpi02w.md) for a
+  checklist-style delta from `system_rpi0w`.
+
+## Build Pipeline Usage
+
+```sh
+./build-toolchain.sh rpi02w
+./build-sdk.sh rpi02w
+./build-project.sh rpi02w <project>
+./build-firmware.sh rpi02w <artefact-prefix-or-path>
+```
+
+## Status
+
+- Integrated into repo structure and Vagrant provisioning.
+- Boot to Erlang shell confirmed on hardware.
+- Bluetooth HCI UART support requires rebuilt kernel/SDK after
+  `linux-6.12.defconfig` updates.

system_rpi02w/Config.in

@@ -0,0 +1,2 @@
+# Target-specific Buildroot options for system_rpi02w go here.
+# Sourced by system_common/Config.in via $BR2_EXTERNAL_GRISP_PATH.

system_rpi02w/README.md

@@ -0,0 +1,50 @@
+# Raspberry Pi Zero 2 W System Notes
+
+Target-specific, implementation-coupled notes for `system_rpi02w`
+(Raspberry Pi Zero 2 W: BCM2710A1 / Cortex-A53 / ARMv8).
+
+## Hardware
+
+| Property | Value |
+|---|---|
+| Board | Raspberry Pi Zero 2 W |
+| SoC | Broadcom BCM2710A1 |
+| CPU | Quad-core Cortex-A53 (ARMv8-A) |
+| RAM | 512 MiB |
+| Wi-Fi/BT | BCM43436, 802.11n + BT 4.2 |
+
+## Current Target Shape
+
+- Target name: `rpi02w`
+- System directory: `system_rpi02w/`
+- Toolchain tuple: `aarch64-unknown-linux-gnu`
+- Toolchain configs:
+  - `toolchain/configs/rpi02w_linux_x86_64_defconfig`
+  - `toolchain/configs/rpi02w_linux_aarch64_defconfig`
+- Kernel source pin: `raspberrypi/linux` tag `stable_20250916`
+- Kernel DTB staged into firmware: `bcm2710-rpi-zero-2-w.dtb`
+
+## Boot and Update Model
+
+`system_rpi02w` follows the same model as `system_rpi0w`:
+
+- No U-Boot bootloader in the boot chain.
+- VideoCore firmware + `tryboot` A/B boot selection.
+- Same GRiSP Alloy fwup task vocabulary and uboot-env schema
+  (`complete`, `upgrade.{a,b}`, `validate.{a,b}`, `rollback.{a,b}`).
+
+Key files:
+
+- `defconfig`: Buildroot target configuration.
+- `linux/linux-6.12.defconfig`: custom kernel config seed.
+- `fwup.conf`: firmware packaging and A/B task logic.
+- `config.txt`, `cmdline-*.txt`, `autoboot-*.txt`: staged boot artifacts.
+- `rootfs_overlay/etc/erlinit.config`: runtime init and console selection.
+
+## Status
+
+This is an initial target scaffold derived from `system_rpi0w` and adapted
+for the Zero 2 W architecture and DTB path.
+
+- Build integration is wired through the four-stage pipeline.
+- Hardware validation is still required (boot, Wi-Fi/BT, A/B lifecycle).

system_rpi02w/VERSION

@@ -0,0 +1 @@
+0.1.0

system_rpi02w/autoboot-a.txt

@@ -0,0 +1,6 @@
+[all]
+tryboot_a_b=1
+boot_partition=2
+
+[tryboot]
+boot_partition=3

system_rpi02w/autoboot-b.txt

@@ -0,0 +1,6 @@
+[all]
+tryboot_a_b=1
+boot_partition=3
+
+[tryboot]
+boot_partition=2

system_rpi02w/cmdline-a.txt

@@ -0,0 +1 @@
+root=/dev/mmcblk0p5 rootwait rootfstype=squashfs console=ttyAMA0,115200 console=ttyGS0

system_rpi02w/cmdline-b.txt

@@ -0,0 +1 @@
+root=/dev/mmcblk0p6 rootwait rootfstype=squashfs console=ttyAMA0,115200 console=ttyGS0

system_rpi02w/config.txt

@@ -0,0 +1,60 @@
+# Raspberry Pi Zero 2 W firmware config.
+#
+# Read by the VideoCore GPU firmware (start.elf) from the active BOOT-{A,B}
+# partition. Tells the GPU how to load the Linux kernel.
+#
+# Keep this file identical on BOOT-A and BOOT-B unless a slot-specific quirk
+# demands otherwise: fwup's complete / upgrade.* tasks write the same
+# config.txt to both partitions.
+#
+# Several values and the miniuart-bt routing trick follow
+# nerves_system_rpi0/rpi-firmware/config.txt; individual lines are marked
+# "matches nerves_system_rpi0" where the specific choice is non-obvious.
+
+# Keep the same kernel filename convention as Nerves on 64-bit Pi targets.
+kernel=kernel8.img
+arm_64bit=1
+start_file=start.elf
+fixup_file=fixup.dat
+
+disable_splash=1
+
+# Reserve 192 MiB of the 512 MiB SoC for the GPU/framebuffer; leaves ~320
+# MiB for Linux + userland. Tunable; matches nerves_system_rpi0.
+gpu_mem=192
+
+# On-board peripherals exposed to Linux.
+dtparam=i2c_arm=on
+dtparam=spi=on
+dtparam=audio=on
+
+# Enable camera auto-detection for CSI. Safe to leave on even when no camera
+# is connected; the kernel just skips it.
+camera_auto_detect=1
+display_auto_detect=1
+
+# USB OTG / gadget mode for the CDC-ACM serial console on ttyGS0, exposed
+# over the middle micro-USB port. On the host, `picocom -b 115200
+# /dev/tty.usbmodem*` (macOS) or `/dev/ttyACM0` (Linux) lands on the BEAM.
+dtoverlay=dwc2
+
+# Route Bluetooth to the mini-UART and keep PL011 (ttyAMA0) free for the
+# Linux console. Without this, console characters race BT traffic on the
+# same UART.
+enable_uart=1
+dtoverlay=miniuart-bt
+# The VPU clock must be fixed when the mini-UART shares the PLL with BT.
+core_freq=250
+
+# Heartbeat on the green ACT LED so the board shows signs of life without
+# a UART attached.
+dtparam=act_led_activelow=on
+dtparam=act_led_trigger=heartbeat
+
+# Ramoops: reserve a small RAM region for pstore so kernel oopses survive
+# a warm reboot. The upstream RPi kernel already ships overlays/ramoops.dtbo
+# (arch/arm/boot/dts/overlays/ramoops.dtbo); fwup.conf stages it onto
+# BOOT-A/B alongside dwc2 and miniuart-bt. peripherals-init.sh (run by
+# erlinit as --pre-run-exec) mounts pstore at /sys/fs/pstore so
+# `ls /sys/fs/pstore` shows the previous boot's dmesg.
+dtoverlay=ramoops

system_rpi02w/crucible.sh

@@ -0,0 +1,15 @@
+OS_RELEASE_PRETTY_NAME="GRiSP RPi Zero 2 W"
+
+BOOTSCHEME=NONE
+
+SQUASHFS_PRIORITIES=(
+    "sbin/init" 32762
+    "etc/erlinit.config" 32761
+)
+
+FWUP_IMAGE_TARGETS=(
+    "complete" ""
+)
+
+GSU_KERNEL_PATH="/boot/kernel8.img"
+GSU_PARTITIONS=""