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Re: [Qemu-devel] [RFC PATCH 1/2] serial console, output


From: Paolo Bonzini
Subject: Re: [Qemu-devel] [RFC PATCH 1/2] serial console, output
Date: Mon, 4 Jul 2016 18:03:30 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1


On 04/07/2016 18:00, Kevin O'Connor wrote:
> So, if I read the sgabios code correctly, it allocates a buffer of:
> 
> struct { u8 x, y; char c; } logbuf[256];
> int logbuf_offset;
> 
> Every character sent on the serial port is appended to "logbuf" in
> order, wrapping if necessary: logbuf[logbuf_offset++ % 256] = x, y, c.
> On a read, it scans backwards from logbuf_offset to find the last
> update to that cell.
> 
> Interestingly, it doesn't store the attribute with the character -
> it's int1008 handler just returns the last attribute used anywhere on
> the screen.
> 
> The code is only used if it is the sole vga code (as opposed to being
> used in addition to an existing vgabios).
> 
> Does anyone know where one can find the original svn commit history
> for sgabios?  Seems the original google code repo is no longer
> present.

There was no history as far as I remember, mostly a code drop.

Paolo



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