Raspberry Pi Can Now Run Quake 3 On Open Graphics

[FishB8]

How would you chroot into an ARM userspace on a x86 machine?

Build static qemu, register it under binfmt.d. Create disk image for ARM with a working system. Mount the image. Make sure to copy static qemu to the same path in the chroot environment. Recursive-bind mount /dev /proc /sys into chroot image. Chroot into image and build ARM stuff. Unmount image and write it to RPi Card.

You would have to run a full ARM CPU emulation, which can by definition not use hardware virtualization on a x86 CPU, making it slower than the real hardware.

Lack of hardware paravirtualization is irrelevant. Full emulation of ARM on x86-64 is still way faster that native ARM. I compiled a full version of gcc-4.8.2 on RPi. It took almost 36 hours. Took roughly 45 min in qemu-userspace. Not as fast as cross-compiling, but try cross-compiling something like perl or python using a cross-compiler without developing a strong urge to shoot yourself.

[Luke_Wolf]

How would you chroot into an ARM userspace on a x86 machine? You would have to run a full ARM CPU emulation, which can by definition not use hardware virtualization on a x86 CPU, making it slower than the real hardware.

You're forgetting that while that would be true if the CPU in the Raspberry pi's processing power were anywhere close to x86 desktop hardware, the difference in power of the hardware is so vast that the performance of the x86 machine outstrips the hit for running without hardware virtualization.

[Chewi]

Forget QEMU. Assuming you already have the toolchain, cross-compiling the kernel is almost as easy as natively compiling it. It's nowhere near as problematic as cross-compiling userspace stuff.

Also, avoid GCC 4.8 until 4.8.3 comes out, unless you know that it's been patched. This bug produces really unstable ARM kernels that crash all over the place and have the potential to totally screw up your filesystem. It happened to me.

[Vim_User]

You're forgetting that while that would be true if the CPU in the Raspberry pi's processing power were anywhere close to x86 desktop hardware, the difference in power of the hardware is so vast that the performance of the x86 machine outstrips the hit for running without hardware virtualization.

Would be nice to see some benchmarks comparing the processing power. Anyone that owns a Pi willing to compare it with Qemu emulating the Pi CPU?

[Vim_User]

Build static qemu, register it under binfmt.d. Create disk image for ARM with a working system. Mount the image. Make sure to copy static qemu to the same path in the chroot environment. Recursive-bind mount /dev /proc /sys into chroot image. Chroot into image and build ARM stuff. Unmount image and write it to RPi Card.

It would still have to emulate the ARM CPU, which should be significantly slower.