On Sat, Apr 25, 2020 at 4:31 AM Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 4/24/20 10:52 PM, Tom Rini wrote:
On Fri, Apr 24, 2020 at 05:46:43PM -0300, Mitchell Horne wrote:
On Fri, Apr 24, 2020 at 1:52 PM Tom Rini trini@konsulko.com wrote:
On Mon, Apr 20, 2020 at 06:34:11PM -0400, mhorne@FreeBSD.org wrote:
From: Mitchell Horne mhorne@FreeBSD.org
FreeBSD makes use of u-boot's CONFIG_API to provide a version of its standard bootloader for embedded architectures. This series adds the necessary support for the RISC-V architecture, along with some small fixes to the API demo program for 64-bit systems.
Adding in the RISC-V maintainer and EFI maintainer. I thought the intention was for OSes to use the EFI loader here, even for "embedded" ? Thanks!
Hi Tom,
You are right, EFI is preferred. FreeBSD's loader has two implementations on arm: one that is an EFI application, and one based on this u-boot API (known as "ubldr"). ubldr precedes the EFI implementation by a few years.
For RISC-V my intention is also to implement both versions, and ubldr was simpler on FreeBSD's side, so I chose to do that first. Do you think this series is still worth pursuing if u-boot is going the way of EFI?
In my mind at least, the EFI interface is preferred as it's a defined external standard interface. If the architecture maintainers want to support both the U-Boot API and EFI on RISC-V, I don't object. But one of the intentions is to have there be less work for OS folks to have to do for example. So that you found this a good first step for your use case means perhaps we need to continue to have the U-Boot API method be around (not that we had planned any sort of removal). Thanks!
Hello Mitchell,
let me just give me an overview of where we currently are with UEFI support for RISC-V:
U-Boot supports UEFI to the point that we can start GRUB as EFI binary.
In Linux the UEFI support for RISC-V is being set up, cf. https://lkml.org/lkml/2020/4/20/1800
In EDK2 RISC-V support is under active development (https://edk2.groups.io/g/devel/search?q=RISC-V). In EDK2's staging repository (https://github.com/tianocore/edk2-staging.git) you can find a branch RISC-V-V2-CI-log-all-archs.
One challenge is the transfer of the HART id which is used for booting. In U-Boot this has been addressed by the patch 5370478d1c7a ("riscv: Add boot hartid to device tree").
Hi, just so this thread isn't left dangling, I eventually went the EFI route. I found this to be easier because the hart-id fixups aren't applied when executing plain binaries via the "go" command. I don't think this patchset will be needed. Thanks!
Mitchell
@Atish: Is there a corresponding patch for EDK2?
Best regards
Heinrich