Why? The Brother provided Linux drivers have parts that are compiled for i386 and have no source code. Although there is an open source Brother Printer driver, it is not optimizied for cheap printers with small cache. It fails part way into a print on large images or busy pages.

So, how do we port the closed-source driver to another architecture? There are several methods:

• Run i386 code on ARM through an emulator. However, if you are using RPi the emulation layer will make it terribly slow.
• Reverse engineer and compile the required parts for ARM. This has only been done for rawtobr3 as far as I know. There is also an original source available for brcupsconfig4, but other part are missing.
• Scavange and collect Brother's own code into full ARM install packages. This is the approach taken here.

Run the oh_brother.zsh script with the model of the printer that you have, like this ./oh_brother.zsh HL-4570CDW

In case this does not work, read below:

Many Brother printers are designed for LPR and lack support for common page description languages (PDF, PCL, etc). They require a CUPS wrapper to translate the options to their native speak.

There are at least four Brother provided pre-compiled x86 32-bit binaries and can not run on ARM/ARM64. Specifically:

• /usr/local/Brother/Printer/HL2270DW/cupswrapper/brcupsconfig4 - wrapper that calls on brprintconflsr3 to set up /usr/share/Brother/inf on every print to pass the current options.
• /usr/local/Brother/Printer/HL2270DW/lpd/rawtobr3 - converter for the job to a raster format. Seems to be model-agnostic. Called by /opt/brother/Printers/BrGenPrintML2/lpd/lpdfilter
• /usr/local/Brother/Printer/HL2270DW/inf/brprintconflsr3 - translates job options to Brother format. Seems to be backward compatible. Called by /opt/brother/Printers/BrGenPrintML2/cupswrapper/lpdwrapper from brgenprintml2pdrv-4.0.0-1.i386.deb which is itself in the opt/brother/Printers/BrGenPrintML2/cupswrapper/brother-BrGenPrintML2-cups-en.ppd
• /usr/local/Brother/Printer/HL2270DW/inf/braddprinter - adds alphanumeric printer model name to /usr/share/Brother/inf/brPrintList upon installation. This can be safely ignored.

Below is the example of how to create ARM packages for HL2270DW, but it should work for other printers, both on ARM64 and ARM32 RPis. Substitute the proper packages for your printer. To find these packages:

• Head out to the Brother website and grab the native i386 Linux deb pacakges. Or
• Use tools/web_brother.sh from a Brother copyist or curl http://www.brother.com/pub/bsc/linux/infs/<uppercasedmodelhere> and then grab these packages from http://www.brother.com/pub/bsc/linux/packages/. Or
• Run the linux-brprinter-installer with set -e injected to see all the URLs that its probing before it confirming the installation.

Oh, yeah and next time just buy a printer that has Driverless printing or IPP Everywhere

Note: if you just want to install the precompiled packages grab them from this repo and run sudo apt install psutils cups; sudo dpkg -i hl2270dwlpr-2.1.0-1.armhf.deb cupswrapperHL2270DW-2.0.4-2.armhf.deb. Steps below show how to re-create them.

We'll be grabbing 2 native arm32 executables and compile one other. All the steps can be done on RPi or on i386, but you'd need to cross-compile brcupsconfig for armhf on the latter.

Get the original i386 LPR driver, unpack the files and the control information

wget https://download.brother.com/welcome/dlf005893/hl2270dwlpr-2.1.0-1.i386.deb
dpkg -x hl2270dwlpr-2.1.0-1.i386.deb hl2270dwlpr-2.1.0-1.armhf.extracted
dpkg-deb -e hl2270dwlpr-2.1.0-1.i386.deb hl2270dwlpr-2.1.0-1.armhf.extracted/DEBIAN
sed -i 's/Architecture: i386/Architecture: armhf/' hl2270dwlpr-2.1.0-1.armhf.extracted/DEBIAN/control
echo true > hl2270dwlpr-2.1.0-1.armhf.extracted/usr/local/Brother/Printer/HL2270DW/inf/braddprinter

Grab the Brother ARM drivers from a generic armhf archive they provide and copy the ARM code into the unpacked folders. Note that HL2270 does not use brprintconflsr3.

wget http://download.brother.com/welcome/dlf103361/brgenprintml2pdrv-4.0.0-1.armhf.deb
dpkg -x brgenprintml2pdrv-4.0.0-1.armhf.deb brgenprintml2pdrv-4.0.0-1.armhf.extracted
# cp brgenprintml2pdrv-4.0.0-1.armhf.extracted/opt/brother/Printers/BrGenPrintML2/lpd/armv7l/brprintconflsr3 hl2270dwlpr-2.1.0-1.armhf.extracted/usr/local/Brother/Printer/HL2270DW/lpd
cp brgenprintml2pdrv-4.0.0-1.armhf.extracted/opt/brother/Printers/BrGenPrintML2/lpd/armv7l/rawtobr3 hl2270dwlpr-2.1.0-1.armhf.extracted/usr/local/Brother/Printer/HL2270DW/lpd

