64-bit Tiano Core UEFI for the Raspberry Pi 3

https://github.com/andreiw/RaspberryPiPkg

by Lwrless • 8 years ago

67 24 8 years ago

Quequau• 8 years ago

My understanding is that one of prerequisites of CoreOS is UEFI. The last time I checked there wasn't much support for CoreOS on Raspberry Pi, so I wonder if this might help.

andreiw9• 8 years ago

Maybe. I'll look.

floatboth• 8 years ago

Is there much need for the big ass TianoCore? FreeBSD uses U-Boot's tiny implementation successfully, it even supports netbooting

my1232• 8 years ago

Booting Windows doesn't work with the U-Boot impl currently

Vogtinator• 8 years ago

That can be fixed.

rwmj• 8 years ago

edk2.aarch is a 2 MB binary, which — while I'm sure it's bigger than uboot — isn't exactly big compared to any modern SD card.

I'd be interested to know what the memory footprint is like. I don't have an easy way to measure it.

andreiw9• 8 years ago

If you run the “mmap” command in UEFI shell, and count the memory regions marked as Runtime Code and Runtime Data, that will give you the total resident (after booting OS) memory footprint.

Note that these numbers will also include Arm Trusted Firmware and firmware tables.

pritambaral2• 8 years ago

Not for regular purposes of booting Raspbian, or just a standard Linux kernel(+initramfs). In fact, even u-boot is not needed to boot Linux, because the RPi firmware is designed to boot Linux. FreeBSD uses u-boot because otherwise it'd have to implement Linux's conventions for booting, and it's just simpler to chainload via u-boot since u-boot already implements that.

andreiw9• 8 years ago

RaspberriPiPkg can’t boot Raspbian today, since the latter is 32-bit. Can boot stock 64-bit SUSE and Ubuntu, though.

andreiw9• 8 years ago

Author here.

If you wanted to run you own drivers, or had code written specifically against protocols exported by Tiano components I believe the answer is - yes.

RaspberryPiPkg is the $35 64-bit Arm UEFI devkit.

Of couse the U-boot implementation of UEFI spec is getting better and better day by day, and that’s obviously awesome. I am sure someone will add ACPI support to it any day now. Having choice is good, and I wouldn’t want to live in a world with a single implementation. That said, Tiano (like it or not) /is/ the reference implementation, and you’re much less likely to run into surprises (today). Notice how I didn’t say Tiano is /better/, because in a number of ways (code quality, complexity, fragmentation) it’s pretty awful.

One thing the U-boot implementation excels at is embedded Arm board support - U-boot is the defacto firmware for most embedded hardware, and now all of that hardware is EFI-capable. Porting Tiano is effort you don’t want to spend.

That said, there are hybrid approaches - EFIDroid (efidroid.org) runs Tiano on top of LK, using LK’s platform support for drivers.

fao_3• 8 years ago

TianoCore was a horrible implementation of UEFI. When I used it to code against it had several standard-divergent parts.

wolfgke2• 8 years ago

Can you give details?

andreiw9• 8 years ago

A lot of it really is code quality issues, both in the core and some of the contributed I/O drivers.

fao_3• 8 years ago

The specific problems I had I don't entirely remember (It was around 3 - 4 years ago at this point). The bug I encountered was relating to escaping the UEFI environment. My code was written to the UEFI 2.6 standards document, and it turns out that TianoCore diverged from that document with relation to how memory allocation was dealt with, and how setting up the post-boot environment was done.

EDIT: I think that it was something along the lines of some implementations (including TianoCore) required the ExitBootServices call to be performed more than once to exit the UEFI-controlled environment correctly? Even after doing that I had some problems with it.

andreiw9• 8 years ago

Author here, feel free to AMA.

znpy• 8 years ago

Can it netboot?

andreiw9• 8 years ago

Not yet... the good news is that iPXE supports the SMSC USB NIC on the Pi. I don't know if iPXE will work out of the box, but I certainly intend on porting the iPXE NIC driver as a standalone (and GPL-licensed, of course) SNP implementation so you can use it with UEFI's own PXE implementation or anything else (like, shudder, it's shitty network tools...).

The biggest possible barrier to that today, which is still unknown, is the quality of the USB host controller. NICs use bulk, but there's no guarantee that the host controller driver is good enough. Time will tell, I suppose...

64-bit Tiano Core UEFI for the Raspberry Pi 3

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