Hi Sam,
Your problem with dram_size() may be that it tests memory beyond the maxsize given.
for (cnt = maxsize / sizeof (long); cnt > 0; cnt >>= 1) { addr = base + cnt; /* pointer arith! */
save[i++] = *addr; *addr = ~cnt; }
If maxsize = 16M, initial cnt = 4M, so if base = 0, the first time through the loop, addr = 16M which is the first address outside of the memory range given to test.
The reason it usually works is that most boards make the AM (address mask) in the OR (option register) of the memory controller specify more memory than they actually need.
This may be the easy way to fix it, however I would say the correct way would be to change the lines for (cnt = maxsize / sizeof (long); cnt > 0; cnt >>= 1) { for (cnt = 1; cnt <= maxsize / sizeof (long); cnt <<= 1) { to for (cnt = maxsize / sizeof (long) / 2; cnt > 0; cnt >>= 1) { for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
Unfortunately it appears in many board specific versions.
While I'm at it, the entire function should be moved to a file in the common directory and the function definition changed to long int dram_size (long int *base, long int maxsize)
The setting of the MxMR (memory A/B mode register) has nothing to do with determining the DRAM size and should be done in the calling function which is board specific.
I know, I'm free to submit a patch, but I'm a combination of busy and lazy.
Chris