[coreboot] SST25VF016B (2MB) flash on m57sli (IT8716F).
c-d.hailfinger.devel.2006 at gmx.net
Thu Jan 17 01:24:38 CET 2008
On 17.01.2008 00:13, Ronald Hoogenboom wrote:
> I mounted a SST25VF016B 2MByte flash chip on the second SPI bios
> landpattern on the m57sli mobo (as per the m57sli tutorial).
> There as some problems with that[...]
> Problem1 (for reading) is solved by NOT using the mmap method for
> reading the flash contents, but using outb() for sending the flash read
> commands (using a specific 25vf016 read function). Also the normal read
> command is only supported up to 25MHz by this chip, so I cannot use the
> 33MHz speed as used normally by spi.c. There is also a 'high speed' read
> command (0x0b), which inserts an extra dummy byte between address and
> data, but as the 8716 only allows max. 3 bytes read per io transfer, the
> gain (3 bytes per io transfer @ 16MHz versus 2 bytes per io transfer @
> 33MHz) is negligible.
Please be aware that the M57SLI may read the reset vector and other
really early stuff at 33 MHz, thereby causing read errors (sometimes
single bit shifts) which are really hard to find.
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