feat: Add Centauri Carbon 2 support and update build documentation

Development.md

@@ -1,8 +1,9 @@
-# Elegoo Centauri Carbon 1 - Yocto Firmware Build
+# Elegoo Centauri Carbon - Yocto Firmware Build
 
-This repository contains a Yocto Project-based firmware build system for the Elegoo Centauri Carbon 1 3D printer. The mainboard of this printer is powered by an Allwinner r528 SoC.
+This repository contains a Yocto Project-based firmware build system for the Elegoo Centauri Carbon 3D printer family. The mainboard of these printers is powered by an Allwinner R528 SoC.
 
 _**Unsure about what COSMOS is? [Check the FAQ to learn more](./FAQ.md)**_
+
 ## Prerequisites
 
 Before starting the build process, you need to install the required dependencies on your host system (Ubuntu/Debian is assumed):
@@ -16,6 +17,67 @@ sudo apt install gawk wget git diffstat unzip texinfo gcc build-essential \
      bmap-tools sunxi-tools
 ```
 
+## Build Configuration Options
+
+### Machine Selection (CC1 vs CC2)
+
+The build supports different machine configurations for the Centauri Carbon variants:
+
+| Machine | Description |
+|---------|-------------|
+| `elegoo-centauri-carbon1` | Original Centauri Carbon 1 (default) |
+| `elegoo-centauri-carbon2` | Centauri Carbon 2 |
+
+The default in `build/conf/local.conf` is set to CC1:
+```bash
+MACHINE ?= "elegoo-centauri-carbon1"
+```
+
+To build for CC2, specify the machine on the command line:
+```bash
+MACHINE=elegoo-centauri-carbon2 bitbake opencentauri-image-usb
+```
+
+### Image Type Selection (USB vs eMMC)
+
+Choose the appropriate image type based on your target boot media:
+
+| Image Recipe | Target Media | Use Case |
+|--------------|--------------|----------|
+| `opencentauri-image-usb` | USB drive | Development, testing, or running from USB |
+| `opencentauri-image-mmc` | Internal eMMC | Production installation on printer internal storage |
+
+#### USB Image (`opencentauri-image-usb`)
+- Boots from USB drive
+- Read-write root filesystem
+- Suitable for development and testing
+- Larger partition layout for USB storage
+
+**Important U-Boot Configuration for USB Builds:**
+When building the USB image, the MMC environment storage options must be removed from the U-Boot defconfig for your target machine. These settings cause U-Boot to store its environment on the internal eMMC, which conflicts with USB boot.
+
+For **CC1**, edit:
+- `meta-opencentauri/recipes-bsp/u-boot/files/elegoo-centauri-carbon1/elegoo_centauri_carbon_defconfig`
+
+For **CC2**, edit:
+- `meta-opencentauri/recipes-bsp/u-boot/files/elegoo-centauri-carbon2/elegoo_centauri_carbon_defconfig`
+
+Remove (or ensure absent) these configuration options:
+```
+CONFIG_ENV_IS_IN_MMC=y
+CONFIG_ENV_OFFSET=0x1A66000
+CONFIG_ENV_OFFSET_REDUND=0x1AA5000
+CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
+```
+
+This is required for proper USB boot functionality.
+
+#### eMMC Image (`opencentauri-image-mmc`)
+- Installs to internal eMMC storage
+- Read-only SquashFS root with overlay filesystem for `/etc` on `/data` partition
+- Optimized for production use
+- Includes A/B boot partition scheme for safe updates via swupdate
+
 ## How to Build
 
 1. **Initialize the build environment:**
@@ -24,25 +86,59 @@ sudo apt install gawk wget git diffstat unzip texinfo gcc build-essential \
    source poky/oe-init-build-env build
    ```
 
-2. **Run BitBake:**
-   Once the environment is set up, you can start the build process for the target image. The primary image recipe for this project is `opencentauri-image`.
