eeprom Write Protect (corruption on bootrom...)
Created by: RobertCNelson
=> i2c md 0x50 0x00.1 40
0000: 00 55 33 ee 01 37 00 10 2e 00 42 42 4f 4e 45 41 .U3..7....BBONEA
0010: 49 2d 36 34 2d 42 30 2d ff ff ff ff ff ff ff ff I-64-B0-........
0020: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
0030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
Zhangqun Ming 19 days ago Because the first byte is changed to 0x00.
rcn-ee:headphones: 19 days ago waht should it be?
rcn-ee:headphones: 19 days ago i was lookin at: https://github.com/beagleboard/beaglebone-ai-64/issues/5#issuecomment-913942821
rcn-ee:headphones: 19 days ago ugh, that needs to be an aa..
rcn-ee:headphones: 19 days ago thanks for catching that @Zhangqun Ming!!
rcn-ee:headphones: 19 days ago => i2c dev 0 Setting bus to 0 => i2c mw 0x50 0x00.1 aa => i2c md 0x50 0x00.1 20 0000: aa 55 33 ee 01 37 00 10 2e 00 42 42 4f 4e 45 41 .U3..7....BBONEA 0010: 49 2d 36 34 2d 42 30 2d ff ff ff ff ff ff ff ff I-64-B0-........
Zhangqun Ming 19 days ago When you power it up, it fails to read because it writes 2 bytes address, but EEPROM only supports 1 byte address, so the first byte is changed. (edited) image.png image.png
rcn-ee:headphones: 19 days ago That is crazy! so after one reboot... => i2c md 0x50 0x00.1 20 0000: 00 55 33 ee 01 37 00 10 2e 00 42 42 4f 4e 45 41 .U3..7....BBONEA 0010: 49 2d 36 34 2d 42 30 2d ff ff ff ff ff ff ff ff I-64-B0-........
rcn-ee:headphones: 19 days ago so... do we have to lock the eeprom with a write-protect.. right now it's going to a gpio pin, but should we just use a jumper like the BBB's?
rcn-ee:headphones: 19 days ago @jkridner ^ crazy!
jkridner:headphones: 18 days ago The write-protect GPIO isn't working?
jkridner:headphones: 18 days ago getting corrupt?
rcn-ee:headphones: 18 days ago default state is "Write Allow" so when the rom probes it wrong, it corrupts the first bit..
rcn-ee:headphones: 18 days ago (i can write to the eeprom without changing the wr gpio direction)
rcn-ee:headphones: 18 days ago it's been a while, best way to hexdump to a file?
rcn-ee:headphones: 18 days ago root@BeagleBone:/sys/bus/i2c/drivers/at24/2-0050# hexdump eeprom 0000000 55aa ee33 3701 1000 002e 4242 4e4f 4145 0000010 2d49 3436 422d 2d30 ffff ffff ffff ffff
rcn-ee:headphones: 18 days ago That Seeed can use to program..
rcn-ee:headphones: 18 days ago got it..