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| author | Jeffrey Armstrong <jeff@approximatrix.com> | 2024-11-13 13:51:48 -0500 |
|---|---|---|
| committer | Jeffrey Armstrong <jeff@approximatrix.com> | 2024-11-13 13:51:48 -0500 |
| commit | 41d6a33d31d348563a9c97b7cf25752e8e64f599 (patch) | |
| tree | 9a111a5e467d235804b9232c5e9f187b8af5a638 /asm | |
| parent | f1d017401b0efef229a45d1b4ffeca95a287594b (diff) | |
| download | GWFetch-41d6a33d31d348563a9c97b7cf25752e8e64f599.tar.gz GWFetch-41d6a33d31d348563a9c97b7cf25752e8e64f599.zip | |
Added bus width detection that appears to work on an 8088.
Diffstat (limited to 'asm')
| -rw-r--r-- | asm/386q.asm | 61 |
1 files changed, 52 insertions, 9 deletions
diff --git a/asm/386q.asm b/asm/386q.asm index 4496d66..bf58033 100644 --- a/asm/386q.asm +++ b/asm/386q.asm @@ -1,3 +1,14 @@ + ; Results:
+ ; 0 - 8088
+ ; 1 - 8086
+ ; 2 - V20
+ ; 3 - V30
+ ; 4 - 80188
+ ; 5 - 80186
+ ; 6 - 80286
+ ; 7 - 80386+
+
+
push bp
mov bp, sp
@@ -13,8 +24,8 @@ cmp ax, 0xf000 ;0f000h
je lessthantwoeightsix
- ; marked as 286 (2)
- mov dl, 2
+ ; marked as 286 (6)
+ mov dl, 6
mov ax, 0x7000 ;7000h
push ax
@@ -25,24 +36,25 @@ and ax, 0x7000 ;7000h
jz alldone
- ; mark as 386 (3)
+ ; mark as 386 (7)
inc dl
jmp alldone
lessthantwoeightsix:
- mov dl, 1
+ ; Mark as 80188 (4)
+ mov dl, 4
mov al, 0xff ;0ffh
mov cl, 0x21 ;21h
shr al, cl
; if the shift leaves zero, it's a 8088 class cpu, else 80186/88
- jnz alldone
+ jnz buswidth
- ; Lets see if we have a V20/V30 (V)
- mov dl, 0x56 ;056h
+ ; Lets see if we have a V20/V30 (2)
+ mov dl, 2
sti
push si
@@ -55,11 +67,42 @@ lessthantwoeightsix: pop si
or cx, cx
- jz alldone
+ jz buswidth
- ; mark as a 8088/8086 (0)
+ ; mark as a 8088/8086 (1)
mov dl, 0
+buswidth:
+
+ ; we are destroying es now, must be restored later
+ push cs
+ pop es
+ std
+
+ ; The 99 _must_ be replaced with the true offset of qqend
+ mov di, 99 ; OFFSET qqend ;99
+
+ ;set up al and cx: 0xfb is the 'sti' instruction
+ mov al, 0xfb
+ mov cx, 3
+
+ ; disable interrupts
+ cli
+ rep stosb
+
+ cld
+ nop
+ nop
+ nop
+ inc dx
+ nop
+qqend:
+ sti
+
+ ; ES must be restored
+ push ds
+ pop es
+
alldone:
; store in ax
xor dh, dh
|