bpi-r3: Document eMMC flashing and booting with Infix

Author: mattiaswal

board/aarch64/bananapi-bpi-r3/README.md

@@ -22,6 +22,76 @@ The board comes preconfigured with:
 - SFP ports for high-speed fiber connections
 - Dual WiFi interfaces for wireless connectivity
 
+### Installing Infix on eMMC
+
+> [!IMPORTANT]
+> No standard eMMC image exist yet, you have to create it your own
+> from the SD card image by replacing fip.bin in the SD card image to
+> the eMMC variant.
+
+This guide describes how to install Infix on the internal eMMC storage of your BPI-R3.
+The installation process requires a FTDI cable for console access, SD
+card with Infix, a USB drive with the necessary bootloaders and eMMC
+system image, and involves configuring the board's boot switches.
+
+#### Required files
+
+Download the following files and place them on a FAT32-formatted USB drive:
+
+1. **NAND bootloader files** (for initial setup):
+   - [bpi-r3_spim-nand_bl2.img](https://github.com/frank-w/u-boot/releases/download/CI-BUILD-2025-10-bpi-2025.10-2025-10-13_1032/bpi-r3_spim-nand_bl2.img)
+   - [bpi-r3_spim-nand_fip.bin](https://github.com/frank-w/u-boot/releases/download/CI-BUILD-2025-10-bpi-2025.10-2025-10-13_1032/bpi-r3_spim-nand_fip.bin)
+
+2. **eMMC bootloader files**:
+   - Download and extract [bpi-r3-emmc-boot-2025.01-latest.tar.gz](https://github.com/kernelkit/infix/releases/download/latest-boot/bpi-r3-emmc-boot-2025.01-latest.tar.gz)
+   - This contains `bl2.img` and `fip.bin` for eMMC boot
+
+3. **System image**:
+   - `infix-bpi-r3-emmc.img` - The Infix system image for eMMC
+
+#### Installation steps
+
+**Step 1: Flash NAND bootloader**
+
+Boot from SD card and break into U-Boot by pressing Ctrl-C during startup:
+
+```
+usb start
+mtd erase spi-nand0
+fatload usb 0:1 0x50000000 bpi-r3_spim-nand_bl2.img
+mtd write spi-nand0 0x50000000 0x0 0x100000
+fatload usb 0:1 0x50000000 bpi-r3_spim-nand_fip.bin
+mtd write spi-nand0 0x50000000 0x380000 0x200000
+```
+
+Power off the board and set the boot switch to **0101** (NAND boot mode), then power on.
+
+**Step 2: Flash system to eMMC**
+
+From the U-Boot prompt:
+
+```
+usb start
+fatload usb 0:1 0x50000000 infix-bpi-r3-emmc.img
+setexpr blocks ${filesize} / 0x200
+mmc write 0x50000000 0x0 ${blocks}
+```
+
+**Step 3: Configure eMMC bootloader**
+
+Write the eMMC bootloader and configure the boot partition:
+
+```
+mmc partconf 0 1 1 1
+mmc erase 0x0 0x400
+fatload usb 0:1 0x50000000 bl2.img
+mmc write 0x50000000 0x0 0x400
+mmc partconf 0 1 1 0
+mmc bootbus 0 0 0 0
+```
+
+Power off the board, set the boot switch to **0110** (eMMC boot mode), and power on.
+Your BPI-R3 should now boot Infix from the internal eMMC storage.
+
 ### Pre-built images
 SD card image: [infix-bpi-r3-sdcard.img](https://github.com/kernelkit/infix/releases/download/latest-boot/infix-bpi-r3-sdcard.img)
-

doc/ChangeLog.md

@@ -24,6 +24,7 @@ All notable changes to the project are documented in this file.
   VXLAN tunnels.  This also changes the default TTL of tunnels to 64, from the
   kernel default (*inherit*), which in turn fixes reported issues with dropped
   OSPF Hello frames in GRE tunnels
+- [Document][bpi-r3-emmc-documentation] how to go from SD card to eMMC on bpi-r3
 
 ### Fixes
 
@@ -32,6 +33,7 @@ All notable changes to the project are documented in this file.
   boot step "Mounting filesystems ..." with up to 30 seconds!
 
 [lastest-boot]: https://github.com/kernelkit/infix/releases/latest-boot
+[bpi-r3-emmc-documentation]: https://github.com/kernelkit/infix/blob/main/board/aarch64/bananapi-bpi-r3/README.md
 
 [v25.10.0][] - 2025-10-31
 -------------------------