gcc has internal error at ljmp

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iammisc
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gcc has internal error at ljmp

Post by iammisc »

In gas i try to do

ljmp $0x20,$(%eax)

but gas says internal compiler error. please report this bug.

that is all fine and dandy(the bug reporting thing) but how do i compile my kernel.
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Combuster
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Post by Combuster »

you are trying to assemble something that an intel processor can't do:

according to intel's big book of patterns you can only:
JMP FAR immediate:immediate
or
JMP FAR [far_pointer_in_memory]

you can not:
JMP FAR immediate:register
and especially not
JMP FAR 0x20:[DS:EAX]
Which throughly messes up GAS into asking you to go tell the developers...
"Certainly avoid yourself. He is a newbie and might not realize it. You'll hate his code deeply a few years down the road." - Sortie
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iammisc
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Post by iammisc »

um. i never knew that.

It also says i can't do inter-privelege-level jmps so how do i call a callback in userspace? For my ipc i want to call a callback function for each message received, however i need to know how to do this.

thanks.
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