Raspberry Pi 3 - 64 Bit Operation

[NeddySeagoon]

Team,

I'm trying to get a Raspberry Pi 3 to work in 64 bit mode. I've got lots of bits to put together, including some userspace things in a cross root.
So far I have

a 3.3v USB to serial 'dofer'
a 64 bit Pi3 uboot
a 64 bit Pi3 kernel

The idea being that uboot leaves the Pi in the right privilege level for the kernel to run and hands over to the kernel.
I get to interact with the Pi using minicom because thats about all that works in 64 bit mode so far.

I'm building as much userspace as possible with a cross dev toolchain. However one of the key packages - gcc fails.
The build log finishes with

[schorsch_76]

Could you provide the kernel config and the uboot?

I would try to get a RPi3 buildroot image. There is nearly perfect cross compile support in it. With that staging point in 64 bit aarch userland we could get a 64bit gcc on gentoo
_________________
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Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage

[NeddySeagoon]

schorsch_76,

I'm following the instructions on the Raspberry pi forum.
I've just found that there is a gotcha or two with the serial console too.
Serial was ever thus :) It may not matter in 64 bit mode though.

As I say, I've only built stuff so far. I've not actually tested anything yet.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[schorsch_76]

I git now the 64 bit kernel booting following the mentioned thread in the raspberry forum. But it still panics because of no userland Now i try to setup the buildroot image with an gcc in it. Video and audio is not yet working. All over serial line

[NeddySeagoon]

schorsch_76,

Well done. I only get as far as

[schorsch_76]

So, i got the buildroot userland running

[schorsch_76]

My uboot environment is:

[schorsch_76]

The explanation is more useful i think, but i leave the listing abouve for completeness:

I added in the u boot console

[NeddySeagoon]

schorsch_76,

I had console=tty1 in my cmdline.txt but everything else was correct, including the serial port set up.
I also had too many zeros in the kernel load address.

The other difference is I get

[schorsch_76]

The explanation above creates it.
_________________
// valid again: I forgot about the git access. Now 1.2GB big. Start: 2015-06-25
git daily portage tree
Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage

[NeddySeagoon]

schorsch_76,

[schorsch_76]

You are welcome Neddy! You helped me more than once.

I try to build the native gcc for aarch64. buildroot bropped the target gcc about 2012. Now i try to cross compile the native aarch gcc ....
_________________
// valid again: I forgot about the git access. Now 1.2GB big. Start: 2015-06-25
git daily portage tree
Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage

[schorsch_76]

I got a pure C compiler cross compiled. I always failed at the c++ lib stage.

I used that script that i copied from [1] and i adjusted it slightly:

[NeddySeagoon]

schorsch_76,

I can't get past the login prompt with my userland but adding init=/bin/bash to bootargs gets me a shell, so I'm "in", sortof.
Anyway, I can poke around from the inside now.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[schorsch_76]

I had a similar issue as i tried the debian aarch64 userland. pam failed. So i switched to buildroot. I tried the usual /etc/shadow thingie (wiki raspberry pi) but it didnt work.

Is your userland gentoo?

How about using your gentoo userland and my "cross gcc" to emerge the gcc?
_________________
// valid again: I forgot about the git access. Now 1.2GB big. Start: 2015-06-25
git daily portage tree
Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage

[NeddySeagoon]

schorsch_76,

I don't have pam at all. The make.conf that comes free with crossdev has
USE=-pam set.

My part of a userland was obtained by using crossdev to build a aarch64-armv8a-linux-gnueabi cross toolchain then blindly using it to build @system in an empty target root.
Actually in /usr/aarch64-armv8a-linux-gnueabi/. Since I've not done anything special, except keyword a few packages, its done fairly well.

Maybe setting the profile to

[schorsch_76]

Hi Neddy,

i try this today evening.
_________________
// valid again: I forgot about the git access. Now 1.2GB big. Start: 2015-06-25
git daily portage tree
Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage

[NeddySeagoon]

schorsch_76,

I have a working cross gcc and cross c++ and all the other good things built using crossdev.
They all seem to work.

Those programs run on an amd64 and produce code for aarch64-armv8a-linux-gnueabi using the files in /usr/aarch64-armv8a-linux-gnueabi/etc/portage.
This is all normal Gentoo but with the cross compiler twist.

I see how your script builds you a cross tool chain that ends up in

[schorsch_76]

Now i got everything on the SD card and logged into it. gcc is on it. Now it tries to compile m4/flex/bison/gcc.

It got a 1 GB swap file ... Hopefully it will succeed. I press my thumbs ...

M4/flex just got compiled. Good sign

https://www.schorsch-tech.de/lib/exe/fetch.php?media=linux:rpi3-compiles.png

@Neddy: You are a genius about cross compiling gentoo! I tried this too but failed (thus buildroot)
_________________
// valid again: I forgot about the git access. Now 1.2GB big. Start: 2015-06-25
git daily portage tree
Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage

[schorsch_76]

The script i posted a few das ago needs a cross compiler from cross dev (host: amd64 target: aarch64). In fact, This script cross compiles a compiler for the target that it can natively compile "Cross compiling a native compiler"

The "--host" in the configure steps specifies that host the target will run. See my /opt/cross/bin/gcc

In fact, i set /"opt/cross" owned by my regular user to make sure the aarch64 dont get mixed up with my other cross compiler in /usr. So i compiled the "/opt/cross" as normal user and installed it as normal user. It only runs on aarch64 not on my amd64 host. I havemt known about sysroot .. though .... /opt/cross later copied to the RPi3

[NeddySeagoon]

schorsch_76,

After some 'faffing' about, I have the portage tree, the sources for gcc and your native armv8 gcc on my Pi.

If I can get emerge to use your gcc, my plan is to

[schorsch_76]

Yes, i put the distfiles to the sdcard like you. That emerge grabbed my new gcc i exported "CC=/opt/cross/bin/gcc" Flex/Bison/m4 were compiled by this gcc and they work.

The unpacking stage took for me about 20 to 30 min. At the configure stage it failed at a type check for int64_t ...

So i tried yesterday various Versions of gcc and libs to "cross compile the compiler" but they all failed at the libstdc++3 stage at "vnsprintf" (dont habe the error currently here). I am up to fill a bug report on gcc.gnu.org/bugzilla.

The check for int64_t on the target is strange too ... that this fails ....
_________________
// valid again: I forgot about the git access. Now 1.2GB big. Start: 2015-06-25
git daily portage tree
Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage

[schorsch_76]

@neddy: I Thing the correct target triple for aarch64 is:
aarch64-linux-gnu

See:
https://www.gnu.org/software/autoconf/manual/autoconf-2.65/html_node/Specifying-Target-Triplets.html

and in Debian they name it aarch64-linux-gnu too.
https://wiki.debian.org/Arm64Port

[schorsch_76]

The error, that occours when i try to "cross compile the native compiler" for aarch64 is always:

[schorsch_76]

Bug to gcc submitted:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70464
_________________
// valid again: I forgot about the git access. Now 1.2GB big. Start: 2015-06-25
git daily portage tree
Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage