TMDS64GPEVM: [Yocto] How boot image from NOR Flash?

Hi Jakub,

there's a couple of ways to do that but I assume you'd want persistent storage, right? If so this usually involves the use of a flash file system like UBIFS or JFFS2. One existing resource that comes to mind is this, can you please have a look: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1018036/am6442-how-to-create-ospi-rootfs-ubifs-and-boot-linux-from-ospi-without-sd

Let us know if there are any questions/clarification we can provide.

Thanks, Andreas

Hello Andreas

Thanks for response. So I created .ubifs image using Yocto. As far I understand this image contains all necessary objects such as Image, device tree and file system. I created it by adding this line to my yocto image recipe:

IMAGE_FSTYPES += " ubifs"

Next in U-Boot prompt I executed those commands

=> sf probe
=> tftp ${loadaddr} tiboot3.bin
=> sf update $loadaddr 0x0 $filesize
=> tftp ${loadaddr} tispl.bin
=> sf update $loadaddr 0x100000 $filesize
=> tftp ${loadaddr} u-boot.img
=> sf update $loadaddr 0x300000 $filesize

and finally load my image:

tftp ${loadaddr} texas-image.rootfs.ubifs

sf update $loadaddr 0x800000 $filesize

Then run U-Boot from NOR memory and in command prompt set:

setenv bootargs console=${console} ${optargs} root=ubi0:rootfs rw ubi.mtd=ospi.rootfs rootfstype=ubifs rootwait=1

Now I belive that I need to load kernel and device tree to RAM but I don't know exact addresses of partitions in NOR memory where resides kernel code, device tree. I don't now how Yocto prepared this image. Do you know how can I extract those informations from generated ubifs image? Or maybe my approach is completely wrong?
sf probe; sf read ${kernel_addr_r} 0x800000 <???>; sf read ${fdtaddr} <???> <???>; run run_kern

Hello Jakub,
Referring to Andreas's reply, you may want to refer to the following portion of the referenced e2e post:
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1018036/am6442-how-to-create-ospi-rootfs-ubifs-and-boot-linux-from-ospi-without-sd/3769546#3769546
"I'm able to have full OSPI boot on AM64x EVM using SDK 7.3.1, and summarizing the steps for your reference:
1. Re-partition OSPI MTD partitions
There are 7 partitions in kernel in SDK 7.3.1 as listed below:
...
I re-partition OSPI by modifying "mtdparts" bootargs as listed below:
...
Where the two additional fixed partitions are added for "ospi.dtb" and "ospi.kernel". Refer to the attached log file "am6_mtdinfo_ospi.txt" for more details.
By doing so, it is possible to load the kernel/dtb to DDR from OSPI using "sf..." cmd @u-boot instead of accessing them from "ospi.rootfs" under UBI.
...

2. Generate UBIFS/UBI rootfs files......"

Another e2e post may be helpful on customizing MTD partitions in the following e2e:
- One option to load the boot environments from OSPI instead before loading/launching kernel/dtb from the selected boot media
e2e.ti.com/.../3968228

Best,
-Hong