SebastienSz: /* Boot1 partition layout */

2026-01-30T14:24:48Z

Boot1 partition layout

← Older revision		Revision as of 16:24, 30 January 2026
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	\|----------------		\|----------------
	\| style="width:50px;background:orange;color:white;" align="center" \| U-Boot env		\| style="width:50px;background:orange;color:white;" align="center" \| U-Boot env
	~~\| style="width:100px;background:white;color:black;" align="center" \| ...~~
	\| style="width:50px;background:orange;color:white;" align="center" \| U-Boot redundant env		\| style="width:50px;background:orange;color:white;" align="center" \| U-Boot redundant env
	\| style="width:~~100px~~;background:white;color:black;" align="center" \| ...		\| style="width:200px;background:white;color:black;" align="center" \| ...
	\|}		\|}

SebastienSz: /* Boot0 partition layout */

2026-01-30T14:23:37Z

Boot0 partition layout

← Older revision		Revision as of 16:23, 30 January 2026
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	{\| border="1" cellpadding="10" cellspacing="0" summary="OPOS93 eMMC partitions"		{\| border="1" cellpadding="10" cellspacing="0" summary="OPOS93 eMMC partitions"
	\|----------------		\|----------------
	\| style="width:~~10px;background:white;color:black;" align="center" \| ...~~		\| style="width:150px;background:orange;color:white;" align="center" \| opos93-u-boot.bin
	~~\| style="width:40px~~;background:orange;color:white;" align="center" \| ~~SPL~~		\| style="width:300px;background:white;color:black;" align="center" \| ...
	~~\| style="width:100px;background:white;color:black;" align="center" \| ..~~.
	\| style="width:~~150px;background:orange;color:white;" align="center" \| IMG~~
	~~\| style="width:150px~~;background:white;color:black;" align="center" \| ...
	\|}		\|}

SebastienSz: Created page with "Category: eMMC = OPOS93 eMMC layout = By default, the 8GB eMMC on OPOS93 module has 4 physical/hardware partitions: {| border="1" cellpadding="10" cellspacing="0" summary="OPOS93 eMMC partitions" |---------------- | style="width:80px;background:orange;" align="center" | Boot0 | style="width:80px;background:orange;" align="center" | Boot1 | style="background:red;" | RPMB | style="width:500px;background:green;color:white;" align="center" | User Data |} {| bord..."

2026-01-30T14:19:17Z

Created page with "Category: eMMC = OPOS93 eMMC layout = By default, the 8GB eMMC on OPOS93 module has 4 physical/hardware partitions: {| border="1" cellpadding="10" cellspacing="0" summary="OPOS93 eMMC partitions" |---------------- | style="width:80px;background:orange;" align="center" | Boot0 | style="width:80px;background:orange;" align="center" | Boot1 | style="background:red;" | RPMB | style="width:500px;background:green;color:white;" align="center" | User Data |} {| bord..."

New page

[[Category: eMMC]]

= OPOS93 eMMC layout =

By default, the 8GB eMMC on [[OPOS93]] module has 4 physical/hardware partitions:

{| border="1" cellpadding="10" cellspacing="0" summary="OPOS93 eMMC partitions"
|----------------
| style="width:80px;background:orange;" align="center" | Boot0
| style="width:80px;background:orange;" align="center" | Boot1
| style="background:red;" | RPMB
| style="width:500px;background:green;color:white;" align="center" | User Data
|}

{| border="1" cellpadding="5" cellspacing="0" summary="OPOS93 eMMC partitions details"
|- style="background:#efefef;" align="center"
!Name || U-Boot name || Size || Comment
|----------------
|boot0 || mmc dev 0 1 || 4 MBytes || U-Boot is installed on this partition
|----------------
|boot1 || mmc dev 0 2 || 4 MBytes || U-Boot env is installed on this partition
|----------------
|rpmb || mmc dev 0 3 || 4 MBytes || Not used
|----------------
|User Data || mmc dev 0 0 || remaining space (~7,3 GBytes) || Kernel, device tree and rootfs
|----------------
|}

== Boot0 partition layout ==
{| border="1" cellpadding="10" cellspacing="0" summary="OPOS93 eMMC partitions"
|----------------
| style="width:10px;background:white;color:black;" align="center" | ...
| style="width:40px;background:orange;color:white;" align="center" | SPL
| style="width:100px;background:white;color:black;" align="center" | ...
| style="width:150px;background:orange;color:white;" align="center" | IMG
| style="width:150px;background:white;color:black;" align="center" | ...
|}

