Date: Fri, 14 Aug 1998 08:46:21 -0400 From: Randall Hopper <rhh@ct.picker.com> To: Gregory Hosler <greg@camelot.eno.ericsson.se>, Roger Hardiman <roger@cs.strath.ac.uk> Cc: multimedia@FreeBSD.ORG Subject: Re: Putting the bt848 driver into the GENERIC kernel Message-ID: <19980814084621.A6084@ct.picker.com> In-Reply-To: <XFMail.980814084226.greg@camelot.eno.ericsson.se>; from Gregory Hosler on Fri, Aug 14, 1998 at 08:42:26AM %2B0730 References: <35D2C9DC.47D0@cs.strath.ac.uk> <XFMail.980814084226.greg@camelot.eno.ericsson.se>
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Gregory Hosler: |On 13-Aug-98 Roger Hardiman wrote: |>Soren suggested a BOOTKERNEL and BIGKERNEL. | |why not just compile the driver as a loadable module ? | |just curious, Roger recounted through that in a recent thread (attached). The issue is the vm_contig_alloc call the driver uses to alloc the DMA phys memory doesn't work after the system has booted. It doesn't have the smarts to bump/swap/rearrange phys page mappings to get suffic contig phys mem. Know any VM hackers that could take a crack at it? Having a bt848 driver LKM would be really cool. :-) As would not having the driver alloc the uffer on probe/attach, but rather on open where it makes the most sense. Randall Date: Thu, 13 Aug 1998 17:16:48 +0100 From: Roger Hardiman <roger@cs.strath.ac.uk> Organization: University of Strathclyde Subject: Re: FXTV and DGA Scott > > This may be a dumb suggestion (I don't use fxtv so I have no idea if > this will work or not), but couldn't the driver be made into an LKM? Funny you should mention it, but Amancio, Randall and later myself talked about this around 8 months ago. The problem was basically this. You need to allocate configuous memory for the frame buffer. At boot time, this is easy. Memory is empty and you can allocate a 864k block of memory with no gaps in it. However, I was told that by the time the system has booted, and the LKM executed, there is quite possible you cannot get a contiguous block of memory as the memory is fragmented. Basically, you need a memeory manager that can shift memory blocks around making a large space. I was told the current memory management code cannot do this. But if we could do it, then the LKM would be great. Bye Roger Roger Hardiman Strathclyde Uni Telepresence Group To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message
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