Gentoo Forums

dr_wulsen wrote:I've tried an armv8-hardfloat-linux-gnueabi. don't do it, the /proc/cpuinfo gives (falsely) an armv7.
all python packages would look for a armv7 gcc and fail to build....

schorsch_76 wrote:If you want to compile for 64 bit, use: aarch64-unknown-linux-gnu
This was recommended on the gcc bugzilla and [post=7900188]verified by Neddy[/post] in the [topic=1041352]Raspi3 64 Bit thread[/topic].

keet wrote:According to the Mesa site, the current Mesa, as well as Linux kernel 4.5 (and the Raspberry Pi Foundation's tree of 4.1) includes support for VC4. Hopefully this will mean less trouble building packages that depend on Mesa and more ease building and running programs that use or depend on hardware video acceleration.[/url]

vastchen wrote:somebody know Pi3 how to config /etc/portage/make.conf
Pi 2 CFLAGS="-02 -pipe -march=armv7-a -mfpu=vfpv3 -mfloat-abi=hard "
can use this ??? Pi 3 CFLAGS="-02 -pipe -march=armv8-a -mfpu=vfpv3 -mfloat-abi=hard " ??

-march= -mtune=cortex-a53 ?????

somebody can put you pi3 /etc/portage/make.conf to see?

vastchen wrote: I found somebody use armv7 somebody use armv8 what should be use ? I will crazzy , if i want pi2 distccd with pi 3 use crossdev -t “？”

CFLAGS="-march=armv8-a+crc -mtune=cortex-a53 -mfpu=crypto-neon-fp-armv8 -mfloat-abi=hard -ftree-vectorize -funsafe-math-optimizations -O2 -pipe"

keet wrote:

vastchen wrote: I found somebody use armv7 somebody use armv8 what should be use ? I will crazzy , if i want pi2 distccd with pi 3 use crossdev -t “？”

I have been using this with no apparent problems:

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CFLAGS="-march=armv8-a+crc -mtune=cortex-a53 -mfpu=crypto-neon-fp-armv8 -mfloat-abi=hard -ftree-vectorize -funsafe-math-optimizations -O2 -pipe"

dr_wulsen wrote:

das_morph wrote:

dr_wulsen wrote: If anyone is interested in my custom .config for the raspberrypi-sources-4.4 to have a starting point for their own kernel, let me know - I will then post them here.

I'd be interested, since I can't seem to get the wifi to work on my pi. Might be missing some kernel modules or something. Which sources are you using for the 4.4 kernel? I tried the raspberrypi-sources package, but neither using crossdev nor native compiling with distcc resulted in a working kernel. The github sources work for me.

Hi das_morph,
I'm using the raspberrypi-sources-4.4.9999 in the portage tree, which actually downloads the github sources.
One thing I've stumbled across was that the simple zImage wouldn't work for me, if just renamed to kernel7.img, but had to use the include mkknlimg.
That's my kernel compile script:

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#!/bin/bash
ARCH=arm CROSS_COMPILE="/usr/bin/armv7a-hardfloat-linux-gnueabi-" make -j5 zImage modules dtbs
mkdir /tmp/rpi3
mkdir /tmp/rpi3/overlays
./scripts/mkknlimg arch/arm/boot/zImage /tmp/rpi3/kernel7.img
cp ./arch/arm/boot/dts/*.dtb /tmp/rpi3
cp ./arch/arm/boot/dts/overlays/*.dtb* /tmp/rpi3/overlays
cp ./arch/arm/boot/dts/overlays/README /tmp/rpi3/overlays
cp .config /tmp/rpi3/kernelconfig

I have sent the config to you via PN.
Of course, you will need the two files named in my earlier post.

safeness wrote:

dr_wulsen wrote:

das_morph wrote:

dr_wulsen wrote: If anyone is interested in my custom .config for the raspberrypi-sources-4.4 to have a starting point for their own kernel, let me know - I will then post them here.

I'd be interested, since I can't seem to get the wifi to work on my pi. Might be missing some kernel modules or something. Which sources are you using for the 4.4 kernel? I tried the raspberrypi-sources package, but neither using crossdev nor native compiling with distcc resulted in a working kernel. The github sources work for me.

Hi das_morph,
I'm using the raspberrypi-sources-4.4.9999 in the portage tree, which actually downloads the github sources.
One thing I've stumbled across was that the simple zImage wouldn't work for me, if just renamed to kernel7.img, but had to use the include mkknlimg.
That's my kernel compile script:

Code: Select all

#!/bin/bash
ARCH=arm CROSS_COMPILE="/usr/bin/armv7a-hardfloat-linux-gnueabi-" make -j5 zImage modules dtbs
mkdir /tmp/rpi3
mkdir /tmp/rpi3/overlays
./scripts/mkknlimg arch/arm/boot/zImage /tmp/rpi3/kernel7.img
cp ./arch/arm/boot/dts/*.dtb /tmp/rpi3
cp ./arch/arm/boot/dts/overlays/*.dtb* /tmp/rpi3/overlays
cp ./arch/arm/boot/dts/overlays/README /tmp/rpi3/overlays
cp .config /tmp/rpi3/kernelconfig

I have sent the config to you via PN.
Of course, you will need the two files named in my earlier post.

@dr_wulsen: Can you send me your config as well?

Thanks!

NeddySeagoon wrote:dr_wulsen,

That kernel emulation option generates code to deal with the illegal instruction exceptions programs built with SWP/SWPB instructs may generate when running on a CPU that is missing SWP/SWPB. Rather like the kernel software floating point option for 386/486SX CPUs that had no hardware floating point.
This is slow and horrible as there will be a user space to kernel space context switch when the illegal instruction exception is raised. The kernel will emulate the instruction, then there will be a kernel space to user space context switch back to the program to the instruction following the illegal instruction. Execution in userspace continues as if nothing had happened.
Consider the effect of this when a SWP is used in a loop ...

The problem here is

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{standard input}:134: Error: swp{b} use is obsoleted for ARMv8 and later 

that gcc is generating these instructions and passing them to the assembler, which then objects.

There may be a gcc/assembler option (CFLAG) to allow these instructions to be compiled. If so, and this works, you will need that kernel option if SWP/SWPB is not implemented in the Pi 3 CPU.

NeddySeagoon wrote:You will find Pi3_64_bit_root.tbz2 and Pi3_64_bit_boot.tbz2 at http://grytpype-thynne.org/~roy/Pi3_64bit/
They are the partition2 (ext4) and partition1 (vfat) copied from my SDCard.

NeddySeagoon wrote:Throwaway content gets journaling off.