* Linux device: ''/dev/mmcblk0boot0''
{| border="1" cellpadding="5" cellspacing="0" summary="Boot0 partition detail"
|- style="background:#efefef;" align="center"
! Offset (blocks) || Offset (bytes) || Size (bytes) || Comment
|----------------
|0 || 0 || 1.3 MiB || Boot image (opos93-u-boot.bin) containing U-Boot, ATF, etc...
|----------------
||| || || Free
|----------------
|}

== Boot1 partition layout ==
{| border="1" cellpadding="10" cellspacing="0" summary="OPOS93 eMMC partitions"
|----------------
| style="width:50px;background:orange;color:white;" align="center" | U-Boot env
| style="width:100px;background:white;color:black;" align="center" | ...
| style="width:50px;background:orange;color:white;" align="center" | U-Boot redundant env
| style="width:100px;background:white;color:black;" align="center" | ...
|}

* Linux device: ''/dev/mmcblk0boot1''
{| border="1" cellpadding="5" cellspacing="0" summary="Boot1 partition detail"
|- style="background:#efefef;" align="center"
! Offset (blocks) || Offset (bytes) || Size (bytes) || Comment
|----------------
|0 || 0 || 128 KiB || U-Boot environment
|----------------
|256 || 128 KiB || 128 KiB || U-Boot redundant environment
|----------------
||| || || Free
|----------------
|}

== RPMB partition layout ==
* Not used !

== User Data partition layout ==

There are 3 partitions on the "User Data" physical partition:
{| border="1" cellpadding="10" cellspacing="0" summary="OPOS93 eMMC partitions"
|----------------
| style="width:50px;background:white;color:black;" align="center" | ...
| style="width:200px;background:green;color:white;" align="center" | Failsafe/Update (primary)
| style="width:200px;background:green;color:white;" align="center" | Default Rootfs (primary)
| style="width:600px;background:green;color:white;" align="center" | Home/Data (primary)
|}

{| border="1" cellpadding="5" cellspacing="0" summary="OPOS93 eMMC User data partitions details"
|- style="background:#efefef;" align="center"
!Name || U-Boot device || Linux device || Offset (bytes) || Offset (sectors/blocs) || Size || Comment
|----------------
|MBR || NA || NA || 0 || 0 || 512 bytes (1 block) || Master Boot Record + some spare space ( -> Don't touch it :-) )
|----------------
|Failsafe || mmc 0:1 || /dev/mmcblk0p1 || 1M || 2048 (0x800) || 512 MBytes (1048576 sectors) || system/rootfs to restore your board in case of problem or setup a safe update mechanism (ext4 formatted)
|----------------
|Rootfs || mmc 0:2 || /dev/mmcblk0p2 || || 1050624 (0x10800) || 512 MBytes (1048576 sectors) || the default booted rootfs is on this partition (ext4 formatted)
|----------------
|Home/Data || mmc 0:3 || /dev/mmcblk0p3 || || 2099200 (0x200800) || Rest of space: ~6,3 GBytes (13208542 sectors) || 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:
<pre class="apf">
# resize2fs /dev/mmcblk0p2 # for Rootfs
</pre>

* Or with ''apf-config'' command:
<pre class="apf">
# apf-config
</pre>
* In menu:
<pre class="config">
| 1 Expand Filesystem(s) OS can then use all eMMC/SD space |
</pre>

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

==Tips==
* Commands to partition ''User Data'' from fdisk on Host PC with [[U-Boot UMS on APF & OPOS|U-Boot UMS]]. '''Check /dev/sdc is the eMMC of your OPOS93 device otherwise you may destroy your PC partition table !!!''':
<pre class=host>
$ sudo echo -e 'size=512MiB,type=0x83\nsize=512MiB,type=0x83\ntype=0x83' | sfdisk /dev/sdc

$ sudo mkfs.ext4 -O ^64bit,^metadata_csum,uninit_bg /dev/sdc1
$ sudo mkfs.ext4 -O ^64bit,^metadata_csum,uninit_bg /dev/sdc2
$ sudo mkfs.ext4 -O ^64bit,^metadata_csum,uninit_bg /dev/sdc3

</pre>

==Links==
* [http://fr.slideshare.net/linaroorg/intro-to-emmc http://fr.slideshare.net/linaroorg/intro-to-emmc]
* https://fr.wikipedia.org/wiki/Master_boot_record ou http://poloastucien.free.fr/mbr_fat_secteurs_boot_h.html

EMMC OPOS93 - Revision history

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