tree 5ed68a1159abc203f67790b27704ed1c5adad267
parent 4a9a960aa04c518cc358d57234cd75f9b7456fb7
author Adriana Kobylak <anoo@us.ibm.com> 1585416571 -0500
committer Andrew Geissler <geissonator@yahoo.com> 1594828009 -0500

aspeed: Build a wic image for the eMMC User Data Area

The U-Boot SPL and U-Boot proper would be programmed to the
Boot Area Hardware Partitions of the eMMC. The kernel and user
space would go into the User Data Area. This commit creates an
image that can be programmed into that User Data Area. Layout:

 --- - ----- -------- -------- ----- ------- ------ -------- -------
|GPT| | env | boot-a | boot-b | fs-a | fs-b | rwfs | hostfw |GPT-sec|
 --- - ----- -------- -------- ------ ------ ------ -------- -------
      ^ 1MB    64MB     64MB    1GB     1GB    7GB     5GB
      |
      0x5000

Primary GPT size (Beginning of image):
512B (Protective MBR) + 512B (Primary Header) + 16KB (Primary Table)
First partition (u-boot-env) is 4K-aligned, which puts it at offset 0x5000

Secondary GPT size (End of image):
16KB (Secondary Table) + 512B (Secondary Header)

Since the secondary GPT is expected to be at the end of the device,
the initramfs can issue a "sgdisk -e /dev/mmcblk0" on first boot
to move it to the end.

The first partition holds the U-Boot environment. The following two
partitions hold a filesystem with the fitImage file. Code update
would reflash the full filesystem with the fitImage during an update.

U-Boot can then be programmed to look for the kernel in partitions
boot-a or boot-b.

The remaining is a set of ext4 filesystems for user space, read-write,
and host firmware.

The size for the host firmware partition is configurable to be able
to build an image of different size. The reason is that the tacoma
system is has a User Data area just 1GB smaller than rainier.

Design doc: https://gerrit.openbmc-project.xyz/c/openbmc/docs/+/28443

Tested: Adding "WKS_HOSTFW_SIZE = "4G"" to the tacoma.conf file
        created a 14GB wic file:
$ ls -lh *wic
-rw-r--r-- 1 anoo 532919 15G Jul 14 08:18 obmc-phosphor-image-rainier.wic
-rw-r--r-- 1 anoo 532919 14G Jul 14 08:36 obmc-phosphor-image-witherspoon-tacoma.wi

$ wic ls obmc-phosphor-image-rainier.wic
Num     Start        End          Size      Fstype
...
 7    9798963200  15167672319   5368709120  ext4

$ wic ls obmc-phosphor-image-witherspoon-tacoma.wic
Num     Start        End          Size      Fstype
...
 7    9798963200  14093930495   4294967296  ext4

(From meta-aspeed rev: b8a647297e3f9fe724f8ee1736bb9da3806d788e)

Change-Id: I18b8a15ac8eddb6abfbc7b70429ef45ffc170d9a
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>