+2. **Configure your target (if needed):**
+   Ensure `MACHINE` is set correctly in `build/conf/local.conf`:
+   ```bash
+   # For CC1 or CC2
+   MACHINE ?= "elegoo-centauri-carbon1"
+   ```
+
+3. **Run BitBake:**
+   Choose the appropriate image recipe for your target:
+
+   **For USB booting:**
+   ```bash
+   bitbake opencentauri-image-usb
+   ```
+
+   **For eMMC/internal storage:**
    ```bash
-   bitbake opencentauri-image
+   bitbake opencentauri-image-mmc
    ```
+
    *Note: The first build will take a significant amount of time as it downloads and compiles all necessary packages from source.*
 
+## Build Outputs
+
+After a successful build, the output files are located in:
+
+```
+tmp/deploy/images/elegoo-centauri-carbon1/
+```
+
+### USB Image Outputs
+- `opencentauri-image-usb-elegoo-centauri-carbon1.rootfs.wic.gz` - Compressed disk image for USB drives
+
+### eMMC Image Outputs
+- `opencentauri-image-mmc-elegoo-centauri-carbon1.rootfs.wic.gz` - Full disk image for eMMC
+- `bootA.img` - Extracted boot partition image (for swupdate)
+- `bootlogos.img` - Extracted boot logos partition image (for swupdate)
+- `rootfs.squashfs` - SquashFS root filesystem
+
 ## Disk Space Requirements
 
 Building a complete Yocto image requires a substantial amount of disk space. Based on current build sizes, you should expect the project directory (including downloaded sources, build artifacts, and caches) to use approximately **38GB to 40GB** of disk space. Please ensure you have adequate free space before starting the build.
 
 ## Running on the Centauri Carbon 1
 
+### USB Boot Method (Development)
+
 Note that the current install requires having a serial UART connected to the CC1 motherboard, as well as a FEL USB cable attached. This will prevent the toolhead from being plugged in!
 
 1. **Install built firmware image to a USB drive.**
    *(Warning: This is a destructive operation! Replace `sdX` with your actual USB drive device like `sdb`, `sdc`, etc.)*
    ```bash
-   sudo bmaptool copy tmp/deploy/images/elegoo-centauri-carbon1/opencentauri-image-elegoo-centauri-carbon1.rootfs.wic.gz /dev/sdX
+   sudo bmaptool copy tmp/deploy/images/elegoo-centauri-carbon1/opencentauri-image-usb-elegoo-centauri-carbon1.rootfs.wic.gz /dev/sdX
    ```
 
 2. **Boot into FEL Mode.**
@@ -76,10 +172,40 @@ Note that the current install requires having a serial UART connected to the CC1
 5. **Access the Printer Interface.**
    Find the printer's IP address by running `ip a`. Access the Mainsail interface by visiting the printer's IP address via HTTP (port 80) in your web browser!
 
+### eMMC Install Method (Production)
+
+For installing to internal eMMC storage, use the swupdate-based installation:
+
+1. Build the `opencentauri-upgrade` target. This recipe depends on `opencentauri-image-mmc` and produces the SWUpdate bundle:
+   ```bash
+   bitbake opencentauri-upgrade
+   ```
+2. Locate the generated `.swu` file in `tmp/deploy/images/elegoo-centauri-carbon1/` (e.g. `opencentauri-upgrade-elegoo-centauri-carbon1.swu`).
+3. Copy the `.swu` file to a FAT32-formatted USB drive in the `install_opencentauri` folder, renaming it to `update.swu`.
+4. Insert the USB drive into the printer
+5. Import the `IMPORT_ME_DO_NOT_PRINT` file via the printer screen as you would for stock OpenCentauri
+
 ## Configuration and Services
 
 - **Klipper Configuration:** In the current build, the Klipper `printer.cfg` is located in `/etc/klipper/config/printer.cfg`.
