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Re: [Qemu-block] [Qemu-devel] [PATCH v2 07/11] ppc405_boards: Don't size
Re: [Qemu-block] [Qemu-devel] [PATCH v2 07/11] ppc405_boards: Don't size flash memory to match backing image
Fri, 08 Mar 2019 10:46:54 +0100
Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux)
David Gibson <address@hidden> writes:
> On Thu, Mar 07, 2019 at 08:01:35AM +0100, Markus Armbruster wrote:
>> Alex Bennée <address@hidden> writes:
>> > Markus Armbruster <address@hidden> writes:
>> >> Machine "ref405ep" maps its flash memory at address 2^32 - image size.
>> >> Image size is rounded up to the next multiple of 64KiB. Useless,
>> >> because pflash_cfi02_realize() fails with "failed to read the initial
>> >> flash content" unless the rounding is a no-op.
>> >> If the image size exceeds 0x80000 Bytes, we overlap first SRAM, then
>> >> other stuff. No idea how that would play out, but a useful outcomes
>> >> seem unlikely.
>> >> Map the flash memory at fixed address 0xFFF80000 with size 512KiB,
>> >> regardless of image size, to match the physical hardware.
>> >> Machine "taihu" maps its boot flash memory similarly. The code even
>> >> has a comment /* XXX: should check that size is 2MB */, followed by
>> >> disabled code to adjust the size to 2MiB regardless of image size.
>> >> Its code to map its application flash memory looks the same, except
>> >> there the XXX comment asks for 32MiB, and the code to adjust the size
>> >> isn't disabled. Note that pflash_cfi02_realize() fails with "failed
>> >> to read the initial flash content" for images smaller than 32MiB.
>> >> Map the boot flash memory at fixed address 0xFFE00000 with size 2MiB,
>> >> to match the physical hardware. Delete dead code from application
>> >> flash mapping, and simplify some.
>> > It seems to me the DEBUG_BOARD_INIT code is probably out of date cruft
>> > that could be excised all together. But that doesn't stop this being
>> > useful:
>> David, would you like me to excise DEBUG_BOARD_INIT?
> If you have the chance to look at it, that would be great.
Done in v4. Thanks!