diskos/corresponding-source/README.md

Corresponding source for the shipped GPL/LGPL native binaries

The installer ships prebuilt native tools under vendor/<os>-<arch>/. Some of them are, or statically link, GPL-2.0 / LGPL-2.1 code. To satisfy those licenses this directory carries the complete corresponding source for the exact upstream versions those binaries were built from - so the source travels from the same place as the binaries (GPL-2.0 §3(a) + the "same place" clause in §3's final paragraph; LGPL-2.1 §6(a)/(d)).

Each item below is a full Debian source package (.orig upstream tarball + .debian packaging + .dsc); extract with dpkg-source -x <name>.dsc (or unpack the .orig tarball directly).

Shipped binary	Component here	Version	License	Source files
mksquashfs / unsquashfs	squashfs-tools	4.6.1-1build1	GPL-2.0	squashfs-tools_4.6.1*
(statically linked into the above)	liblzo2 (lzo2)	2.10-2build4	GPL-2.0-or-later	lzo2_2.10*
usbboot	libusb-1.0 (statically linked)	1.0.27-1	LGPL-2.1	libusb-1.0_1.0.27*
all three tools (static C runtime)	glibc	2.39-0ubuntu8.8	LGPL-2.1-or-later	glibc_2.39*
usbboot	its own C source	-	GPL-2.0-or-later	../src/usbboot/usbboot.c
disc_spl_lpddr3.bin	stage-1 SPL (u-boot-xburst)	see ../SPL_SOURCE.md	GPL-2.0	../spl-src/

Also statically linked into mksquashfs/unsquashfs: zlib and liblzma/xz - both permissive (zlib / 0BSD-public-domain), needing attribution only (see ../NOTICE.md), not corresponding source.

Rebuilding the binaries from this source

The build scripts that produced the shipped binaries are in ../build/:

• build/build-squashfs-static.sh - static mksquashfs/unsquashfs (gzip+lzo+xz), with an LZO round-trip self-test. Uses squashfs-tools + liblzo2 above.
• build/build-usbboot-static.sh - fully static usbboot, rebuilding libusb (above) with --disable-udev --enable-static so no libudev/libcap is pulled in.

Those scripts fetch the same upstream source via apt-get source; the tarballs here pin the exact versions used so you can rebuild - or substitute your own modified libusb and relink usbboot (the LGPL-2.1 §6 relink path) - without depending on a distribution's source availability.

The LGPL-2.1 relink path for libusb (usbboot)

usbboot statically links libusb-1.0.a. To exercise your LGPL right to run usbboot against a modified libusb: extract libusb-1.0_1.0.27*, modify it, ./configure --disable-udev --enable-static --disable-shared && make, then relink with the app source and the same command build/build-usbboot-static.sh uses (gcc -O2 -std=c99 -I<libusb-inc> -static -o usbboot ../src/usbboot/usbboot.c <your libusb-1.0.a> -lpthread).