 - **Services:** Everything is running as an `init.d` service. You can restart Klipper by running:
   ```bash
   service klipper restart
   ```
+
+## Troubleshooting Build Issues
+
+### Clean Build
+If you encounter build issues, try cleaning the specific package:
+```bash
+bitbake -c cleansstate <package-name>
+bitbake <image-target>
+```
+
+### Full Reset
+For a complete clean build (removes all build artifacts):
+```bash
+rm -rf tmp/
+source poky/oe-init-build-env build
+bitbake <image-target>
+```

meta-opencentauri/conf/machine/elegoo-centauri-carbon1.conf

@@ -6,9 +6,9 @@ require conf/machine/include/sun8i.inc
 
 DEFAULTTUNE = "cortexa7thf-neon-vfpv4"
 
-KERNEL_DEVICETREE = "allwinner/elegoo-centauri-carbon1.dtb"
+KERNEL_DEVICETREE = "allwinner/elegoo-centauri-carbon.dtb"
 KERNEL_IMAGETYPE = "zImage"
 UBOOT_ENTRYPOINT = "0x43000000"
 SERIAL_CONSOLES = "115200;ttyS0"
 
-UBOOT_MACHINE = "elegoo_centauri_carbon1_defconfig"
+UBOOT_MACHINE = "elegoo_centauri_carbon_defconfig"

meta-opencentauri/conf/machine/elegoo-centauri-carbon2.conf

@@ -0,0 +1,14 @@
+#@TYPE: Machine
+#@NAME: Elegoo Centauri Carbon 2
+#@DESCRIPTION: Machine configuration for the Elegoo Centauri Carbon 2, based on the Allwinner R528 CPU
+
+require conf/machine/include/sun8i.inc
+
+DEFAULTTUNE = "cortexa7thf-neon-vfpv4"
+
+KERNEL_DEVICETREE = "allwinner/elegoo-centauri-carbon.dtb"
+KERNEL_IMAGETYPE = "zImage"
+UBOOT_ENTRYPOINT = "0x43000000"
+SERIAL_CONSOLES = "115200;ttyS2"
+
+UBOOT_MACHINE = "elegoo_centauri_carbon_defconfig"

meta-opencentauri/images/files/sw-description

@@ -67,7 +67,7 @@ software =
                 },
                 {
                     name = "bootcmd_mainline";
-                    value = "run setargs_mainline; fatload mmc 0:${boot_part} 43000000 zImage; fatload mmc 0:${boot_part} 43800000 elegoo-centauri-carbon1.dtb; bootz 43000000 - 43800000";
+                    value = "run setargs_mainline; fatload mmc 0:${boot_part} 43000000 zImage; fatload mmc 0:${boot_part} 43800000 elegoo-centauri-carbon.dtb; bootz 43000000 - 43800000";
                 },
                 {
                     name = "bootcmd";
@@ -152,7 +152,7 @@ software =
                 },
                 {
                     name = "bootcmd_mainline";
-                    value = "run setargs_mainline; fatload mmc 0:${boot_part} 43000000 zImage; fatload mmc 0:${boot_part} 43800000 elegoo-centauri-carbon1.dtb; bootz 43000000 - 43800000";
+                    value = "run setargs_mainline; fatload mmc 0:${boot_part} 43000000 zImage; fatload mmc 0:${boot_part} 43800000 elegoo-centauri-carbon.dtb; bootz 43000000 - 43800000";
                 },
                 {
                     name = "bootcmd";

meta-opencentauri/images/opencentauri-image-base.bb

@@ -14,7 +14,6 @@ CORE_IMAGE_EXTRA_INSTALL += "\
     libgpiod \
     libgpiod-tools \
     kernel-modules \
-    rtw88 \
     wpa-supplicant \
     iw \
     kalico \
@@ -43,6 +42,10 @@ CORE_IMAGE_EXTRA_INSTALL += "\
     v4l-utils \
 "
 
+CORE_IMAGE_EXTRA_INSTALL:append:elegoo-centauri-carbon1 = " \
