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libdmview_open: read the view whole, close it, then make the view - #20
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The .dmv stayed open while the view was made of it - which loads its fonts and images, seconds at a board's start. FatFs locks a file open for reading against writing: sending a new view to the card (dmod-boot's install-all, right after the board started) was cancelled at carhmi.dmv, being shown just then. The file is read into memory and closed first. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This was referenced Oct 12, 2026
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Summary
libdmview_open()kept the.dmvopen for the whole time the view was being made of it. That includes loading its fonts and images, which takes seconds at a board's start.FatFs (
FF_FS_LOCK) does not let a file that is open for reading be opened for writing. So sending a new view to the card right after the board started (dmod-boot'sinstall-all) was cancelled atcarhmi.dmv, which dmview was opening just then:Now the file is read whole into memory and closed, and the view is made from that buffer; the buffer is freed afterwards. The file is locked only while it is read (≈85 KB for carhmi's view). Fonts and images were already opened, read and closed one by one.
Test plan
ctest: all passymodem_send.py --wait 90 build/sdcardstraight away (whatinstall-alldoes). Without the fix this is cancelled atcarhmi.dmv: header, reproduced. With it, all 46 files go through, twice in a row.🤖 Generated with Claude Code