[coreboot] GA-M57SLI-S4 rev 2.0 dual flash chip modification recipe

[Peter Stuge]

The board can be modified in two ways. One is simpler and less
reliable, the other is more complex but much more robust.

Materials needed:
1x SO-8 SPI flash chip, ideally 200mil but 150mil can work too
   Spansion S25FL016A is easy to get. Macronix has the 32Mbit MX25L3205.
2x 0402 100k chip resistors
1x SPTD (Single Pole Dual Throw) switch and three wires

For the better modification, you also need:
2x 0402 4k7 chip resistors (1k is OK too, 10k does not work!)
2x 0603 100k chip resistors
2x SOT-23 BC847C transistors


See http://stuge.se/m57sli/m57sli_soic_detail_labels.jpg for reference.

Common steps always needed:
1. U9: Populate flash chip
2. R509: Remove
3. R89,R130: Populate 0402 100k resistors

Simple:
NOTE: Keep wires to the switch short! Only a few centimeters/one inch.
4. Solder center contact on switch to Q4-3 or Q5-3. Either is OK.
5. Solder one side contact on switch to Q4-1.
6. Solder other side contact on switch to Q5-1.
7. DONE!

Better:
NOTE: Switch wires can be rather long. Several meters has been tested.
4. R90,R91: Populate 0402 4k7 resistors
5. R86,R389: Populate 0603 100k resistors
6. Q4,Q5: Populate SOT-23 BC847C transistors
7. Solder center contact on switch to VCC, e.g. at BC54-2.
8. Solder one side contact on switch to R86-2.
9. Solder other side contact on switch to R389-2.
10. DONE!


I am happy to sell boards pre-modified with the better modification.
Unfortunately I cannot offer these boards to consumers in all EU
member states because of EU environmental regulations, but many are
OK.

//Peter