Re: paper tape bootstraps


<ArarghMail108NOSPAM@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:jmsi671t2tu7ol09t3v7advvh8t5bfefbg@xxxxxxxxxx

CS & IP, which are usually 0000 & 7C00. If not, some MBRs or boot
sectors may not work correctly.

I allow for that by doing a jmp far 0000:<next loc> which sets CS to
what I expect, assuming that I was actually loaded at 0:7C00. :-)

As long as you don't use the CS: override, it really doesn't
matter what the CS:IP contents are (within reason*).

If you don't use anything like:

push cs
pop ds

mov ax,cs
mov dx,ax

mov ax,cs:[some_var]

then you don't have to do the 'jmp far' to set CS.

But I am sure you already knew this. :-)

Thanks,
Ben

*As long as IP <= 0xFE00. However, you can't get a physical
pointer to 0x07C00 with IP > 0x7C00 anyway. :-)

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