On 20.11.19 08:26, Iru Cai wrote:
Actually specify whatever chip will be ok. A common chip in the laptops is MX25L6445E, but using MX25L6405 is also ok. I remember the flashrom modified by libreboot has merged all these chips.
Rule of thumb: If libreboot does something downstream, it's wrong.
Reading is always safe, no matter which entry is selected. But, depen- ding on the programmer and options used and the reliability of the connection, all hell can break loose if the wrong entry is selected. The problem is that these chips often use the same commands for erasing different block sizes.
For instance, internal flashing on an Intel system where certain SPI commands can be forbidden, if flashrom erases too much by accident and matching erase block commands are not allowed, it will fail to recover.
If, for any reason, --noverify-all is used and flashrom erases too much at the edge of a region, it will also have backed up too little of sur- rounding flash contents.
If the connection is unreliable, flashrom might make wrong assumptions if something fails. This is actually always true, but becomes much worse when the expected erase-block size is wrong.