On 17/01/2017 20:57, Warner Losh wrote:
On Tue, Jan 17, 2017 at 12:47 PM, Emmanuel Vadot manu@bidouilliste.com wrote:
Hi Alexander,
On Tue, 17 Jan 2017 20:36:59 +0100 Alexander Graf agraf@suse.de wrote:
On 17/01/2017 16:50, Emmanuel Vadot wrote:
This series of patches add the needed bits for booting the FreeBSD loader and kernel. FreeBSD loader and kernel needs the U-Boot API and dcache/icache flushed for it to run so add this operation in go/bootelf command and when closing the API. Also add some some boot command that locate and run the FreeBSD loader if found.
Is there any particular reason the EFI boot path doesn't work for you?
Configuring u-boot differently to be able to boot FreeBSD sounds a bit strange to me.
Alex
EFI works fine for us, that's what we use for arm64 (pine64/rpi3 for example) because we want to only use EFI for arm64. For armv6/v7 we have legacy devices etc ... and even if EFI works (well honestly I have to fix our smbios code for it to work properly) we need to be able to boot without EFI support. With this series of patches is an EFI binary is found this is the one that would be loaded, so when the times comes we could make our releases with EFI bootloaders for ARM. In the meantimes we still need the U-Boot API for our loader.
In addition, we have a long-term support branch (FreeBSD 11.x) that we need to support with the current setup since we use u-boot to load our tertiary loader which loads the kernel and related files (hence the need for the u-boot app API). It's something that's evolved over a number of years without proper upstreaming in the past. This series of patches lets us continue to use the tried and true paths, as well as setting the stage for a migration to EFI for the next major supported branch of FreeBSD (12.x, not due for a release for about a year or so). FreeBSD 11 support needs to continue past FreeBSD 12's release. Finally, as Emmanuel has said, there's still some rough edges to FreeBSD/arm's EFI support that need to be worked through in parallel before people will switch to the new way.
Thanks a lot to both of you for the detailed description. That indeed makes a lot of sense altogether.
Alex