Re: [Qemu-devel] Question about qemu firmware configuration (fw_cfg) device

[Richard W.M. Jones]

On Sat, Jul 17, 2010 at 10:50:59AM +0100, Richard W.M. Jones wrote:
> I understand from the git logs that fw_cfg was added because the old
> way was to load kernel & initrd into RAM directly, but this didn't
> work because SeaBIOS would clear the RAM, clobbering kernel & initrd.
> Could we change to loading these directly into RAM, and instead
> provide some indication to SeaBIOS so it doesn't clobber the RAM?  I'm
> quite prepared to do the work, just wondering if there's something
> else I'm not getting about this.

Or thinking around the subject:

Change fw_cfg so that you send a command + a physical address, and
fw_cfg memcpy's the kernel / initrd / etc to that physical address.
Then linuxboot.bin doesn't have to do the manual copying.

Or just change linuxboot.bin so it does 32 bit inl instructions, which
might at least be a bit faster ...

Rich.

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