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64-bit ARM Kernel Development Demo on a Nexus 9

89 points| andreiw | 11 years ago |osdevnotes.blogspot.com | reply

36 comments

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[+] andreiw|11 years ago|reply
A short demo showing that your Nexus 9 is actually the cheapest and most accessible 64-bit ARM development platform for systems programming.
[+] voltagex_|11 years ago|reply
I got pretty sick of "Linux on xyz Android device" meaning a chroot with varying levels of usefulness. This is the first post in a while that shows some actual low-level dev work being done.

How difficult would it be to get a (mainline?) kernel booting on this, maybe even into Debian?

[+] pjmlp|11 years ago|reply
There are lots of cheap boards out there, way cheaper than a Nexus, of course they require a bit of electronics knowledge, but that should be part of any proper CS degree (at least mine had it).
[+] hobo_mark|11 years ago|reply
Gorgeous! I know I'm asking for much but does it have JTAG debug access to the CPU as well?
[+] higherpurpose|11 years ago|reply
> It's unclear if the "oem unlock" allows reflashing custom unsigned firmware.

I don't think it does. I think you usually need "root" to install another ROM/OS on the device as well.

[+] andreiw|11 years ago|reply
The oem unlock allows you run a custom OS (e.g. a custom Android build) that is not signed. This is well known, and is what allows this demo to work. However, the comment I was making is whether the firmware (i.e. the bootloader, "BIOS" if you may - in particular the Secure OS) can be reflashed.

The reason the existing firmware could be desired to be replaced is that the Secure OS component specifically disallows an OS to run in hypervisor mode (i.e. no KVM or Xen), or because of terrible bugs in HBOOT that cause hangs if the boot.img exceeds a certain arbitrary size (a few tens of MB). All these limitations mean that even an OEM-unlocked device is not quite entirely available to the mercy of a developer.

Of course, the ability to reflash the low-level boot code is not very useful unless you have sources to build a better replacement.

[+] lancemjoseph|11 years ago|reply
Are there any devices that ship with Android that could be reflashed to support a Linux kernel with KVM or Xen bits? Either Intel Atom or ARM-based devices?