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Fixed paging test and newAddr()

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This commit is contained in:
Jeff Parsons 2015-05-09 09:34:18 -07:00 • committed by jeffpar
commit 65ca078b55
3 changed files with 19 additions and 15 deletions
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28
tests/pc/80386/tests.nasm
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@ -39,7 +39,7 @@
bits 16
PAGING equ 0
PAGING equ 1
;
; If we built our data structures in RAM, we might use the first page of RAM (0x0000-0x0fff) like so:
@ -199,18 +199,21 @@ initGDT:
%endif
;
; Now we want to build a page directory and a page table, but we need two pages of
; 4K-aligned physical memory. We can use hard-coded addresses in we're running in ROM,
; otherwise we ask DOS for some memory.
; 4K-aligned physical memory. We can use a hard-coded address (segment 0x100, corresponding
; to physical address 0x1000) if we're running in ROM; otherwise, we ask DOS for some memory.
;
cmp ax,CSEG_REAL
mov edi,0x1000 ; default to the 2nd physical page in low memory
mov ax,0x100 ; default to the 2nd physical page in low memory
je initPages
mov bx,0x1000 ; 4K paragraphs == 64K bytes
mov ah,DOS_SETBLOCK ; resize the current block so we can allocate a new block
int INT_DOS
jnc allocPages
exitErrDOSMem:
mov dx,errDOSMem
exitErrDOS:
mov ah,DOS_STD_CON_STRING_OUTPUT
int INT_DOS
@ -231,20 +234,21 @@ allocPages:
;
; AX == segment of 64K memory block
;
initPages:
movzx eax,ax
shl eax,4
add eax,0xfff
and eax,~0xfff
mov edi,eax ; EDI == first physical 4K-aligned page within the 64K
initPages:
mov esi,edi ; ESI == saved copy of EDI
mov esi,eax ; ESI == first physical 4K-aligned page within the given segment
shr eax,4
mov es,ax
xor edi,edi
;
; Build a page directory at EDI with only 1 valid PDE (the first one)
; Build a page directory at ES:EDI with only 1 valid PDE (the first one)
;
cld
cli ; make sure interrupts are still off (in case any DOS calls turned them back on)
mov eax,edi
mov eax,esi
add eax,0x1000 ; EAX == page frame address (of the next page)
or eax,PTE_USER | PTE_READWRITE | PTE_PRESENT
stosd
@ -284,7 +288,7 @@ toProt32:
;
; Test moving a segment register to a 32-bit memory location
;
test1: mov edx,[0x0000] ; save the DWORD at 0x0000:0x0000 in EDX
test1: mov edx,[0x0000] ; save the DWORD at 0x0000:0x0000 in EDX
or eax,-1
mov [0x0000],eax
mov [0x0000],ds
@ -295,7 +299,7 @@ test1: mov edx,[0x0000] ; save the DWORD at 0x0000:0x0000 in EDX
xor eax,0xffff0000
cmp eax,[0x0000]
jne error
mov [0x0000],edx ; restore the DWORD at 0x0000:0x0000 from EDX
mov [0x0000],edx ; restore the DWORD at 0x0000:0x0000 from EDX
jmp test2
;
; Test moving a byte to a 32-bit register with sign-extension