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user-doc: add spispeed=2M

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S.J.R. van Schaik 2017-08-03 16:46:33 +02:00
parent a8abfd7432
commit 006e4a70ff
1 changed files with 3 additions and 3 deletions
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user-doc/user-doc.tex
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@ -180,7 +180,7 @@ To speed up the process of writing these images, we have to disable parsing the
Furthermore, to maintain an optimal stability, an SPI speed of no more than 2 MHz is recommended when using the BusPirate v3.6a: Furthermore, to maintain an optimal stability, an SPI speed of no more than 2 MHz is recommended when using the BusPirate v3.6a:
\begin{minted}{text} \begin{minted}{text}
./flashrom --programmer=buspirate_spi:dev=/dev/buspirate -l layout.txt -i uboot:u-boot.bin linux:bzImage initramfs:initramfs.cpio.gz -w --ignore-fmap --fast-verify ./flashrom --programmer=buspirate_spi:spispeed=2M,dev=/dev/buspirate -l layout.txt -i uboot:u-boot.bin linux:bzImage initramfs:initramfs.cpio.gz -w --ignore-fmap --fast-verify
\end{minted} \end{minted}
Now that the images have been written to their respective regions, we can look at the write-protect ranges supported by the chip: Now that the images have been written to their respective regions, we can look at the write-protect ranges supported by the chip:
@ -211,14 +211,14 @@ Since we don't want our images to be tampered with, we want to enable write-prot
We can configure the write-protected range as follows: We can configure the write-protected range as follows:
\begin{minted}{text} \begin{minted}{text}
./flashrom --programmer=buspirate_spi:dev=/dev/buspirate --wp-range 0x000000 0x800000 ./flashrom --programmer=buspirate_spi:spispeed=2M,dev=/dev/buspirate --wp-range 0x000000 0x800000
\end{minted} \end{minted}
After setting the range, we are still able to modify the contents of the entire SPI NOR flash chip. After setting the range, we are still able to modify the contents of the entire SPI NOR flash chip.
To protect the range, we have to enable write protection as follows: To protect the range, we have to enable write protection as follows:
\begin{minted}{text} \begin{minted}{text}
./flashrom --programmer=buspirate_spi:dev=/dev/buspirate --wp-enable ./flashrom --programmer=buspirate_spi:spispeed=2M,dev=/dev/buspirate --wp-enable
\end{minted} \end{minted}
Upon enabling write-protection, the \emph{Write-Protect} (WP) pin has to be pulled low for the write-protection to be effective. Upon enabling write-protection, the \emph{Write-Protect} (WP) pin has to be pulled low for the write-protection to be effective.