I have a spansion S25FL128P......X chip and can do some tests. The "problem" is that i don't know if its an 0 or an 1. On the chip i see only "FL128PIF" and one line lower i see "00299012 C".
Probing works (id1 0x01, id2 0x2018): Calibrating delay loop... OK. serprog: Programmer name is "serprog-duino" Found Spansion flash chip "S25FL128P......0" (16384 kB, SPI) on serprog. Found Spansion flash chip "S25FL128P......1" (16384 kB, SPI) on serprog. Found Spansion flash chip "S25FL128S......0" (16384 kB, SPI) on serprog. Found Spansion flash chip "S25FL128S......1" (16384 kB, SPI) on serprog. Found Spansion flash chip "S25FL129P......0" (16384 kB, SPI) on serprog. Found Spansion flash chip "S25FL129P......1" (16384 kB, SPI) on serprog. Multiple flash chip definitions match the detected chip(s): "S25FL128P......0", "S25FL128P......1", "S25FL128S......0", "S25FL128S......1", "S25FL129P......0", "S25FL129P......1" Please specify which chip definition to use with the -c <chipname> option.
BTW: Chip was fund on a Dell-Systemboard.