Date: Sun, 27 Sep 2020 13:44:29 -0700 From: Mark Millard <marklmi@yahoo.com> To: Brandon Bergren <bdragon@FreeBSD.org> Cc: FreeBSD PowerPC ML <freebsd-ppc@freebsd.org> Subject: Re: head -r365932 on PowerMac G5 (2 dual-core sockets): Crashes before login prompt if powerd is enabled in /etc/rc.conf Message-ID: <7DC3081D-8B19-476A-990F-4DFD7003672C@yahoo.com> In-Reply-To: <88052e3f-4b79-45ca-8ebb-9fc19cbc558b@www.fastmail.com> References: <52783D16-5DCA-45BC-9238-2518326454A1@yahoo.com> <6E99EE39-D2B8-415A-A5BF-823C0F0C22D6@yahoo.com> <cd9d2b72-219f-4550-a437-4ac3aa1da66d@www.fastmail.com> <AF27169A-00FC-4984-83C2-307EA885D7A1@yahoo.com> <11fe573a-24c3-47be-95ed-c601ec54f168@www.fastmail.com> <E23CF7F6-B69C-44C7-B356-4AB65E011268@yahoo.com> <B4D16405-1B0C-4500-866F-75F32FED235A@yahoo.com> <92f57afb-33cb-4d38-be17-4b8c81cb9c89@www.fastmail.com> <D6DC1C60-E50D-4A12-9F3B-6CEBA6A76748@yahoo.com> <6a0ade9d-26f2-4448-b066-0b06ed3ba5ef@www.fastmail.com> <9D4314E7-92C9-4BDD-B023-8C9BC3DCCAB0@yahoo.com> <E1EEDF91-42B1-4319-9513-7DE6FDE6E5F3@yahoo.com> <F1808C34-3C1A-44DC-BB23-2F0959AC64F5@yahoo.com> <db3de197-eb27-40ef-89ac-433b7fa72fe4@www.fastmail.com> <5E79BB07-D54B-4A8E-B592-F480211D0B92@yahoo.com> <88052e3f-4b79-45ca-8ebb-9fc19cbc558b@www.fastmail.com>
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On 2020-Sep-23, at 09:09, Brandon Bergren <bdragon@FreeBSD.org> wrote: > On Wed, Sep 23, 2020, at 3:58 AM, Mark Millard wrote: >> On 2020-Sep-23, at 00:04, Brandon Bergren <bdragon at FreeBSD.org> wrote: >> >>> . . . >>> >>> Are you making sure to use the "dev /memory@0 100000 1000 do-unmap" trick on 4.8.7f1 devices? >> >> I know nothing about that and have never had to do such a thing >> historically. I've never had to identify "4.8.7f1 devices". > > There is a bug in some versions of the PowerMac BootROM where a memory page at 0x100000 would remain mapped without being properly listed in the mmu properties (likely due to the way Open Firmware was initialized) that breaks bootloaders that touch that page. > > It is known to be a thing on at least 4.8.7f1 BootROM, but may also affect other versions. You can see the BootROM version on the OpenFirmware screen when the machine turns on. > > On affected devices, the bug can be permanently repaired using nvedit to execute the workaround automatically, or it can be typed in by hand every time. > > This is described on https://wiki.freebsd.org/powerpc In case it is related: in ofwfdt_fixups my environment uses: offset = fdt_path_offset(fdtp, "/rtas"); if (offset > 0) { . . . } else { #if 0 // Without the /memory0/available information the example // MPC750 iMac G3 PowerMac4,1 crashes shortly after booting // --from trashed memory contents from use of RAM that was // not excluded when available was being deleted. // // My guess is that openfirmware may also report to // avoid address ranges for which other things in the // environment are the cause, not just openfirmware's // internal memory use. // // So do not do the following . . . /* * Remove /memory/available properties, which reflect long-gone * OF state. Note that this doesn't work if we need RTAS still, * since that's part of the firmware. */ offset = fdt_path_offset(fdtp, "/memory@0"); if (offset<=0) offset= fdt_path_offset(fdtp, "/memory@0,0"); // G5's if (offset > 0) fdt_delprop(fdtp, offset, "available"); #endif } The // G5's line is also mine. === Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)home | help
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