Cross-compiling for Raspberry Pi on Ubuntu
While the Raspberry Pi 2 has four cores to churn through code, it still takes longer to compile than on most workstations and laptops. If you are feeling adventurous, you can try cross-compiling which has become easier to set up and get working.
Cross-compiling is when binaries created are for another target architecture than the one you are compiling on. This kind of set up is very typical when creating Android applications. The end result is that you can take the resulting binary and place on its target platform, and it will run there.
There are even tricks to getting the cross-compiled binary to also run on your native system!
In this guide, I’ll walk you through:
- Setting up a cross-compile toolchain in Ubuntu (15.04 Vivid)
- Setting up the proper exports
- Compiling a test program for your native and target armhf platform
- Compiling the latest Raspberry Pi 2 kernel with VC4 support.
Wireless BCM4312 with the 3.10, 3.11, 3.12 and 3.13 kernels
The hybrid driver from Broadcom was updated again in September (2013) with all the previous patches and a few other fixes as well. This brings them up to support linux kernel 3.9, which is very much welcome.
Sadly it breaks again with >= 3.10 with many warnings and errors which isn’t good considering that Ubuntu (13.10) Saucy Salamander is about to be released.
We do have a patch for you though that gets us working again up to the 3.11 kernel.
Chipsets supported by “Broadcom’s IEEE 802.11a/b/g/n hybrid Linux® device driver” are: BCM4311, BCM4312, BCM4313, BCM4321, BCM4322, BCM43224, BCM43225, BCM43227 and BCM43228.
Wireless BCM4312 with the 3.6, 3.7 and 3.8 kernel
As a follow up to , I’ve also tested the Broadcom hybrid driver with the 3.6, 3.7 and the soon to be released 3.8 kernels with success. There have been no major changes that should effect the operation of this driver.
To verify that everything is working as expected on the software side, when modprobe or insmod wl, you should get a similar dmesg output:
[ 307.560347] lib80211: common routines for IEEE802.11 drivers
[ 307.560353] lib80211_crypt: registered algorithm ‘NULL’
[ 307.564524] wl: module license ‘unspecified’ taints kernel.
[ 307.564529] Disabling lock debugging due to kernel taint
Wireless BCM4312 with the 3.4 and 3.5 kernel
The hybrid driver from Broadcom is still a bit behind in terms of support for the latest kernels but there are workarounds. This particular issue also effects other kernel modules such as the out of tree Nvidia and ATI blobs that require the asm/system.h file in their includes.
I’ve had success with replacing it with asm/switch_to.h which seems to have fixed things for now. The cause for this can be found on the LKML.
Chipsets supported by “Broadcom’s IEEE 802.11a/b/g/n hybrid Linux® device driver” are: BCM4311, BCM4312, BCM4313, BCM4321, BCM4322, BCM43224, and BCM43225, BCM43227 and BCM43228.
Doing battle with a Dell R620 and Ubuntu
We recently got sent a Dell R620 to evaluate and while its technical specification is amazing there are a few things that need to be handled first.
As far as Ubuntu and the Dell R620 go, Precise (12.04) is the only way to go here. Every release before Precise has issues with this hardware in one way or another. This is new hardware of after all.
For our “use case” we downgraded the PERC H710P controller to a H310 controller so we can have direct access to the drives via pass-through. The H310 allows TRIM support for SSDs and SMART data via smartctl to be used without any problems. If you are interested in SMART information and PERC H700 series RAID controller, I posted about possible workarounds at Dell’s customer support site.
