diff options
Diffstat (limited to 'bcopy32.inc')
| -rw-r--r-- | bcopy32.inc | 39 |
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 |