On Sun, Feb 08, 2015 at 03:02:02PM +0000, Nuno Magalhães wrote: > Some guys at the WD forum suggested this could be a BIOS issue, which > kinda sucks as i'm not in the mood to get a new mobo. > I was under the impression linux doesn't really need the BIOS to > operate, but i'm not versed in the art of bootloading. Can anyone > point me to some reading material on this (just curious really)? Linux doesn't rely on the BIOS as much as, say, MS-DOS does, but it still needs it to boot. In the days of MS-DOS, the BIOS did a lot of work and the operating system communicated with the keyboard, video, disks etc by calling functions in the BIOS. This made the operating system simple, but was soon found to be too limiting. Linux accesses the hardware directly and, because it has access to the full capabilities of the processor, memory etc, it can, for example, write to disks which are larger than the BIOS can address. However, when you boot the computer, the BIOS is still invoked as the very first bit of executable code. It initialises the hardware and then reads the first sector of the first hard drive and executes that as native code. Typically, the instruction there is "Jump to this point on the hard disk (where the kernel is) and execute that code". The problem comes when that instruction to "jump to this point on the hard disk" points to a larger address than the BIOS can access. Various limitations have existed over the life of the BIOS standard: 528MB, 2.1GB, 3.2GB ... 137GB, 2TiB... If the BIOS is affected by one of these limits (which is usually caused by the variable(s) holding the disk capacity not being big enough), then the jump instruction makes no sense and the disk cannot be booted. The usual solution to this is to make a small /boot partition at the start of the disk (which CAN be jumped to) containing a boot-loader (such as grub) which can then switch into an addressing mode which CAN reach the kernel. > > > -- > To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org > Archive: [🔎] CADqA9uYKO__q6-zXecnO=zT8hLKWkDkV6NThyRfOPiaFXUNV9Q@mail.gmail.com">https://lists.debian.org/[🔎] CADqA9uYKO__q6-zXecnO=zT8hLKWkDkV6NThyRfOPiaFXUNV9Q@mail.gmail.com >
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