+    rtw88 \
+"
+
 INITRAMFS_IMAGE = "core-image-tiny-initramfs"
 INITRAMFS_FSTYPES = "cpio.gz"
 INITRAMFS_IMAGE_BUNDLE = "1"

meta-opencentauri/recipes-bsp/u-boot/files/0001-Add-elegoo-centauri-carbon1.dts.patch → meta-opencentauri/recipes-bsp/u-boot/files/0001-Add-elegoo-centauri-carbon.dts.patch

@@ -1,7 +1,7 @@
 From 618c5a97497dd5934dc5e8a5b6861bdaa6af5916 Mon Sep 17 00:00:00 2001
 From: James Turton <james.turton@gmx.com>
 Date: Mon, 16 Feb 2026 21:36:45 +0100
-Subject: [PATCH] Add elegoo-centauri-carbon1.dts
+Subject: [PATCH] Add elegoo-centauri-carbon.dts
 
 Signed-off-by: James Turton <james.turton@gmx.com>
 Upstream-Status: Pending [Not submitted to upstream yet]
@@ -17,7 +17,7 @@ index 04b9863b5d5..b28ed796445 100644
  	sun8i-v3-sl631-imx179.dtb \
  	sun8i-v3s-licheepi-zero.dtb
  dtb-$(CONFIG_MACH_SUN8I_R528) += \
-+	elegoo-centauri-carbon1.dtb \
++	elegoo-centauri-carbon.dtb \
  	sun8i-t113s-mangopi-mq-r-t113.dtb
  dtb-$(CONFIG_MACH_SUN50I_H5) += \
  	sun50i-h5-bananapi-m2-plus.dtb \

meta-opencentauri/recipes-bsp/u-boot/files/elegoo-centauri-carbon1.env → meta-opencentauri/recipes-bsp/u-boot/files/elegoo-centauri-carbon1/elegoo-centauri-carbon.env

@@ -4,5 +4,5 @@ systemAB_next=A
 boot_part=4
 mmc_root=/dev/mmcblk0p5
 setargs_mainline=setenv bootargs console=ttyS0,115200 earlycon=uart8250,mmio32,0x02500000 root=${mmc_root} rootwait
-bootcmd_mainline=run setargs_mainline; fatload mmc 0:${boot_part} 43000000 zImage; fatload mmc 0:${boot_part} 43800000 elegoo-centauri-carbon1.dtb; bootz 43000000 - 43800000
+bootcmd_mainline=run setargs_mainline; fatload mmc 0:${boot_part} 43000000 zImage; fatload mmc 0:${boot_part} 43800000 elegoo-centauri-carbon.dtb; bootz 43000000 - 43800000
 bootcmd=if test x${swu_mode} = xmainline; then run bootcmd_mainline; else run bootcmd_stock; fi

meta-opencentauri/recipes-bsp/u-boot/files/elegoo_centauri_carbon1_defconfig → meta-opencentauri/recipes-bsp/u-boot/files/elegoo-centauri-carbon1/elegoo_centauri_carbon_defconfig

@@ -1,6 +1,6 @@
 CONFIG_ARM=y
 CONFIG_ARCH_SUNXI=y
-CONFIG_DEFAULT_DEVICE_TREE="elegoo-centauri-carbon1"
+CONFIG_DEFAULT_DEVICE_TREE="elegoo-centauri-carbon"
 CONFIG_SPL=y
 CONFIG_MACH_SUN8I_R528=y
 CONFIG_DRAM_CLK=792
@@ -28,7 +28,7 @@ CONFIG_CMD_USB=y
 # CONFIG_USE_BOOTARGS=y
 # CONFIG_BOOTARGS="console=ttyS0,115200 earlycon=uart8250,mmio32,0x02500000 root=/dev/sda2 rootwait"
 # CONFIG_USE_BOOTCOMMAND=y
-# CONFIG_BOOTCOMMAND="fatload usb 0:1 43000000 zImage; fatload usb 0:1 43800000 elegoo-centauri-carbon1.dtb; bootz 43000000 - 43800000"
+# CONFIG_BOOTCOMMAND="fatload usb 0:1 43000000 zImage; fatload usb 0:1 43800000 elegoo-centauri-carbon.dtb; bootz 43000000 - 43800000"
 
 # Display / splash screen
 CONFIG_VIDEO=y
@@ -52,7 +52,7 @@ CONFIG_SPL_LOG_MAX_LEVEL=7
 CONFIG_SPL_LOG_CONSOLE=y
 CONFIG_SPL_STACK_R_ADDR=0x47e00000
 
-CONFIG_ENV_SOURCE_FILE="elegoo-centauri-carbon1"
+CONFIG_ENV_SOURCE_FILE="elegoo-centauri-carbon"
 CONFIG_ENV_SIZE=0x20000
 CONFIG_ENV_OFFSET=0x1A66000
 CONFIG_ENV_OFFSET_REDUND=0x1AA5000