1# Flashing firmware standalone 2 3If none of the other methods work, there are three possibilities: 4 5## Desolder 6You must remove or desolder the flash IC before you can flash it. 7It's recommended to solder a socket in place of the flash IC. 8 9When flashing the IC, always connect all input pins. 10If in doubt, pull /WP, /HOLD, /RESET and alike up towards Vcc. 11 12## SPI flash emulator 13If you are a developer, you might want to use an [EM100Pro] instead, which sets 14the onboard flash on hold, and allows to run custom firmware. 15It provides a very fast development cycle without actually writing to flash. 16 17## SPI flash overwrite 18It is possible to set the onboard flash on hold and use another flash chip. 19Connect all lines one-to-one, except /HOLD. Pull /HOLD of the soldered flash IC 20low, and /HOLD of your replacement flash IC high. 21 22### SPI header 23Some boards feature a pin header which is connected to the SPI bus. This can 24also be used to connect a secondary flash chip. 25 26#### HP boards 27Many HP desktop mainboards have a 2x8 or 2x10 block of header pins which 28can be used to connect a second flash chip. One pin is connected to the 29onboard flash's /CS pin, and another is connected to the chipset's /CS 30pin. Normally a jumper cap is placed between these pins, allowing the 31chipset to access the onboard flash. To use this header, remove this 32jumper and connect all lines except /CS one-to-one with the 33corresponding pin on the header. The secondary flash chip's /CS line 34should be connected to the chipset /CS pin on the header. By doing this 35the secondary SPI flash, rather than the onboard flash, will respond to 36accesses from the chipset. 37 38![][hp_spi_header_pinout] 39 40![][hp_spi_header_mainboard] 41 42Note that on boards where this header is unpopulated, a jumper resistor 43will be populated nearby which serves the purpose of the jumper cap. One 44end should have continuity with the /CS pin on the flash, and the other 45end should have continuity with the chipset /CS pin on the unpopulated 46header. It may also be possible to find this resistor through visual 47inspection of the traces on the /CS pins. This resistor should be 48desoldered if you wish to solder a pin header to the board and connect a 49secondary flash, otherwise the onboard flash will always respond to 50accesses. 51 52#### Other boards 53Other boards may have similar headers, but will likely use a different 54pinout than the ones explicitly mentioned here. Usually such a header 55will be located near the onboard SPI flash. If schematics are available, 56the pinout for the header will likely be found in it, but it could also 57be determined using a multimeter in continuity mode to map out the 58connections between the SPI flash and the header. 59 60 61[EM100Pro]: https://www.dediprog.com/product/EM100Pro 62[hp_spi_header_pinout]: hp_spi_header.svg 63[hp_spi_header_mainboard]: hp_spi_header_mb.jpg 64
