ivar@acc.uu.no (Ivar Hosteng) (09/03/89)
I am experimenting with small programs in assembly and is trying to get them
as small as possible. Therefore I need the numbers for the system calls (the
value to put in the eax register before I call the kernel). If anybody knows
how to make a far call in masm I would be glad to be told how to do this.
I have tried to put a segment at 0x7 and make a far call to a label in that
segment but masm refused to assemble it. The solution I have used is to
hardcode the far call with db statements using this macro:
system MACRO ; macro to trap into kernel in xenix 386
push 0 ; dummy return address
db 09ah ; opcode for far call
dd 0 ; offset
dw 7 ; segment
sub esp,4 ; clean up the stack
ENDM
This looks awfully dirty so I wonder if it is a cleaner way to do this without
linking in the c libraries.
And while I am at it, why isn't SCO giving the source to the startup code
away with the development kit? You get it with Microsoft's C compiler under
MSDOS and OS/2.
--
Ivar E. Hosteng, Advanced Computer Consultans, Oslo, Norway
Internet: ivar@acc.uu.no
UUCP: ...!{uunet,mcvax,ifi}!acc.uu.no!ivar
'Just what do you think you are doing Dave?' -HAL9000