fix(usbdevice): use printf with octal escapes for HID report descriptor#7
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frankurcrazy wants to merge 1 commit intoLubanCat:ubuntu20.04from
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fix(usbdevice): use printf with octal escapes for HID report descriptor#7frankurcrazy wants to merge 1 commit intoLubanCat:ubuntu20.04from
frankurcrazy wants to merge 1 commit intoLubanCat:ubuntu20.04from
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The hid_prepare() function uses echo -ne to write the HID report descriptor binary data. On systems where /bin/sh is dash (not bash), echo does not support -ne flags, causing the descriptor to be written as literal ASCII text (e.g., "-ne \x05\x01\x09\x06...") instead of binary bytes. This breaks HID keyboard emulation entirely — the USB host cannot parse the descriptor, sends infinite bus resets, and writes to /dev/hidg0 block indefinitely. Replace echo -ne with printf using octal escapes, which work correctly across all POSIX shells (bash, dash, sh). Fixes: LubanCat#6
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Summary
hid_prepare()inusbdeviceto write binary HID report descriptor correctly under dashProblem
echo -ne "\x05\x01..."does not work in dash (the default/bin/sh). It writes literal text-ne \x05\x01...instead of binary bytes, breaking HID keyboard emulation entirely.Fix
Replace
echo -newithprintfusing octal escapes, which work correctly across all POSIX shells.Testing
Verified on RK3588 (LubanCat) with:
All devices successfully enumerate and receive HID keystrokes with the fix.
Fixes #6
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