Hi tns1,
> I am also thinking of putting u-boot in the EPCS.
I'm doing this now on one of my boards ... it works very
nicely -- kudos to Altera :-)
> Is there any documentation that talks about the EPCS
> bootloader and how it works?
See Chapter 12 of the "Nios II Processor Reference Handbook", and
1-6 of the "Nios II Flash Programmer User Guide" for a description:
http://www.altera.com/literature/hb/nios2/...pu_nii51012.pdf (
http://www.altera.com/literature/hb/nios2/n2cpu_nii51012.pdf)
http://www.altera.com/literature/ug/ug_nio..._programmer.pdf (
http://www.altera.com/literature/ug/ug_nios2_flash_programmer.pdf)
> I am unclear on how it fits in/replaces the standard booting scheme
> and what the active players are. Do I need to have an ASMI or EPCS
> module in my project to make this work?
Yes you need the EPCS component and you need to set your reset
address in the EPCS component memory. The bootloader code in
the EPCS component will then do its thing on reset. The actual code
is in:
{INSTALL_DIR}\kits\nios2\components\altera_nios2\sdk\src\boot_loader_sources
- boot_loader.S (generic code for CFI or EPCS)
- boot_loader_epcs_bits.S (epcs-specific code)
The thing I like most about the EPCS bootloader : I can eliminate parallel
flash altogether for some apps (or just de-pop) ... an epcs and some
PSRAM & I'm done :-)
Regards,
--Scott