HP printers firmware uploader

This is not quite true. These dependencies are only needed if you are intending to rasterize your content directly using ReadyNAS (which is probably not a good idea anyway). You don't want to run GhostScript on ReadyNAS, it is slow enough on a proper PC. If you are planning to use ReadyNAS to send raw raster data to the printer (and rasterize from a full-sized PC with a Windows or Linux driver that is readily available), you only need to ensure that the appropriate firmware is loaded into the printer at the beginning.

The actual uploading of firmware, assuming it is in correct binary form, takes just one line of script:

cat /usr/share/foo2zjs/firmware/sihp1020.dl > /dev/usb/lp0

(see "INSTALL" in foo2zjs). The rest of the work in bin\sh script "hplj1000" supplied as part of foo2zjs distribution is devoted to ensuring that correct firmware gets uploaded to correct printers and that only the relevant printers are affected. Hence, the lion share of work has already been done, one only needs to ensure that this script does not try to do anything ReadyNAS's shell cannot do and ensure that the paths structure is correct.

Once this is done, one needs to install this script as a "hotplug driver", which is done by the following section of the "makefile" (I omitted some unnecessary details):

USBDIR=/etc/hotplug/usb
UDEVDIR=/etc/udev/rules.d
RULES=hplj10xx.rules
install-hotplug-prog:
	if [ -d $(UDEVDIR) ]; then \
	    $(INSTALL) -c -m 644 $(RULES) $(UDEVDIR)/11-$(RULES); \
	fi
	[ -d $(USBDIR) ] || $(INSTALL) -d -m 755 $(USBDIR)/
	$(INSTALL) -c -m 755 hplj1000 $(USBDIR)/
	ln -sf $(USBDIR)/hplj1000 $(USBDIR)/hplj1005
	ln -sf $(USBDIR)/hplj1000 $(USBDIR)/hplj1018
	ln -sf $(USBDIR)/hplj1000 $(USBDIR)/hplj1020
	$(USBDIR)/hplj1000 install-usermap
	$(USBDIR)/hplj1005 install-usermap
	$(USBDIR)/hplj1018 install-usermap
	$(USBDIR)/hplj1020 install-usermap
	# modprobe usblp
	$(USBDIR)/hplj1000 install-usblp

I do not understand the ways of linux, hence I find it difficult to comprehend exactly what is going on here. Apparently, some command lines involving the bin\sh script are somehow registered. File with "RULES" seems to contain various conditions for recognizing the printers. Whenever one calls hplj1000 with the "magic" parameter "install-usermap", one actually registers the driver in /etc/hotplug/usb.usermap

The only step which may involve compilation is conversion of firmware images into correct binary format. However, this only needs to be done once, can be done on a on a full-sized PC and, frankly, sounds like the least of our concerns. The rest is basically adaptation of an existing script to the somewhat special install of Linux.