Intel 80287, 80286 manual Intel·

intel· 80286 SYSTEM INITIALIZATION

. Iarl endp

Copy Ihe T55 and LDT for Ihe I •• k polnled 01 by C5:BX. If Ihe la.k ha. an LDT II will 01.0 be copied down.

BX and BP are Iran . parenl .

bad_I •• :

h I I

copy_lo.k.

mov mov mov mov

I. I

mov

I a r

1n z

mov and cmp

1n z

I. I

cmp

1b

proc

• I , g d I_a I I a •

d. , • I

• I , c. : I b x I • I •• _a Ila .

I! !!I , !!Ii

e x I !I 1

• I , c. : I b x I • I • ' _ ' e I

d x I !!I 1

ba d_ 15.

d I , d h

dh,nol DPL dh,T55_ACCE55

b a d_ I ••

C X I !!I 1

cx , T 5 5_5 I Z E - 1 b a d_ 15.

Hall here If TSS 15 Invalid

Gel addre5 . ablllly 10 GDT

Gel . eleclor for TSS alia . Polnl ES al alia . dala .egmenl Gel lenglh of TSS alia .

Gel T55 5eleclor

Gel alia . acee5' rlghl . Jump If Invalid reference

Save TSS de5crlplor acce5' byle Ignore privilege

See If T5S Jump If nol

Gel lenglh of EPROM ba.ed TSS Verify II 15 of proper . Ize Jump if II 15 nol big enough

Selup for moving Ihe EPROM-ba5ed T55 10 RAM D5 polnl . al GDT

mov	[ • I I . a c c e •• , DS_A CC E 5 5
mov	d 5 I 5 1
call	cop y_w I I h_ f i I I

Make TSS Inlo dala 5egmenl Polnl DS al EPROM T5S

Copy DS 5egmenl 10 ES wllh zero fill CX ha5 copy counl, AX-CX fill counl

5el Ihe GDT T55 Ilmil and ba5e addre55 10 Ihe RAM values.

mov	ax,gdl _ allas
mov	d 5. 1	a x
mov	e 5 I	a x
mov	d i , C 5: [b x I • 15 5_S e I
mov	!I i ,e 5: [ b x] . t 5 :i_a 1 i c s
movsIII
mOV!!I1II
lod.w
mov	a h , d I

5 t 0 !!I \II

movsw

Reslore GDT addres51ng

Gel TSS 5eleclor

G'et RAM alia . 5eleclor Copy llmi I

Copylow 16 bi15 of addre55 Gel high 8 bil5 of address Mark a5 TSS de5crlplor

Fill In high addre5s and access byle5 Copy reserved word

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