On 15.03.23 15:17, Michael Nazzareno Trimarchi wrote: > Hi > > On Wed, Mar 15, 2023 at 3:13 PM Frieder Schrempf > <frieder.schre...@kontron.de> wrote: >> >> Hi, >> >> I'm trying to bring up a new board based on the i.MX8MP and I have an >> issue I'm hoping someone can help solving. >> >> I'm seeing failures in the early SPL code, usually in the DDR >> initialization. Often they look like: >> >> U-Boot SPL 2023.04-rc3 (Mar 07 2023 - 14:32:34 +0000) >> Training FAILED >> Failed to initialize DDR RAM! >> ### ERROR ### Please RESET the board ### >> >> But sometimes ddr_init() doesn't even return an error and only the >> get_ram_size() afterwards which tries to allocate the memory fails. >> > > In my experience you don't have space inside the cpu internal memory. It means > that you overlap some stack with the code. Change the printf means > move a bit. So you have > problem but depends what you are going to destroy
Thanks for your reply. That's exactly what I'm thinking, too. > >> The strange thing is that the issues appear or disappear >> deterministically on the binary level. This means I sometimes get a >> U-Boot binary which runs just fine in 100% of cases. Then I change for >> example one of the following: >> >> * Adding a single printf() somewhere in the boards spl.c >> * Using the same binary but booting from SD card instead of USB loader >> * Using the same source but switching from the OS cross compiler to the >> one from Yocto/OE >> >> And afterwards I get 100% failure rate with an error as described above. >> >> My suspicion is that there is some memory corruption/conflict. My SPL is >> quite large and I wonder if it exceeds some limit. >> >> SPL is loaded to 0x920000 and CONFIG_SPL_STACK is set to 0x960000, which >> leaves 256 KiB in between for the SPL. But all i.MX8MP boards seem to >> set CONFIG_SPL_MAX_SIZE=0x26000 (152 KiB) for some reason. My >> u-boot-spl-ddr.bin currently has around 193 KiB but I don't get any >> warning about exceeding the SPL_MAX_SIZE. >> >> My questions: >> >> * Why is CONFIG_SPL_MAX_SIZE set to 152 KiB? I guess the remainder between the SPL code and the SPL stack is for the DDR firmware. Which explains why I get failures with SPL exceeding 152 KiB size. Now I also understand the reason why the power init code was implemented using legacy non-DM drivers in other i.MX8MP boards. I probably also need to do this to save some space. >> * Why is there no warning in my case? Still, I fail to see why there isn't any error or where the size check is even implemented. >> * Any other ideas or pointers? >> >> Thanks for your help! >> >> Best regards >> Frieder > > >