I've got a ls1021atwr here. I'm a bit confused about the booting process in ls1021a, before U-Boot Startup. I guess a boot from NOR differs much more from SD-Boot than i thought - or not. Maybe you can help me to understand the startup...
Please correct me if i'm wrong:
A startup with SD-Boot looks like the following:
2. Pre-Boot-Loader get's the cfg_rcw_src to SD-Boot
3. Pre-Boot-Loader load the RCW with Preamble from SD-Card AND the U-Boot SPL into internal RAM
4. The Code in the internal RAM is executed
5. This Code initialize the external RAM...
6. ...And loads the U-Boot into it.
7. The U-Boot Code in the ext. RAM is executed and all is fine.
And now i stock on NOR-Boot:
2. Pre-Boot-Loader get's the cfg_rcw_src to NOR- Boot
3. Pre-Boot-Loader loads the RCW binary from a fixed (where defined?) Adress in NOR. (Why can the PBL already read a NOR-Flash - is there no need to load a driver or whatelse?)
4. Pre-Boot-Loader loads directly the U-Boot without SPL into the external RAM
5. This Code in the external RAM and all is fine.