Now repackage it

cd hl2270dwlpr-2.1.0-1.armhf.extracted
find . -type f ! -regex '.*.hg.*' ! -regex '.*?debian-binary.*' ! -regex '.*?DEBIAN.*' -printf '%P ' | xargs md5sum > DEBIAN/md5sums
cd ..
chmod 755 hl2270dwlpr-2.1.0-1.armhf.extracted/DEBIAN/p* hl2270dwlpr-2.1.0-1.armhf.extracted/usr/local/Brother/Printer/HL2270DW/inf/* hl2270dwlpr-2.1.0-1.armhf.extracted/usr/local/Brother/Printer/HL2270DW/lpd/*
dpkg-deb -b hl2270dwlpr-2.1.0-1.armhf.extracted hl2270dwlpr-2.1.0-1.armhf.deb

Grab and extract the brcupsconfig4 sources

wget https://download.brother.com/welcome/dlf006733/brhl2270dwcups_src-2.0.4-2.tar.gz
tar zxvf brhl2270dwcups_src-2.0.4-2.tar.gz
cd brhl2270dwcups_src-2.0.4-2

Compile brcupsconfig4

gcc brcupsconfig3/brcupsconfig.c -o brcupsconfig4

If you are running these steps on the arm64 platform do cross complilation by first getting arm-linux-gnueabihf-gcc-9 via sudo apt install gcc-9-arm-linux-gnueabihf and then running arm-linux-gnueabihf-gcc-9 brcupsconfig3/brcupsconfig.c -o brcupsconfig4

Grab the original i386 CUPS wrapper and unpack it

wget https://download.brother.com/welcome/dlf005895/cupswrapperHL2270DW-2.0.4-2.i386.deb
dpkg -x cupswrapperHL2270DW-2.0.4-2.i386.deb cupswrapperHL2270DW-2.0.4-2.armhf.extracted
dpkg-deb -e cupswrapperHL2270DW-2.0.4-2.i386.deb cupswrapperHL2270DW-2.0.4-2.armhf.extracted/DEBIAN
sed -i 's/Architecture: i386/Architecture: armhf/' cupswrapperHL2270DW-2.0.4-2.armhf.extracted/DEBIAN/control

Copy the compiled code into the unpacked folder

cp brhl2270dwcups_src-2.0.4-2/brcupsconfig4 cupswrapperHL2270DW-2.0.4-2.armhf.extracted/usr/local/Brother/Printer/HL2270DW/cupswrapper

Repack it

cd cupswrapperHL2270DW-2.0.4-2.armhf.extracted
find . -type f ! -regex '.*.hg.*' ! -regex '.*?debian-binary.*' ! -regex '.*?DEBIAN.*' -printf '%P ' | xargs md5sum > DEBIAN/md5sums
cd ..
chmod 755 cupswrapperHL2270DW-2.0.4-2.armhf.extracted/DEBIAN/p* cupswrapperHL2270DW-2.0.4-2.armhf.extracted/usr/local/Brother/Printer/HL2270DW/cupswrapper/*
dpkg-deb -b cupswrapperHL2270DW-2.0.4-2.armhf.extracted cupswrapperHL2270DW-2.0.4-2.armhf.deb

Note: if you are using RPi4 64 bit OS (AARCH64 aka ARM64) you need to install libc6:armhf. No need to do it on ARM32 aka AARCH32 aka armhf aka armv7l

sudo dpkg --add-architecture armhf
sudo apt update
sudo apt install libc6:armhf

Install prereqs and install the drivers

sudo apt install psutils cups
sudo dpkg -i hl2270dwlpr-2.1.0-1.armhf.deb cupswrapperHL2270DW-2.0.4-2.armhf.deb

You may need to install other runtime dependencies such as a2ps, glibc-32bit, ghostscript

In case you're missing the printer defeniton you can extract it from the cupswrapper for from a Windows driver distribution using the official brother method

Top extract extract the filter and the PPD file directly from the cupswrapper run this:

sed -e '0,/cat <<!ENDOFWFILTER! >/d' -e '/^!ENDOFWFILTER!/,$d' './cupswrapperHL2270DW-2.0.4' -e 's|\\||g' > ./brlpdwrapperHL2270DW
sed -e '0,/cat <<ENDOFPPDFILE >/d'   -e '/^ENDOFPPDFILE/,$d'   './cupswrapperHL2270DW-2.0.4'              > ./HL2270DW.ppd

Either use the driver installer, which is just a bash script that downloads the debs, or download the debs manually and install

curl -o - https://download.brother.com/welcome/dlf006893/linux-brprinter-installer-2.2.2-1.gz | gunzip > linux-brprinter-installer-2.2.2-1
echo -e "HL2270-DW\ny\nn" | sudo bash linux-brprinter-installer-2.2.2-1
(HL2270-DW as "model name", then y to continue, "no" for "Will you specify the DeviceURI?" choose "No" for USB connection or "Yes" for network connection.

or manually download debs and configure them.

• https://wiki.archlinux.org/index.php/Packaging_Brother_printer_drivers
• https://blog.serverdensity.com/how-to-create-a-debian-deb-package/
• https://wiki.debian.org/CUPSDriverlessPrinting