Joseph Smith wrote: > Corey, > I am a little confused about the significance of the row_offset in the > i82810 raminit.c. > > 1. What do you mean by row? Each row of DRAM technologies (Side) or > each row of DIMM (Socket)?? Two different things. > > /* Set the row offset, in KBytes (should this be > * Kbits?). Note that this offset is the start of the > * next row. > */ > row_offset = (dimm_size * 4 * 1024);
I'm not entirely sure. I think I asked on the mailing list at one point, but never really got a definite answer. I honestly never got around to testing dual sided function at all, I couldn't find any known-good sticks around here, just one very flaky one. > 2. If this the start of the next row should it be row_offset +1 > Kilobyte?? Perhaps I'm a bit too tired, but I don't think so. IIRC, if you have 64mb of ram, ie 65536k, the last address is at 65535 because addressing starts at 0. The next address, at 65536, would be address 0 of the next row. But I could easily be wrong. And I think that if you screw up the addressing, you also screw up the mode register set, so gotta get it right ;) > > 3. Lastly, is row_offset from function spd_set_dram_size supposed show > up in sdram_enable?? Wouldn?t we need a: > > return row_offset; > > At the end of spd_set_dram_size?? I don't think so, but again I could be wrong. row_offset is declared in sdram_enable then passed along to spd_set_dram_size, which should then be able to modify it. This is one of those "lack of coding experience" situations, where I simply don't know. I really should have checked it, but the cn700 docs were dumped in my lap and it was time to get back to that. I suppose the easiest way to check if this is working correctly or not would be to set row_offset to some arbitrary number at the end of spd_set_dram_size, then dump it to the console after exiting, ie in sdram_enable. > For me it just shows as 0? > > > Thanks - Joe > Not exactly sure what you mean. Are you dumping it inside spd_set_dram_size or after? -Corey -- linuxbios mailing list [email protected] http://www.linuxbios.org/mailman/listinfo/linuxbios
