Date: Thu, 12 May 2005 21:58:10 +0200 From: alexander <arundel@h3c.de> To: freebsd-hackers@FreeBSD.org Subject: Accessing BIOS memory range Message-ID: <20050512195810.GA61334@skatecity> In-Reply-To: <6.2.1.2.2.20050512180519.03403540@202.179.0.80> References: <6.2.1.2.2.20050512180519.03403540@202.179.0.80>
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Hi there. I'm writing a little app in 32 bit x86 (386 minumum) assembly, where I need to access some memory in the BIOS range. The real address is 40h:6Ch (virtual = ((0x40<<4) | 0x6C)). Gaining access to the I/O ports isn't a big problem (open fd for /dev/io), but I don't know how to gain access to memory that isn't part of my user address space. Any hints? I heard that maybe /dev/mem or /dev/kmem might let me gain access to the BIOS memory, but 'man' tells me that the range is limited to the following range: 0x000a0000 to 0x00100000/0xf0000000 ?? Is it even possible to gain access to that memory area (of course as 'su'). I'd be really if somebody could give me a hint where I have to look (mem, kmem, io ???). Thx in advance.
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