Tested with "flashrom v0.9.7-r1796". Chip is still "UNTESTED" for all operations, but probe, read, erase and write works. Tested many times with random data. Always ok.
I also tested the erase functions: Function 0 -> ok Function 1 -> ok Function 3 -> Not OK!
The output is: Found Atmel flash chip "AT45DB021D" (264 kB, SPI). This chip may contain one-time programmable memory. flashrom cannot read and may never be able to write it, hence it may not be able to completely clone the contents of this chip (see man page for details). === This flash part has status UNTESTED for operations: PROBE READ 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, -VE, -Vw), and mention which mainboard or programmer you tested. Please mention your board in the subject line. Thanks for your help! Erasing and writing flash chip... Trying erase function 0... 0x000000-0x00083f:E, 0x000840-0x0083ff:E, 0x008400-0x0107ff:EError: invalid response 0x11 from device at45db_erase: error sending erase command! Reading current flash chip contents... Error: invalid response 0xE9 from device spi_read_at45db: error sending read command! Can't read anymore! Aborting. FAILED! Your flash chip is in an unknown state. Please report this on IRC at chat.freenode.net (channel #flashrom) or mail flashrom@flashrom.org, thanks!
But writing with this mode works! Output: Found Atmel flash chip "AT45DB021D" (264 kB, SPI). This chip may contain one-time programmable memory. flashrom cannot read and may never be able to write it, hence it may not be able to completely clone the contents of this chip (see man page for details). === This flash part has status UNTESTED for operations: PROBE READ 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, -VE, -Vw), and mention which mainboard or programmer you tested. Please mention your board in the subject line. Thanks for your help! Reading old flash chip contents... done. Erasing and writing flash chip... Trying erase function 0... 0x000000-0x00083f:W, 0x000840-0x0083ff:W, 0x008400-0x0107ff:S, 0x010800-0x018bff:S, 0x018c00-0x020fff:S, 0x021000-0x0293ff:S, 0x029400-0x0317ff:S, 0x031800-0x039bff:S, 0x039c00-0x041fff:S Erase/write done. Verifying flash... VERIFIED.
Hope it helps!
Greetings