Date: Fri, 04 Jun 2004 09:27:24 +0800 From: David Xu <davidxu@freebsd.org> To: Nate Lawson <nate@root.org> Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/include/pc bios.h src/sys/i386/i386 bios.c Message-ID: <40BFCFFC.5040701@freebsd.org> In-Reply-To: <20040603160405.E45592@root.org> References: <20040603160405.E45592@root.org>
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Nate Lawson wrote:
> On Thu, 3 Jun 2004, Poul-Henning Kamp wrote:
>
>>phk 2004/06/03 15:36:24 PDT
>>
>> FreeBSD src repository
>>
>> Modified files:
>> sys/i386/include/pc bios.h
>> sys/i386/i386 bios.c
>> Log:
>> Add new bios_string() which will hunt for a string inside a given
>
> range
>
>> of the BIOS. This can be used for finding arbitrary magic in the
>
> BIOS
>
>> in order to recognize particular platforms.
>>
>> Revision Changes Path
>> 1.66 +15 -0 src/sys/i386/i386/bios.c
>> 1.15 +8 -0 src/sys/i386/include/pc/bios.h
>>
>>--- src/sys/i386/i386/bios.c:1.65 Sun May 30 10:57:42 2004
>>+++ src/sys/i386/i386/bios.c Thu Jun 3 15:36:24 2004
>>@@ -472,6 +472,21 @@
>> free(pte, M_TEMP); /* ... and free it */
>> }
>> return (i);
>>+}
>>+
>>+const u_char *
>>+bios_string(u_int from, u_int to, const u_char *string, int len)
>>+{
>>+ const char *t, *te;
>>+
>>+ if (len == 0)
>>+ len = strlen(string);
>>+ t = (const char *)(KERNBASE + from);
>>+ te = (const char *)(KERNBASE + to);
>>+ for (; t <= te; t++)
>>+ if (!memcmp(string, t, len))
>>+ return (t);
>>+ return (NULL);
>> }
>
>
> Many BIOS strings have alignment requirements. That might be useful to
> add. Is all of BIOS mapped into kernel memory or should this operate on
> physical addresses instead?
>
> -Nate
>
>
First 4M bytes are mapped at KERNBASE, right ?
I saw KERNLOAD is 4M bytes, and from page 1 to KERNLOAD are mapped
read-only, zero page is mapped R/W, all in locore.s.
David Xu
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