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In Setup.S,
lmsw ax (ax=1 ), so we cut into protected
mode..
Now comes my question ==>
(1). Just after running LMSW, I guess the CPU accessses memory
as 8086 (where CS*16+IP.)
Only After we reload
cs by far jmp, then CPU ACTUALLY accesses memoey via GDT.
And then CPU really work on
32-bit Code ..
Is my guess right
?
(2). Friends on net tell me zImage is put on 0x10000 (ie.
64k absoloute address),
But the source reload the CS
by =>
db
0x66,0xea ! prefix + jmpi-opcode
code32: dd 0x1000 <--------------------- This line is strange. it should be 0x10000 not 0x1000, it should means offset not a segment ???
Is anything wrong with my idea
??
dw KERNEL_CS ( mixed 16-32
bits, by so it can jump to bzImage, too .. I guess)
-------------------------------------------------------------------------------------
KERNEL_CS is a index to GDT , which means BASE address is
0x0000
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