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user-doc: update write-protect ranges and size

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S.J.R. van Schaik 2017-08-04 16:07:49 +02:00
parent 6e11e9079d
commit 355c537fa2
1 changed files with 23 additions and 15 deletions
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user-doc/user-doc.tex
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@ -227,7 +227,7 @@ flashrom v0.9.4 : bc6cab1 : Oct 30 2014 07:32:01 UTC on Linux 4.9.4-gentoo (x86
vendor="Macronix" name="MX25L6406E"
./flashrom --programmer=buspirate_spi:dev=/dev/buspirate --get-size
flashrom v0.9.4 : bc6cab1 : Oct 30 2014 07:32:01 UTC on Linux 4.9.4-gentoo (x86_64), built with libpci 3.1.10, GCC 4.8.x-google 20140307 (prerelease), little endian
8388608
16777216
\end{minted}
Further, Google's fork of flashrom allows us to tag regions on the SPI NOR flash chip with a custom name.
@ -254,28 +254,36 @@ Now that the images have been written to their respective regions, we can look a
flashrom v0.9.4 : bc6cab1 : Oct 30 2014 07:32:01 UTC on Linux 4.9.4-gentoo (x86_64), built with libpci 3.1.10, GCC 4.8.x-google 20140307 (prerelease), little endian
Valid write protection ranges:
start: 0x000000, length: 0x000000
start: 0x7e0000, length: 0x020000
start: 0x7c0000, length: 0x040000
start: 0x7a0000, length: 0x080000
start: 0x700000, length: 0x100000
start: 0x600000, length: 0x200000
start: 0x400000, length: 0x400000
start: 0x000000, length: 0x800000
start: 0x000000, length: 0x800000
start: 0xfc0000, length: 0x040000
start: 0xf80000, length: 0x080000
start: 0xf00000, length: 0x100000
start: 0xe00000, length: 0x200000
start: 0xc00000, length: 0x400000
start: 0x800000, length: 0x800000
start: 0x000000, length: 0x040000
start: 0x000000, length: 0x080000
start: 0x000000, length: 0x100000
start: 0x000000, length: 0x200000
start: 0x000000, length: 0x400000
start: 0x000000, length: 0x600000
start: 0x000000, length: 0x700000
start: 0x000000, length: 0x780000
start: 0x000000, length: 0x7c0000
start: 0x000000, length: 0x7e0000
start: 0x000000, length: 0x800000
start: 0x000000, length: 0x1000000
start: 0xfff000, length: 0x001000
start: 0xffe000, length: 0x002000
start: 0xffc000, length: 0x004000
start: 0xff8000, length: 0x008000
start: 0xff8000, length: 0x008000
start: 0x000000, length: 0x001000
start: 0x000000, length: 0x002000
start: 0x000000, length: 0x004000
start: 0x000000, length: 0x008000
start: 0x000000, length: 0x008000
\end{minted}
Since we don't want our images to be tampered with, we want to enable write-protection for the full range.
We can configure the write-protected range as follows:
\begin{minted}[breaklines]{text}
./flashrom --programmer=buspirate_spi:spispeed=2M,dev=/dev/buspirate --wp-range 0x000000 0x800000
./flashrom --programmer=buspirate_spi:spispeed=2M,dev=/dev/buspirate --wp-range 0x000000 0x1000000
\end{minted}
After setting the range, we are still able to modify the contents of the entire SPI NOR flash chip.