I have Spartan-2e board here which resembles to certain extent
Spartan-3e starter kit. There are differences however - SDRAM instead of
DDR, older Microblaze core, higher CPU clock, EMAC instead Etherlite,
etc... I've attached auto-config.h files, generated by Petalogix BSP for
both cases.
I managed to compile and run u-boot and uClinux for both boards.
However there is visible delay - 3-5 sec - when start any application
(like "ls" for instance) on my Spartan-2e target under uClinux. The
following observations have been done:
1) Delay depends on application's size: "ls" which in fact starts
busybox
(200K) takes several seconds to start while small "cat" launches
quickly.
2) On Spartan-3e Starter Kit delay is also visible, but less than on my
Spartan-2e based HW. Note that the Starter Kit CPU clock is little bit
slower than mine (50MHz vs. 64MHz).
3) Simple memory read/write tests (I ran them from BRAM based code) show
that my board performs even better than starter kit which is to be
expected provided that clock is higher.
I sounds for me that uClinux kernel uses some resources (cashes?) which
are not well supported in older Spartan-2e architecture. Can somebody
give me an idea where to look?