1. Read seems to work:
$ flashrom -r ttt.bin flashrom v0.9.2-r1001 on FreeBSD 9.0-CURRENT (i386), built with libpci 3.1.7, GCC 4.2.1 20070719 [FreeBSD] flashrom is free software, get the source code at http://www.flashrom.org
No coreboot table found. Found chipset "Intel ICH4/ICH4-L", enabling flash write... OK. This chipset supports the following protocols: Non-SPI. Calibrating delay loop... OK. Found chip "SST SST49LF003A/B" (384 KB, FWH) at physical address 0xfffa0000. === This flash part has status UNTESTED for operations: ERASE WRITE The test status of this chip may have been updated in the latest development version of flashrom. If you are running the latest development version, please email a report to flashrom@flashrom.org if any of the above operations work correctly for you with this flash part. Please include the flashrom output with the additional -V option for all operations you tested (-V, -Vr, -Vw, -VE), and mention which mainboard or programmer you tested. Thanks for your help! === Reading flash... done.
$ ls -l ttt.bin -rw-r--r-- 1 root citrin 393216 Jun 9 20:48 ttt.bin
full read log with -V: http://citrin.ru/tmp/flashrom_ASUS_P4BP-MX_read.log
2. Write don't work:
=== Flash image seems to be a legacy BIOS. Disabling checks. Writing flash chip... Erasing flash chip... ERASE FAILED at 0x00000000! Expected=0xff, Read=0x24, failed byte count from 0x00000000-0x00000fff: 0xfef ERASE FAILED! ERASE FAILED at 0x00000000! Expected=0xff, Read=0x24, failed byte count from 0x00000000-0x0000ffff: 0xfeec ERASE FAILED! FAILED! ERASE FAILED! FAILED! Your flash chip is in an unknown state. Get help on IRC at irc.freenode.net (channel #flashrom) or mail flashrom@flashrom.org!
full write log: http://citrin.ru/tmp/flashrom_ASUS_P4BP-MX_write.log
3. after failed write flash seems to be not corrupted: md5 for file from flashrom -r is same as before.