This is a continuation of the discussion at e2e.ti.com/.../am6548-sbl-doesn-t-load-appimage-from-pdk-example
Hello Nick,
I am also not familar with the PCIe, and a search in the device tree files found no MSMC reference, probably PCIe drivers use unused MSMC implicitly.
Good point, I found that after declaring the R5F region in the MSMC, PRUETHs are then unable to work. Specifically, command "ip a" didn't show the interfaces, and there are following boot warning message:
[ 14.255681] icssg-prueth icssg1-eth: unable to allocate MSMC resource [ 14.285992] icssg-prueth: probe of icssg1-eth failed with error -12 [ 14.298694] icssg-prueth icssg0-eth: unable to allocate MSMC resource [ 14.305355] icssg-prueth: probe of icssg0-eth failed with error -12 [ 14.318805] icssg-prueth icssg2-eth: unable to allocate MSMC resource [ 14.323805] icssg-prueth: probe of icssg2-eth failed with error -12
Per the provided spec, we then got only ~512KB or less memory for running R5F app in the SRAM. Seems we need either resort to DDR for running R5F apps that have large file size or adjust PRUETH to use the DDR.
Just out of curious, do you think that running PRUETH firmware in DDR incurs regression on, e.g., latency or throughput?
Thanks!
Huichun