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About mov instruction and gs register

I am writting a program for target board which have a 486 cpu, 512K ram(0x0 to 0x7ffff), 512k flash (0x80000 to 0xFFFFF).My program will be burned into flash. My program is to initialize the GDT, IDT, TSS, move them to memory. Now I can enter protected model and mov GDT, IDT correctly.But when I am about to mov TSS, some exception came out, and the CPU reset automaticly. The code casue the problem is like this: mov cx, gdt_idx mov gs, cx when cpu run to the instuction 'mov gs, cx', CPU will reset. i can assure the value in cx is correctly.

can any one give me some tips about how can this be happend?

thanks.

Reply to
leilei
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If you get no answers on this group try comp.lang.asm.x86. There is a lot x86 activity there.

Hul

leilei wrote:

Reply to
dbr

This seems to have nothing to do with TSS, yet. The CPU is not happy with the selector attempted to load GS with.

Please check that the number in CX is a valid GDT selector within the table range.

It also seems that there is no handler available for the exception generated by the segment loading.

--

Tauno Voipio
tauno voipio (at) iki fi
Reply to
Tauno Voipio

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