Linux Format - UK (2020-03)

(Antfer) #1
34 LXF260 March 2020 http://www.linuxformat.com

Raspberry Pi projects


ew hardware is very exciting, and the natural
response to a spiced-up Pi would be to abuse it
to the max. So why not use it as a full PC? Yes,
it has always been technically possible to use a Pi as a
functioning desktop PC. Even the Raspberry Pi 1 Model
B, with its 512MB RAM and 700MHz ARMv6 CPU could
manage a rudimentary desktop, in much the same way
as you can force a Commodore 64 to run a GUI or even
a Linux analog if you’re crazy. Of course, those with long
memories will remember PCs of yesteryear running with
far lighter specs, but they weren’t the size of a credit
card, with a severely limited architecture.
While there’s been incremental improvement in the
Pi’s desktop performance over the years, the new
hardware in the Pi 4 does away with the “technically
possible” part of the equation: it is not just feasible to
run a Pi 4 as a desktop machine, it is positively

pleasurable, so much so that the Raspberry Pi
Foundation is selling its own Raspberry Pi desktop kit.
That new processor has enough muscle to fling around
whatever you might throw at it. Network and USB no
longer share the same bus, there are multiple monitor
outputs on board, and (depending on the spec you pick)
your desktop OS can access up to 4GB RAM. Usually.
There are some caveats for the over-excited, before
we get too involved. This will never replace your high-
end desktop machine. That would be preposterous – it’s
a $55 bundle of electronics, not a $1,000 killer rig.
Realistically, unearthing old desktop hardware and
slapping some variety of Linux on it will offer a much
more capable and flexible experience. This isn’t only
because that hardware is typically much faster, with
functions that are given to dedicated hardware on
traditional PCs forced to run on single chip – or,
worse, in software – on the Pi, but because the CISC
architecture of x86 can take many more shortcuts than
Arm’s RISC layout.
Speaking of which, the Pi’s architecture restrictions
haven’t changed: Any software you run needs to be
compatible with and compiled to run on Arm.
Thankfully, there’s a large library out there, and it’s often
possible (though slow) to build your own packages from
source, if there’s no Arm version available.

Get the hardware right
If you’re going to use a Raspberry Pi 4 as a desktop PC,
you need to make a choice: do you opt for 1GB RAM
(no), 2GB (possibly), or the most expensive Pi 4 build at
4GB? The latter does seem sensible.
Next, controlling the thing. Peripherals aren’t really a
huge issue, even if they use heavy-drawing RGB LEDs,
because the Pi 4 uses a 3A power supply. The Pi 4 has
switched its power input from micro USB to USB-C, and
unfortunately this new port is not USB-C compliant. So
if you use a fancy a smart charger, it probably won’t
power the device, and might possibly damage it. You
won’t run into these issues if you use the official

Run the best Pi 4 OS


It’s been around since June 2019, but it’s well worth checking out


the new, desktop-capable Pi on the block.


N


OTHER DISTROS


There are a number of other Pi distros that aren’t yet supported/
don’t work on Pi 4, but are nonetheless noteworthy. Fedora currently
provides ARMv7 and AArch64 builds, but until Pi 4 kernel fixes are
upstreamed there’s no official Pi 4 support. Similarly, FreeBSD
should get a Pi 4 version in time. The Raspberry Pi has long been the
home of the resurrected RISC OS, which comes from Arm roots on
the Acorn Archimedes, but a 64-bit version specifically for the Pi 4
would be a huge surprise – there has not, thus far, been any 64-bit
release of RISC OS for any platform, and it would mean a major
rewrite of the code.
However, there’s nothing stopping you trying a 32-bit version. It’s
not as though the ARMv8 processor can’t handle it. You lose access
to some of your RAM if you’ve gone for the 4GB version, and many
distros lack support for some of the Pi 4’s functionality, but this is a
platform based on experimentation. Continuing the retro trend, if
you yearn for the simplicity of the Commodore 64, check out
Combian64 (https://cmaiolino.wordpress.com). Leave a comment
on the blog if you’d like the developer (Carmelo Maiolino) to consider
making a Pi 4 build. If you identify more with the 16-bit generation,
Amibian (https://gunkrist79.wixsite.com/amibian) is worth a look.

Raspbian’s bespoke
PIXEL desktop
environment is
light and fast,
especially so
on the Pi 4.

‘Member RISC OS, ‘member filenames beginning with exclamation
marks, ‘member those weird three button mice?

