Am 13.01.2023 um 15:52 schrieb Heinrich Schuchardt:
On 1/13/23 14:47, Michael Lawnick wrote:
Hi,
I am trying to printf-debug EFI execution triggered by Linux call.
Specifically I remove a persistent variable via Linux console and want
to follow execution. Without any printf() this works fine. I need this
Hello Michael,
U-Boot does not implement SetVariable() at runtime yet.
Hi Heinrich,
seems we got this by our SoC Vendor who provides us with U-Boot with EFI
support.
to refine existing implementation of saving variables to SPI flash.
While printf() works in U-Boot startup context it leads to crash when
EFI function was called from Linux. Same for putc().
Next I tried efi_st_printf() but this already crashes in U-Boot startup
context.
How do you achieve printf() debugging in this scenario?
Which initialization steps are required to get efi_st_printf() working
outside self_test context?
TIA & KR
Michael
U-Boots print functions can only be used before ExitBootServices().
Don't use any library function that is not declared __efi_runtime after
this point.
that was my problem.
At UEFI runtime you might be able to invoke a Linux syscall. I never
tried it.
Meanwhile I found out that the SPI write is moved into ATF from where I
have much less restrictions. As such my problem is solved for now.
Or move the debug output into a different UEFI variable using
* efi_var_mem_del() to delete the existing instance
* efi_var_mem_ins() to create the new instance
Both calls are needed.
Nice ugly idea :-)
THX
Michael
