Messages in this thread | | | Subject | Re: [PATCH v11 3/6] arm64: dts: allwinner: Add Allwinner H616 .dtsi file | From | Samuel Holland <> | Date | Thu, 7 Jul 2022 01:30:32 -0500 |
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Hi Andre, Jernej,
On 7/6/22 8:16 AM, Andre Przywara wrote: > so after seemingly having finished writing this email, I realised that > this won't really help, as I think this diverts the discussion. And the > problem has been around for a while, and won't probably be solved easily > or quickly. I think we agree to disagree here, or we should admit that > there are different approaches ("bundled firmware" vs. "UEFI"), so in the > interest of not blocking the H616 series: > > Shall I just keep the firmware node? This would work both ways, whereas > dropping the node would impede the "bundled firmware" approach?
Let me try to sum up the relevant portion of my thoughts (and save the rest for elsewhere):
The only reason to add the reserved-memory node is to support externally-loaded DTBs. By adding the node, we are committing to support externally-loaded DTBs on this SoC.
Upgrading the kernel is not allowed to break boot. If we support externally-loaded DTBs, that rule extends to DTBs shipped with the kernel.
If we remove the reserved-memory node, the combination of old U-Boot + new externally-loaded DTB will stop booting (the kernel version is irrelevant). Therefore, if we add the node, we can never remove it, full stop.
I will (begrudgingly) accept that, as long as the node matches what TF-A actually generates today. That means, please: - Drop the label and update the node name - Reduce the size to 256 KiB, matching (BL31_LIMIT - BL31_BASE)
Regards, Samuel
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