Enable full memory for 512MB Rev 2.0 Pi

I downloaded the latest kernel images from GitHub, I'm currently running the arm448_start.elf.

Actual current capture of top -d 0

I suspect it's just a logistics problem that rpi-update will fix sooner or later.

I haven't tried myself yet, but it should really just be bootcode.bin/loader.bin/start.elf that needs changed.  Probably not a good idea to use arm448_start.elf on a 256Mb board though, so it'll just be a case of identifying the board before giving you the option of what ones to pick.

I was half expecting some of the problems behind the recent posts on 512Mb doa's to be something daft like the old firmware not booting on the new board for some reason, but that doesn't appear to be the case.

Anyway, I'd definately recommend going the github route along with a self compiled kernel from the github source for a few good reasons:

1. you learn something new
2. you become independent of problems, or simply stuff like rpi-update not keeping up
3. you get to pick the bits you need - no more missing wifi drivers etc

If you try to use any of the new images on the 256MB it won't boot. Yes the process is simple, just copy whatever image you want to boot to start.elf and reboot. I only tested the 448/64MB memory split.

I've read some of the reports of issues with the 512MB, some of them smell more like a hardware/assembly issue.

If you want to do some kernel development/building I'd strongly recommend you setup your development environment in a separate Linux machine.

My 512MB rev. 2 boots just fine with a 256MB Raspian image. It only shows 192 MB, but it does boot.

I think what jamodio is saying is that if you have an sd-card setup for 512Mb - i.e. with arm448_start.elf copied to start.elf - then it won't boot on a 256Mb Pi.

256Mb card on a 512Mb Pi works ok as you've found..

jamodio wrote:

 

If you want to do some kernel development/building I'd strongly recommend you setup your development environment in a separate Linux machine.

Well yes. Assuming you have one.  Kernel compiling on the Pi itself is not for those short on patience

With crosstool-ng it's a fairly painless process to setup a kernel dev environment on an x86 linux system these days.

Correct, and I confirmed it when I screwed up and via a serial console session I copied the 448 image to start.elf when I was connected to the wrong Rpi :-)

No, he says it won't boot. I take that to mean exactly what it says.

Gary Stewart wrote:

 

No, he says it won't boot. I take that to mean exactly what it says.

Well he actually said:

If you try to use any of the new images on the 256MB it won't boot.

I take that at face value. My reading of it is 'if you try to use any of the new (512Mb start.elf firmware) images in the 256Mb (physical Pi) it won't boot'

I don't believe I'm reading anything into it that isn't there ?

Lets clarify that by "new images" I meant the new ones created for the 512MB board.

The previous images for the 256MB board run OK on the 512MB, but you are not going to realize any benefits from the extra memory if you don't use one of the new kernels with the memory splits for the 512MB.

I guess that sooner or later we'll see a new distro where a 256MB image gets run first to enable running raspi-config where it can read cpuinfo and offer the option to change the memory splits now including the ones for 512MB boards.

Didn't see any comments about when such update to the distro may be available.