Date: Fri, 05 Nov 2004 21:34:26 +0100 From: Willem Jan Withagen <wjw@withagen.nl> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-arch@freebsd.org Subject: Re: Booting questions .... Message-ID: <418BE3D2.2030205@withagen.nl> In-Reply-To: <200411051400.34684.jhb@FreeBSD.org> References: <418AB176.9030604@withagen.nl> <200411041835.46465.jhb@FreeBSD.org> <418AC4B3.9020305@withagen.nl> <200411051400.34684.jhb@FreeBSD.org>
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John Baldwin wrote: [about the loader having flat addressspace....] >>But is it unsegmented? (perhaps I have a wrong idea of a flat address >>space) > > > Yes, it is unsegmented. You can translate physical addresses to virtual > addresses using PTOV() and vice versa using VTOP(). I've run accross these calls, just need to figure out how to work them. >>What I mean with this is that I can iterate from 0xa000 to 0xffffffff with >>a "char *p" and do test_bytes( 0xa000, 0xffffffff, 0xff). (assuming this >>all has memory) > Yes. Would be nice.... >>Next is then which ranges are valid to test, and then things really start >>to get complicated and arch dependant. Which is why I ended up in machdep.c >>right after the setting up of the memory ranges. > > Heh, the above memory mapping is also i386 specific. Alpha only has a small > bit of memory mapped in the loader, same with sparc64, etc. Ehhhh, again more reasons to put this in the kernel, or something that closely resembles a kernel. --WjW
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