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authorhpa <hpa>2002-04-28 05:40:11 +0000
committerhpa <hpa>2002-04-28 05:40:11 +0000
commitbdb0fcf1acccec785084bfe0b3802d4674638b64 (patch)
treebfe06e9b601affd91f3e028a3e274dc05a668c13 /bcopy32.inc
parentc0cd85e0e93e2390f3f33169c78e4ed0033e5ceb (diff)
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Factor out CPU initialization and some common configuration intosyslinux-1.73-pre6
separate files; fix bcopy bugs.
Diffstat (limited to 'bcopy32.inc')
-rw-r--r--bcopy32.inc39
1 files changed, 21 insertions, 18 deletions
diff --git a/bcopy32.inc b/bcopy32.inc
index af322f91..ed14aee8 100644
--- a/bcopy32.inc
+++ b/bcopy32.inc
@@ -77,7 +77,7 @@ bcopy: push eax
mov eax,cr0
or al,1
mov cr0,eax ; Enter protected mode
- jmp 08h:.in_pm
+.adj3a: jmp 08h:.in_pm
.in_pm: mov ax,10h ; Data segment selector
mov es,ax
@@ -91,23 +91,20 @@ bcopy: push eax
mov al,cl ; Save low bits
shr ecx,2 ; Convert to dwords
a32 rep movsd ; Do our business
+ ; At this point ecx == 0
- test al,2
- jz .noword
- a32 movsw
-.noword:
- test al,1
- jz .nobyte
- a32 movsb
-.nobyte:
-
- mov es,ax ; Set to "real-mode-like"
+ mov cl,al ; Copy any fractional dword
+ and cl,3
+ a32 rep movsb
+
+ mov al,18h ; "Real-mode-like" data segment
+ mov es,ax
mov ds,ax
-
+
mov eax,cr0
and al,~1
mov cr0,eax ; Disable protected mode
-.adj3: jmp 0:.in_rm
+.adj3b: jmp 0:.in_rm
.in_rm: ; Back in real mode
lss sp,[cs:SavedSSSP]
@@ -144,7 +141,6 @@ bcopy: push eax
A20List dw a20_dunno, a20_none, a20_bios, a20_kbc, a20_fast
A20DList dw a20d_dunno, a20d_none, a20d_bios, a20d_kbc, a20d_fast
a20_adjust_cnt equ ($-A20List)/2
-A20Type dw A20_DUNNO ; A20 type unknown
slow_out: out dx, al ; Fall through
@@ -160,7 +156,9 @@ try_enable_a20:
;
; Flush the caches
;
-; call try_wbinvd
+%if DO_WBINVD
+ call try_wbinvd
+%endif
;
; If the A20 type is known, jump straight to type
@@ -287,7 +285,9 @@ disable_a20:
;
; Flush the caches
;
-; call try_wbinvd
+%if DO_WBINVD
+ call try_wbinvd
+%endif
mov bp,[cs:A20Type]
add bp,bp ; Convert to word offset
@@ -359,11 +359,13 @@ empty_8042:
.done: ret
;
-; WBINVD instruction; gets auto-eliminated on 386 CPUs
+; Execute a WBINVD instruction if possible on this CPU
;
+%if DO_WBINVD
try_wbinvd:
wbinvd
ret
+%endif
;
; bcopy_over_self:
@@ -388,7 +390,8 @@ try_wbinvd:
align 2
adjlist dw bcopy_gdt.adj1 - ADJUST
dw bcopy.adj2 + 5 - ADJUST
- dw bcopy.adj3 + 1 - ADJUST
+ dw bcopy.adj3a + 1 - ADJUST
+ dw bcopy.adj3b + 1 - ADJUST
dw try_enable_a20.adj4 + 3 - ADJUST
dw disable_a20.adj5 + 3 - ADJUST
adjlist_cnt equ ($-adjlist)/2