Hi,
I think I need to make my question more clear.
My custom board has constraint that it has only 2 boot configurations.
1. Serial download over usb (to download image to eMMC)
2. Boot from eMMC
Where as my device has an SD card interface for additional memory. Please note due to the limitation of boot config ckt in my hardware the SD card cannot be made as first boot device. So I need to boot from eMMC always.
Now I am trying to boot Android 9 in my device. The minimum SDcard/eMMC image size mentioned in user guide of Android 9 is 8GB. But my eMMC has only 4GB.
So my question was that, is it possible to flash the uboot to eMMC whereas zImage and file system to SD card?
If it possible, on reset uboot in eMMC will run first and then it will launch the Kernel in SD card( which has more space store the Android Kernal and file system).
Hope I made the question clear. Thank you for the information on precautions to take while building and flashing image to eMMC. But what I would like to have is the reply for the updated query. In near future for the firmware update I want to keep A/B images of OS so I need to make use of the SD card slot due to the limited size of eMMC.
Regards,
Bijesh V.M.