34 LXF260March 2020 3332March 0Sens2i0e

Raspberry Pi projects


ewhardwareisveryexciting,andthenatural
responsetoaspiced-upPiwouldbetoabuseit
tothemax.SowhynotuseitasafullPC?Yes,
ithasalwaysbeentechnicallypossibletouseaPiasa
functioningdesktopPC.EventheRaspberryPi 1 Model
B,withits512MBRAMand700MHzARMv6CPUcould
managearudimentarydesktop,inmuchthesameway
asyoucanforceaCommodore 64 torunaGUIoreven
aLinuxanalogifyou’recrazy.Ofcourse,thosewithlong
memorieswillrememberPCsofyesteryearrunningwith
farlighterspecs,buttheyweren’tthesizeofacredit
card,withaseverelylimitedarchitecture.
Whilethere’sbeenincrementalimprovementinthe
Pi’sdesktopperformanceovertheyears,thenew
hardwareinthePi 4 doesawaywiththe“technically
possible”partoftheequation:itisnotjustfeasibleto
runaPi 4 asadesktopmachine,itispositively

pleasurable,somuchsothattheRaspberryPi
FoundationissellingitsownRaspberryPidesktopkit.
Thatnewprocessorhasenoughmuscletoflingaround
whateveryoumightthrowatit.NetworkandUSBno
longersharethesamebus,therearemultiplemonitor
outputsonboard,and(dependingonthe spec you pick)
your desktop OS can access up to 4GB RAM. Usually.
There are some caveats for the over-excited, before
we get too involved. This will never replace your high-
end desktop machine. That would be preposterous – it’s
a $55 bundle of electronics, not a $1,000 killer rig.
Realistically, unearthing old desktop hardware and
slapping some variety of Linux on it will offer a much
more capable and flexible experience. This isn’t only
because that hardware is typically much faster, with
functions that are given to dedicated hardware on
traditional PCs forced to run on single chip – or,
worse, in software – on the Pi, but because the CISC
architecture of x86 can take many more shortcuts than
Arm’s RISC layout.
Speaking of which, the Pi’s architecture restrictions
haven’t changed: Any software you run needs to be
compatiblewithandcompiledtorunonArm.
Thankfully,there’salargelibraryoutthere,andit’soften
possible(thoughslow)tobuildyourownpackagesfrom
source,ifthere’snoArmversionavailable.

Getthehardwareright
Ifyou’regoingtouseaRaspberryPi 4 asadesktopPC,
youneedtomakeachoice:doyouoptfor1GBRAM
(no),2GB(possibly),orthemostexpensivePi 4 buildat
4GB?Thelatterdoesseemsensible.
Next,controllingthething.Peripheralsaren’treallya
hugeissue,eveniftheyuseheavy-drawingRGBLEDs,
becausethePi 4 usesa3Apowersupply.ThePi 4 has
switcheditspowerinputfrommicroUSBtoUSB-C,and
unfortunatelythisnewportisnotUSB-Ccompliant.So
ifyouuseafancyasmartcharger,itprobablywon’t
powerthedevice,andmightpossiblydamageit.You
won’trunintotheseissuesifyouusetheofficial

Run the best Pi 4 OS


It’s been around since June 2019, but it’s well worth checking out


the new, desktop-capable Pi on the block.


N


OTHERDISTROS


ThereareanumberofotherPidistrosthataren’tyetsupported/
don’tworkonPi4,butarenonethelessnoteworthy.Fedoracurrently
providesARMv7andAArch64builds,butuntilPi 4 kernelfixesare
upstreamedthere’snoofficialPi 4 support.Similarly,FreeBSD
shouldgetaPi 4 versionintime.TheRaspberryPihaslongbeenthe
homeoftheresurrectedRISCOS,whichcomesfromArmrootson
theAcornArchimedes,buta64-bitversionspecificallyforthePi 4
wouldbeahugesurprise–therehasnot,thusfar,beenany64-bit
releaseofRISCOSforanyplatform,anditwouldmeanamajor
rewriteofthecode.
However,there’snothingstoppingyoutryinga32-bitversion.It’s
notasthoughtheARMv8processorcan’thandleit.Youloseaccess
tosomeofyourRAMifyou’vegoneforthe4GBversion,andmany
distroslacksupportforsomeofthePi4’sfunctionality,butthisisa
platformbasedonexperimentation.Continuingtheretrotrend,if
youyearnforthesimplicityoftheCommodore64,checkout
Combian64(https://cmaiolino.wordpress.com).Leaveacomment
ontheblogifyou’dlikethedeveloper(CarmeloMaiolino)toconsider
makingaPi 4 build.Ifyouidentifymorewiththe16-bitgeneration,
Amibian(https://gunkrist79.wixsite.com/amibian)isworthalook.

Raspbian’s bespoke
PIXEL desktop
environment is
light and fast,
especially so
on the Pi 4.

‘Member RISC OS, ‘member filenames beginning with exclamation
marks, ‘member those weird three button mice?
Free download pdf