Any ideas as to where can I get more details on the various OSes boot
sequence on the PDP11?
Should have details like what disk block goes to which core address, how
to find/load/jump to the kernel..etc.
Paul Koning wrote:
>>>>>>"wai-sun" == wai-sun chia <squidster_at_techie.com> writes:
>
>
> wai-sun> Hello list, I'm trying to figure out the boot sequence on
> wai-sun> both the RK05 and RL02 drive from a PDP. Here's how I
> wai-sun> understand it so far:
>
> wai-sun> 1. Get the bootstrap in core either via the FP or PTR.
> wai-sun> 2. Execute bootstrap and pull in the absolute loader from
> wai-sun> 1st. sector of 512 bytes or 256 words; i.e. copy 1st. sector
> wai-sun> of drive to core starting from 0 3. Execute absolute loader
> wai-sun> by a JMP 0. 4. ??? What happens next ???
>
> Typically, what happens next is that more initialization code is read
> in from the disk. How much and where it comes from depends on the OS.
>
> For example, in RT11 the bootstrap is 2 blocks long (block 2 is the
> rest). It reads the directory to find the kernel and loads that, then
> jumps to it. (Give or take some handwaving; Megan can improve on this
> in her sleep...)
>
> In RSTS, the bootstrap contains a list of disk blocks where the
> init.sys program lives; first it moves itself up into high memory and
> then it reads init.sys using that table, and jumps to the entry
> point. Init.sys finds all the hardware, does all sorts of setup, and
> finally loads the OS.
>
> IAS and RSX-11D have a saved memory image; the boot loader loads that
> and then fakes a powerfail interrupt. The power restore routines then
> reinitialize ths OS and drivers, and you're up.
>
> Other PDP11 operating systems -- no idea, but changes are it's a
> variation on one of these themes.
>
> paul
>
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Received on Thu Jul 01 2004 - 11:37:32 BST