Programming LPC/FWH flash SST49LF016C using Raspberry PI

My friend screwed up Panasonic CF-U1 BIOS. The BIOS was locked with password and after a BIOS reflash, the computer was asking for password on startup too. We obtain an original BIOS image from manufacturer, but there was no way to program it.

Hardware part

We took the chip out of computer, glued the chip with tape to thick white paper and marked the pin signals and numbers on borders of paper. Then we solder thin wires (from stranded wire) to pins we need to program the chip and using the tape, we secure them to the labels. It is better to use the tape after soldering every wire, because is difficult to make the soldering good and the joints will tear off after few bends.

SST49LF016C on breakout board

Now we need to connect the chip to Raspberry PI. We use old 40-pin ATA cable for this. It perfectly fits the Raspi GPIO connector. We cut one connector, leaving only one connector and about 30 cm long cable. Separated the wires for example with multiple of 5 (for better counting). Solder the wires to the "breakout board". After soldering each pin we use the tape to secure it on paper.
We use following table of connections:

Mnemonic	Chip Pin No	Raspi GPIO Header Pin	Raspi GPIO Logical No
VSS	24	9	GND
ID0-ID3	17,18,19,20	9	GND
GPI0-GPI4	14,13,12,11,6	9	GND
VDD	30	17	+3.3V
INIT#	32	17	+3.3V
RST#	10	11	GPIO 17
LAD0	21	15	GPIO 22
LAD1	22	16	GPIO 23
LAD2	23	18	GPIO 24
LAD3	25	22	GPIO 25
LFRAME	31	13	GPIO 27
LCLK	7	12	GPIO 18
WP# + TBL#	15,16	7	GPIO 4

Don't forget to put 0.1uF capacitor close to the chip VSS and VDD pins (it is really necessary).

Flat cable connected to breakout board and Raspi

Close up of flat cable connections

Software part

Software for erasing, programming, reading and verifying is written in C. It is compiled using gcc directly on Raspberry PI. Software is using wiringPI library for working with GPIO. Follow direction on wiringPI page for installing.

Project files are stored on my Google Drive: Browse Project Files

Compiling is done in shell with command:

$ gcc flasher.c -l wiringPi -o flasher

Output is binary file with name flasher. We can run it with command and it prints parameters:

$ ./flasher
SST49LF016C flash programmer
Usage: ./flasher parameters
Parameters:
 -w                Write to flash (flash is not erased)
 -e                Erase flash sectors before writing (sector size is 4KB, erases all sectors in writing range)
 -r                Read the flash
 -v                Verify the flash
 -f filename      Specifies file for writng, reading, verifying
 -s hex (32-bit)  Sets start address (hex)
 -o hex (32-bit)  Offset in file - Seeks in input file before operation
 -l hex (32-bit)  Length (how much bytes will be written, read)
 -b hex (8-bit)   Block size (allowed sizes are RW:0x1,0x2,0x4; R:0x10,0x80
 -cW hex (8-bit)   Chip Command for writing (default 0x40)
 -cR hex (8-bit)   Chip Command for reading (default 0xff)

Reading memory:

$ sudo ./flasher -r
Starting address 0x400000
Length 0x4
Block size 0x4
Command for Writing 0x10
Command for Reading 0xff
Preparing pins
Reading
00400000: 4d 45 49 5f MEI_

Writing memory:

$ sudo ./flasher -e -w -v -f R12-0022.U12 -b 0x4 -s 0x400000 -l 0x200000

File specified with -f is binary image. Filename R12-0022.U12 was original filename of BIOS image (in our case).