[flashrom] Re: Truncating flash for oversized image
Thanks for the response guys! I went ahead and cut down the ROM last week after sending this out, and was able to successfully flash my part. I very much understand why you would have the interlock in there for ROM sizing, especially since this can run an in system BIOS flash. Having people blindly download ROMs off the internet and brick their systems without external flashers or JTAG doesn't sound like the most fun to support. That said, I'm glad to see support in this tool for various voltages and speeds. I often do some pretty hacky reworks to get things programmed, so this is useful stuff to have available in the command line tool! --Rob On Mon, Nov 1, 2021 at 4:15 AM Angel Pons wrote: > Hi Rob, > > On Sun, Oct 31, 2021 at 10:18 PM David Hendricks > wrote: > > > > On Sun, Oct 31, 2021 at 10:10 AM Rob Shore wrote: > >> > >> Hello! > >> > >> I've just discovered Flashrom as a way to use a Dediprog SPI programmer > with MacOS, which is awesome. I've got a bit of a strange question though: > >> > >> I've got a 1Mbit rom on a board, but the image I was given for it is > for a 2Mbit part. The firmware itself in the raw image is < 1Mbit, but the > file is still larger than my ROM. Flashrom won't run the flash saying > "Error: Image size (262144 B) doesn't match the flash chip's size (131072 > B)!", which is technically correct. Is there a way to force the flash, and > just have the process end after the first 131072B, which would result in > the data I need being on the ROM? > >> > >> Thanks, and looking forward to using this tool some more! > > > > Try one of these: > > - Use a layout file to tell flashrom exactly where you intend to write: > `echo "0:01 fw" > layout.txt && flashrom -p dediprog -l layout.txt > -i fw --noverify-all -w ` > > - Create a new file that is the appropriate size, for example using `dd > if= of= bs=1k count=128` > > I think the first approach won't work, as flashrom still wants the > file size to be exactly that of the flash chip. In these cases, one > needs to manually adjust the file. If the file is too small, add some > padding before and/or after its contents. If the file is too large, > extract a subsection of the desired size (see David's second > approach). Because this depends on the firmware contents and use case, > flashrom cannot do this automatically. > > > The size check is an intentional UI decision to help prevent writing an > incorrect file to the flash. A little bit of extra caution here is > typically much easier than recovering a bricked host. > > Indeed. Having to perform some extra steps before flashing is much > better than having to recover a bricked system. > > > ___ > > flashrom mailing list -- flashrom@flashrom.org > > To unsubscribe send an email to flashrom-le...@flashrom.org > > Best regards, > Angel > ___ flashrom mailing list -- flashrom@flashrom.org To unsubscribe send an email to flashrom-le...@flashrom.org
[flashrom] Re: Truncating flash for oversized image
Hi Rob, On Sun, Oct 31, 2021 at 10:18 PM David Hendricks wrote: > > On Sun, Oct 31, 2021 at 10:10 AM Rob Shore wrote: >> >> Hello! >> >> I've just discovered Flashrom as a way to use a Dediprog SPI programmer with >> MacOS, which is awesome. I've got a bit of a strange question though: >> >> I've got a 1Mbit rom on a board, but the image I was given for it is for a >> 2Mbit part. The firmware itself in the raw image is < 1Mbit, but the file is >> still larger than my ROM. Flashrom won't run the flash saying "Error: Image >> size (262144 B) doesn't match the flash chip's size (131072 B)!", which is >> technically correct. Is there a way to force the flash, and just have the >> process end after the first 131072B, which would result in the data I need >> being on the ROM? >> >> Thanks, and looking forward to using this tool some more! > > Try one of these: > - Use a layout file to tell flashrom exactly where you intend to write: `echo > "0:01 fw" > layout.txt && flashrom -p dediprog -l layout.txt -i fw > --noverify-all -w ` > - Create a new file that is the appropriate size, for example using `dd > if= of= bs=1k count=128` I think the first approach won't work, as flashrom still wants the file size to be exactly that of the flash chip. In these cases, one needs to manually adjust the file. If the file is too small, add some padding before and/or after its contents. If the file is too large, extract a subsection of the desired size (see David's second approach). Because this depends on the firmware contents and use case, flashrom cannot do this automatically. > The size check is an intentional UI decision to help prevent writing an > incorrect file to the flash. A little bit of extra caution here is typically > much easier than recovering a bricked host. Indeed. Having to perform some extra steps before flashing is much better than having to recover a bricked system. > ___ > flashrom mailing list -- flashrom@flashrom.org > To unsubscribe send an email to flashrom-le...@flashrom.org Best regards, Angel ___ flashrom mailing list -- flashrom@flashrom.org To unsubscribe send an email to flashrom-le...@flashrom.org
[flashrom] Re: Truncating flash for oversized image
On Sun, Oct 31, 2021 at 10:10 AM Rob Shore wrote: > Hello! > > I've just discovered Flashrom as a way to use a Dediprog SPI programmer > with MacOS, which is awesome. I've got a bit of a strange question though: > > I've got a 1Mbit rom on a board, but the image I was given for it is for a > 2Mbit part. The firmware itself in the raw image is < 1Mbit, but the file > is still larger than my ROM. Flashrom won't run the flash saying "Error: > Image size (262144 B) doesn't match the flash chip's size (131072 B)!", > which is technically correct. Is there a way to force the flash, and just > have the process end after the first 131072B, which would result in the > data I need being on the ROM? > > Thanks, and looking forward to using this tool some more! > Try one of these: - Use a layout file to tell flashrom exactly where you intend to write: `echo "0:01 fw" > layout.txt && flashrom -p dediprog -l layout.txt -i fw --noverify-all -w ` - Create a new file that is the appropriate size, for example using `dd if= of= bs=1k count=128` The size check is an intentional UI decision to help prevent writing an incorrect file to the flash. A little bit of extra caution here is typically much easier than recovering a bricked host. ___ flashrom mailing list -- flashrom@flashrom.org To unsubscribe send an email to flashrom-le...@flashrom.org
