Embedded Tinkerer Sandbox
This is a basic embedded software sandbox that can be used to experiment with some of the essential open source components used in low-level development. Generating production quality software BSP images is NOT a goal here. Gaining some understanding of how things are really built, or can be built, is the purpose behind the work. It is used to evaluate upstream changes to toolchain components, Linux, U-Boot, and Buildroot. Being close to upstream development helps with the task of contributing back to those projects. As the name suggests, this is about tinkering.
- am335x-pocketbeagle [Octavo/TI Arm Cortex-A8]
- am3517-evm [TI Arm Cortex-A8]
- aml-s905x-cc [Amlogic Arm Cortex-A53]
- ek-tm4c123gxl [TI TivaC Arm Cortex-M4]
- ek-tm4c1294xl [TI TivaC Arm Cortex-M4]
- ls1043ardb [NXP Layerscape Arm Cortex-A53]
- nrf52840-dongle [Nordic Arm Cortex-M4]
- omap3-beagle [TI Arm Cortex-A8]
- omap3-evm [TI Arm Cortex-A8]
- pynq-z2 [Xilinx Zynq-7020 Arm Cortex-A9]
- sama5d3-xpld [Arm Cortex-A5]arm-cortex
- k3-j721e-sk [TI TDA4VM Arm Cortex-R5 / Cortex-A72]
- visionfive2 [StarFive VisionFive 2 RISC-V 64-bit]
These boards are not directly built, but rather provide common SOC definitions used by higher level real boards. This tracks the Linux kernel view of what is common to a given platform. Configuration files for Linux, U-Boot, and Buildroot reside in the virtual boards.
- layerscape [ls1043ardb]
- meson [aml-s905x-cc]
- omap2plus [am335x-pocketbeagle, am3517-evm, omap3-beagle, omap3-evm]
- sama5 [sama5d3-xpld]
- zynq [pynq-z2]
- k3 [k3-j721e-sk]
- starfive [visionfive2]
These boards allow building toolchains in the same manner as a higher level board. The configuration files for crosstool-ng reside with the toolchain boards. This concept is useful for testing new and/or variant toolchains.
- aarch64-cortexa53-linux-gnu [layerscape, meson]
- aarch64-cortexa72-linux-gnu [k3]
- arm-none-eabi
- arm-none-eabihf [ek-tm4c123gxl, ek-tm4c1294xl, nrf52840-dongle, k3]
- arm-cortexr5-eabihf [k3]
- arm-cortexa5-linux-gnueabihf [sama5]
- arm-cortexa8-linux-gnueabihf [omap2plus]
- arm-cortexa9-linux-gnueabihf [zynq]
- riscv64-unknown-linux-gnu [starfive]
- Clone etinker
$ git clone https://github.com/WoodsTechnicalSolutions/etinker
- Install build dependencies (Assumes Ubuntu 22.04 LTS or newer)
$ cd etinker
$ ./scripts/host/setup
- Build your first board
$ ET_BOARD=am335x-pocketbeagle make sandbox
Depending on your workstation hardware, the build time could be 1.5 hours or greater. The GNU toolchain (C/C++ compiler, C library, and debugger) is built, from source, by crosstool-ng. This will account for at least half the build time typically. The build tools need access to a network with a route to the Internet. All of the source code will be pulled from online locations. Slow network connections will also impact build time significantly, for the first build. Repositories and tarballs are cached locally. The download time penalty is paid only at the time of initial builds and upgrades.
- Verify build artifacts
$ tree -L 2 toolchain bootloader kernel rootfs
toolchain
├── arm-cortexa8-linux-gnueabihf
│ ├── arm-cortexa8-linux-gnueabihf
│ ├── bin
│ ├── build.log.bz2
│ ├── include
│ ├── lib
│ ├── libexec
│ └── share
├── build
│ └── arm-cortexa8-linux-gnueabihf
└── generator
bootloader
├── am335x-pocketbeagle
│ └── arm-cortexa8-linux-gnueabihf
└── build
└── am335x-pocketbeagle
kernel
├── am335x-pocketbeagle
│ └── arm-cortexa8-linux-gnueabihf
└── build
└── omap2plus
rootfs
├── am335x-pocketbeagle
│ └── arm-cortexa8-linux-gnueabihf
└── build
└── omap2plus
$ tree -L 3 rootfs/am335x-pocketbeagle/
rootfs/am335x-pocketbeagle/
└── arm-cortexa8-linux-gnueabihf
└── images
└── rootfs.tar
$ du -chs etinker
84G etinker
84G total
- Format SD/MMC card
The provided mksdcard script is used to setup the 'etinker' preferred disk layout:
| Partition | Type | Size (MiB) | Label | Mount Point |
|---|---|---|---|---|
| RAW | 68 | |||
| 1 | fat32 | 550 | BOOT | /media/BOOT |
| 2 | ext4 | 4000 | rootfs | /media/rootfs |
| 3 | ext4 | remaining | data | /media/data |
Makefile tooling and scripts expect this arrangement.
$ sudo ./scripts/mksdcard am335x-pocketbeagle /dev/sdX
The /dev/sdX depends on the media that you have chosen. It can be an MMC block device also. ( i.e. /dev/mmcblkXpY) The resultant SD/MMC will have four partitions. [16 GiB SD/MMC used as example] NOTE: Use higher quality SD/MMC cards (Class 10, UHS-1 or better)
$ sudo parted --list
[...]
Model: Generic MassStorageClass (scsi)
Disk /dev/sdX: 16.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size File system Name Flags
1 71.3MB 648MB 577MB fat32 primary boot, lba
2 648MB 4842MB 4194MB ext4 primary
3 4842MB 16.0GB 11.1GB ext4 primary
[...]
You should properly unmount and eject the SD/MMC card and re-insert to verify partitions were created correctly. You will need to mount each partition in the '/media' directory. The disk partitions can be found using the 'ls -l /dev/disk/by-label' command.
$ df
Filesystem 1K-blocks Used Available Use% Mounted on
[...]
/dev/sdX1 562080 4 562076 1% /media/BOOT
/dev/sdX2 3950176 24 3892808 1% /media/rootfs
/dev/sdX3 10596592 24 10471448 1% /media/data
[...]
- Setup SD/MMC card for booting
The media is expected to be partitioned, formatted, and have '/media/BOOT', '/media/rootfs', and '/media/data' as the mount points. The following make commands will populate the media:
$ ET_BOARD=am335x-pocketbeagle make rootfs-sync-mmc
$ ET_BOARD=am335x-pocketbeagle make bootloader-sync-mmc
$ ET_BOARD=am335x-pocketbeagle make kernel-sync-mmc
$ ET_BOARD=am335x-pocketbeagle make overlay-sync-mmc
OR simply
$ ET_BOARD=am335x-pocketbeagle make sync
Each make command, shown above, results in a 'sync' of the fileystem. So it may take a minute or two to complete, depending on file sizes.
Your SD/MMC card is now ready to boot your board. Enjoy.