Revision as of 16:29, 14 September 2016

OPOS6UL eMMC layout

By default, the 4GB eMMC on OPOS6UL module has 4 physical/hardware partitions:

Boot0

Boot1

RPMB

User Data

Name	U-Boot name	Size	Comment
boot0	mmc dev 0 1	4MBytes	U-Boot is installed on this partition
boot1	mmc dev 0 2	4MBytes	Not used
rpmb	mmc dev 0 3	512KBytes	Not used
User Data	mmc dev 0 0	remaining space (~3,7GBytes)	Kernel, device tree and rootfs

.

SPL

IMG

...

ENV1

...

ENV2

...

Offset (blocks)	Offset (bytes)	Size (bytes)	Comment
0	0	1 KB (0x400)	Free
0x02	1 KB (0x400)	68 KB	U-Boot SPL (apf6-u-boot.spl)
0x8a	69 KB (0x11400)	512 KB	U-Boot IMG (apf6-u-boot.img)
			Free
0x800 (2048)	1024 KB (0x100000)	10 KB (0x2800)	U-Boot environment
			Free
0xc00 (3072)	1536 KB (0x180000)	10 KB (0x2800)	Redundant U-Boot environment
			Free

There are 3 partitions on the "User Data" physical partition:

...

Failsafe (primary)

Rootfs (logical)

Home/Data (logical)

Name	U-Boot device	Linux device	Offset (bytes)	Offset (sectors)	Size	Comment
MBR	NA	NA	0	0	512 bytes (1 block)	Master Boot Record. (Don't touch it :-) )
Failsafe	mmc 0:1	/dev/mmcblk0p1	1M	2048	64MBytes (131072 sectors)	system to restore your board in case of problem
Rootfs	mmc 0:5	/dev/mmcblk0p5		135168 (0x21000)	2GBytes (4194304 sectors)	the rootfs is on this partition (ext4 formatted)
Home/Data	mmc 0:6	/dev/mmcblk0p6		4331520 (0x421800)	Rest of space: ~1,6GBytes (3303424)	HOME can be stored on this partition (ext4 formatted)

By default, when flashed from U-Boot, rootfs and boot are only occupying the size of the .ext4 images used during flashing. If you want to increase the rootfs/boot size to all available free space then, after Linux has booted, use the following commands:

# resize2fs /dev/mmcblk0p5        # for Rootfs

# apf-config

|     1 Expand Filesystem(s)         OS can then use all eMMC/SD space         |

Rootfs/Boot will then be extended to all the "Rootfs"/"Boot" eMMC partitions space.

@@ Line 76: / Line 76: @@
 {| border="1" cellpadding="5" cellspacing="0" summary="OPOS6UL eMMC User data partitions details"
 |- style="background:#efefef;" align="center"
-!Name || U-Boot device  || Linux device || Offset (bytes) || Offset (blocks) || Size || Comment
+!Name || U-Boot device  || Linux device || Offset (bytes) || Offset (sectors) || Size || Comment
 |----------------
 |MBR || NA || NA || 0 || 0 || 512 bytes (1 block) || Master Boot Record. (Don't touch it :-) )
 |----------------
-|Failsafe || mmc 0:1 || /dev/mmcblk0p1 || 2k (0x800)|| 4 || 64MBytes || system to restore your board in case of problem
+|Failsafe || mmc 0:1 || /dev/mmcblk0p1 || 1M || 2048 || 64MBytes (131072 sectors) || system to restore your board in case of problem
 |----------------
-|Rootfs || mmc 0:5 || /dev/mmcblk0p5 ||  || 135168 (0x21000) || 2GBytes || the rootfs is on this partition (ext4 formatted)
+|Rootfs || mmc 0:5 || /dev/mmcblk0p5 ||  || 135168 (0x21000) || 2GBytes (4194304 sectors) || the rootfs is on this partition (ext4 formatted)
 |----------------
-|Home/Data || mmc 0:6 || /dev/mmcblk0p6 ||  || 4331520 (0x421800) || Rest of space (~1,6GBytes) || HOME is on this partition (ext4 formatted)
+|Home/Data || mmc 0:6 || /dev/mmcblk0p6 ||  || 4331520 (0x421800) || Rest of space: ~1,6GBytes (3303424) || HOME can be stored on this partition (ext4 formatted)
 |----------------
 |}