On Wed, Oct 25, 2023 at 04:18:20PM +0200, Mark Kettenis wrote:
Date: Tue, 24 Oct 2023 18:34:05 -0400 From: Tom Rini trini@konsulko.com
On Mon, Oct 23, 2023 at 05:31:19PM +0200, Mark Kettenis wrote:
From: Simon Glass sjg@chromium.org Date: Mon, 23 Oct 2023 00:04:14 -0700
Hi Caleb,
On Sat, 21 Oct 2023 at 01:43, Caleb Connolly caleb.connolly@linaro.org wrote:
Hi Simon,
On 21/10/2023 01:45, Simon Glass wrote:
U-Boot typically sets up its malloc() pool near the top of memory. On ARM64 systems this can result in an SMBIOS table above 4GB which is not supported by SMBIOSv2.
[snip]
There is absolutely no guarantee that arm64 machines have memory below 4GB. Examples of SoCs that have no memory below 4GB are AMD's Opteron A1100 SoC and all the recent Apple SoCs.
So one thing to resolve here is where does that requirement about the SMBIOS table needing to be below 4GB come from (standards wise), and in turn is that obeyed by consumers like say Linux or OpenBSD? Answering my own question, maybe in part, https://www.dmtf.org/standards/smbios reads to me like there's a v3 and maybe we should be doing what we need to support / identify as that, if it doesn't have that restriction?
Right. U-Boot implements SMBIOS 2.x which is pretty much obsolete and uses 32-bit addresses. SMBIOS 3.x allows for 64-bit addresses. So to fix this U-Boot needs support for SMBIOS 3.x.
OK, thanks. And for clarity / repeating my confusion, at least right now we also set the major/minor in the struct to 3.0.
Personally I don't see why we'd need SMBIOS support on non-x86 platforms, which is why implementing this isn't a high priority for me. I simply disabled SMBIOS support for M1 for now.
This I think in turn (based on Heinrich's emails in v2 of this patch) EFI_LOADER wants to pass SMBIOS (probably 3) information along so that human user facing tools can see the kind of info that table provides.