Messages in this thread | | | Date | Sat, 16 Oct 1999 13:06:44 -0400 (EDT) | From | "Richard B. Johnson" <> | Subject | Re: bootsect.S changes |
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On Sat, 16 Oct 1999, Alan Modra wrote:
> On Fri, 15 Oct 1999, Richard B. Johnson wrote: > > > [re: gas 16-bit mode] > > I think this is still a 'work in progress'. I hope that somebody adds > > Please let me know of any problems in the latest 2.9.5 assembler. It's > fairly good now, I think. > > > a directive to gas that tells it to assemble 16-bit code so the source > > code doesn't have to be wrong to get it to make 16-bit code. The > > .code16 # 16-bit mode > .code16gcc # bastardised 16-bit mode that uses 32-bit call, ret so > # gcc gets the expected stack frame - also adds addr > # prefix automatically when presented with 32-bit > # base/index The idea is to use gcc to generate code that > # runs in 16-bit/real mode - *** on x86, x >= 3 *** > .code32 # 32-bit mode (default) > > >[snip] > > word operations. Therefore, an assembler needs to 'know' when to > > not use 0x66. In other words it needs to know the current operation > > mode of the processor. > > Yup. gas tracks .code16/32 and addr prefix given on same line as insn. >
ON EVERY LINE??? Gawd, what a mess. No wonder it doesn't seem to work. It should stay in whatever mode until explicitly changed to some other mode.
Cheers, Dick Johnson **** FILE SYSTEM WAS MODIFIED **** Penguin : Linux version 2.3.13 on an i686 machine (400.59 BogoMips). Warning : It's hard to remain at the trailing edge of technology.
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