Date: Fri, 13 Nov 2020 16:45:25 -0800 From: Mark Millard <marklmi@yahoo.com> To: Robert Clausecker <fuz@fuz.su> Cc: freebsd-arm@freebsd.org Subject: Re: RPi4B: edk2-platforms updated because _DMA method for XHCI DMA issue insufficient for Linux; pftf/RPi4 v1.21 has the change Message-ID: <7769BE3C-33C6-4153-8E4B-A065E2281FD9@yahoo.com> In-Reply-To: <20201113234439.GA88059@fuz.su> References: <2D77549B-0A45-46DB-AD19-7E0B760DE857.ref@yahoo.com> <2D77549B-0A45-46DB-AD19-7E0B760DE857@yahoo.com> <20201113234439.GA88059@fuz.su>
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On 2020-Nov-13, at 15:44, Robert Clausecker <fuz at fuz.su> wrote: > Hi Mark, Hello Robert. > Does this change affect FreeBSD w/ UEFI in any way? Should I consider > updating the UEFI bootcode on my board? > . . . I do not know the FreeBSD implications of having the IORT table in the ACPI information for the RPi4B. Nor have I started experimenting to find out how things go with that. Having IORT limit the xHCI to 2 GiByte and the prior FreeBSD code's separate limit handling leaves me worried but I'm ignorant of the actual implications. I've been running the RPI4B with a more recent start4.elf (and such) since the corruption issue was fixed, but mostly booted via u-boot 2020.10 (from before the port was upgraded to 2020.10). The pftf/RPi4 v1.21 materials may be using something more recent than I have in place for start4.elf . It may be some time before I have user experience information to report. Other aspects of my FreeBSD context are dated and need updating as well. > On Fri, Nov 13, 2020 at 02:55:21PM -0800, Mark Millard via freebsd-arm = wrote: >>=20 >> Quoting = https://github.com/tianocore/edk2-platforms/commit/dac891da5cf326d2b4e9aa5= adab1d9320b2dd443 : >>=20 >> Add an IORT table that will limit XHCI DMA to 2 GB, by setting the >> DMA width to 31 bits. This is needed for Linux/arm64, which can >> only reliably deal with devices that are unable to perform DMA to >> the entire 32-bit address range if it can discover their existence >> early during boot, and this is before the ACPI interpreter is up >> and running (which rules out calling the _DMA method of the XHC0 >> object) >>=20 >> End Quote >>=20 >> https://github.com/pftf/RPi4/releases/tag/v1.21 includes this change. >> (It also updates the RPI4B firmware to quit using the broken = start4.elf >> that corrupted Device Tree information.) >>=20 =3D=3D=3D Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)
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