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Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM
From: |
Finn Thain |
Subject: |
Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM |
Date: |
Fri, 25 Jun 2021 14:36:37 +1000 (AEST) |
On Thu, 24 Jun 2021, Mark Cave-Ayland wrote:
> Thanks for the link and the detailed testing information. I've been
> trying to understand why you had to set the MAC address in the ARC
> firmware so I had a bit of an experiment here.
>
> The reason that you need to do this is because of the NVRAM
> configuration in your command line, in particular -global
> ds1225y.size=8200. What this does is extend the NVRAM over the top of
> the dp8393x-prom area where QEMU places the NIC MAC address and checksum
> on startup, so the NVRAM captures the MAC address reads/writes instead.
> The net effect of this is that the empty NVRAM initially reads all zeros
> and why an initial setup is required to set the MAC address.
>
> This can be seen quite clearly in the "info mtree" output:
>
> 0000000080009000-000000008000b007 (prio 0, i/o): nvram
> 000000008000b000-000000008000bfff (prio 0, rom): dp8393x-prom
>
> However if you completely drop -global ds1225y.size=8200 from your
> command line then the NVRAM doesn't overrun into the dp8393x-prom area,
> and the ARC firmware picks up the MAC address from QEMU correctly:
>
> 0000000080009000-000000008000afff (prio 0, i/o): nvram
> 000000008000b000-000000008000bfff (prio 0, rom): dp8393x-prom
>
> I've also looked over the entire SONIC datasheet to see if the PROM
> format is documented, and according to that there is no non-volatile
> storage available on the chip itself.
Yes, that's my understanding also. The relevant National Semicondutor
Application Notes seem to include a separate PROM. And if you closely
examine the Linux macsonic.c driver, you'll see that the PowerBook 5x0
models get a random MAC address because no-one (outside of Apple) knows
where the real MAC address is stored.
> Testing shows that the checksum algorithm currently used for the dp8393x
> device generates the same result as that generated by the ARC firmware,
> which is known to be different than that used by the Q800 machine.
>
> From this I conclude that the PROM is provided by the board and not the
> chipset, and therefore each machine should construct its own PROM
> accordingly. I'll send a v2 patchset shortly with these changes which
> shall also include the proposed endian patch.
>
If you potentially have both a ds1225y NVRAM and a dp8393x PROM (for the
magnum machine) how do you avoid ending up with conflicting state? Would
the two storage devices have to be mutually exclusive?
- [PATCH 2/5] dp8393x: convert to trace-events, (continued)
- [PATCH 2/5] dp8393x: convert to trace-events, Mark Cave-Ayland, 2021/06/13
- [PATCH 4/5] dp8393x: don't force 32-bit register access, Mark Cave-Ayland, 2021/06/13
- [PATCH 5/5] dp8393x: fix CAM descriptor entry index, Mark Cave-Ayland, 2021/06/13
- [PATCH 3/5] dp8393x: fix PROM checksum and MAC address storage, Mark Cave-Ayland, 2021/06/13
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Philippe Mathieu-Daudé, 2021/06/14
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Mark Cave-Ayland, 2021/06/14
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Finn Thain, 2021/06/16
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Mark Cave-Ayland, 2021/06/16
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Finn Thain, 2021/06/18
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Mark Cave-Ayland, 2021/06/24
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM,
Finn Thain <=
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Mark Cave-Ayland, 2021/06/25
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Finn Thain, 2021/06/25
- Re: [PATCH 0/5] dp8393x: fixes for MacOS toolbox ROM, Mark Cave-Ayland, 2021/06/25