Burngate wrote:Oh - and what are the differences between the various makes of memory, that have to be allowed for - and how many other makes of memory are there, that could be incompatible?
We need to use the data sheet for a specific sdram device and detect that device (from a manufacturer and device code) to detect size, and configure rows, columns and various timings.
Behind the scenes there are continuous negotiations going on for all the components that make the Pi. If a new sdram vendor comes in and offers to undercut the existing vendors,
or if lead times are too high, or volumes available are insufficient then using a new sdram device will be considered.
When a new sdram part is used, we need to update bootcode.bin and start.elf, as older firmware won't work on it.
We were under the belief that NOOBs and the other distributions supported the Micron sdram, but it seems a mistake was made on raspbian, which needs an update.