On 06.03.2018 23:20, Matthew Leon wrote:
Hey Nico,
I am talking about the internal programmer for a piix4 chipset. For the read, I have gotten to spi_chip_read that returns flash->mst->spi.read(flash,buf,start,len) and I am trying to figure out where mst gets set, or how flashrom gathers the information to set it. For the write, I have gotten to spi_send_multicommand, after digging through spi_nbyte_program. Could you clue me in with a sample piix4 chipset?
AFAICS (from following the code in chipset_enable.c), PIIX4 doesn't support SPI at all. Only parallel flash chips. And these work much differently.
`flash->mst` gets set in probe_flash(). It's just the programmer you select on the command line. For the `internal` programmer this is hard to follow, though. In chipset_enable(), it's decided what that master `mst` actually can do for a given chipset, mostly based on the PCI id list in `chipset_enables`.
Does flashrom read and write to hardware registers? Thank-you so much!
Yes, it does. In case of internal SPI controllers, it pokes registers of that controller. In case of internal parallel flash chips, it seems to directly access memory mapped registers of the flash chip. For the latter have a look at jedec.c and the functions at the end of `internal.c`.
Hope that helps, Nico