linux requires EL1,however uboot is in EL3 mode.linux is halted.
Hi,
You can refer ARM Trusted Firmware (ATF). ATF is maintained under github which
includes documentation including the Firmware Design document which describes the
boot flow, and a Porting Guide which may be of use to you.
Regards,
Sudeep
is it ok without ATF ?
I mean to force uboot to EL1 from EL3.
dudu8,
U-Boot should not be attempting to boot the kernel at EL3 if you're just using commands like "bootm" or "bootz" to execute the kernel image. The answer, really, is that U-Boot should be switching from EL3 to EL1 (or EL2) automatically, for you.
Are you asking how U-Boot changes exception levels (out of curiosity) or does your U-Boot simply branch to the kernel at the current exception level? Your screenshots don't make much sense: both instructions are completely valid at EL3. Are these U-Boot "screenshots" or Linux?
What exactly is your question related to?
Ta,
Matt
The screenshots is from linux enable_mmu section.
I only just want u-boot to execute the kernel image directly.But u-boot is at EL3,however linux is at EL1.
i want to know how u-boot to enter EL1 mode directly.