eMMC Partition Customization on Astra Machina
The main internal storage used for Astra Machina is the eMMC chip located on the Core Module. The eMMC has partitions for firmware, the root fs, and a home partition. These partitions can be resized to allow more data to be stored in a specific partition. The most common use case would be to enlarge the root fs to accommodate more packages being installed on the board.
Partition Size |
Partition Name |
Erase / Format |
First Action |
Write Protection |
|---|---|---|---|---|
factory_setting |
format |
default |
none |
|
1M |
key_a |
default |
default |
none |
7M |
tzk_a |
default |
default |
none |
1M |
key_b |
default |
default |
none |
7M |
tzk_b |
default |
default |
none |
16M |
bl_a |
default |
default |
none |
16M |
bl_b |
default |
default |
none |
32M |
boot_a |
default |
default |
none |
32M |
boot_b |
default |
default |
none |
32M |
firmware_a |
default |
default |
none |
32M |
firmware_b |
default |
default |
none |
1408M |
rootfs_a |
default |
default |
none |
1408M |
rootfs_b |
default |
default |
none |
16M |
fastlogo_a |
default |
default |
none |
16M |
fastlogo_b |
default |
default |
none |
2M |
devinfo |
erase |
default |
none |
2M |
misc |
erase |
default |
none |
home |
default |
default |
none |
The default image layout for SL1620, SL1640, and SL1680. As of v1.2.0, the home partition is resized to the use the remaining space left at the end of the eMMC.
Some partitions have a and b versions. These redundant partitions are used to support system update.
Note
Enlarging an ab partition will require 2x additional space on the eMMC.
Changing Partition Sizes
The eMMC partition layout is set in the emmc.pt file included in the synasdk-config-native package. Use the devtool utility to
modify the config file:
devtool modify synasdk-config-native
The devtool utility will create the build-sl1680/workspace/sources/synasdk-config-native/configs/product directory which will contain the source for
the config package. In the product directory is a subdirectory containing a config file for each of the platforms. Edit the emmc.pt file for the platform which
you are building for.
For example, to change the root fs partition size for SL1680, edit sl1680_poky_aarch64_rdk/emmc.pt.
Change made to double the root fs partition on SL1680
Enlarging the Total eMMC Size
The default eMMC image size is 16GB. This is the minimum eMMC size for Astra Machina Core Modules. If you have a device with a larger eMMC and would like to allocate more space to system partitions, then you can enlarge the total eMMC size to accommodate the larger partitions.
The total eMMC size is set in the in the configuration file included in the synasdk-config-native package. Set the CONFIG_EMMC_TOTAL_SIZE parameter
to the to the total size of the eMMC on your board.
Setting the total eMMC size to 32GB on SL1680
Building the Updated Image
Finally, build an image with the modified eMMC partition layout:
devtool build synasdk-config-native
devtool build-image astra-media