Changeset 96 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers

Timestamp:

Jan 28, 2011, 4:29:42 PM (14 years ago)

Author:

Tomi Tilli

google:author:

aitotat

Message:

Changes to XTIDE Universal BIOS:

• Cleaned boot loader code some more.

Location:

trunk/XTIDE_Universal_BIOS/Src/Handlers

Files:

• Int19h.asm (deleted)
• Int19hMenu.asm (modified) (4 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int19hMenu.asm

@@ -22 +22 @@
 
     ; Install new INT 19h handler now that BOOTVARS has been initialized
-    mov     WORD [INTV_BOOTSTRAP*4], Int19hMenu_Display
+    mov     WORD [INTV_BOOTSTRAP*4], DisplayBootMenu
     mov     WORD [INTV_BOOTSTRAP*4+2], cs
-    ; Fall to Int19hMenu_Display
+    ; Fall to DisplayBootMenu
 
 ;--------------------------------------------------------------------
-; Displays Boot Menu so user can select drive to boot from.
-;
-; Int19hMenu_Display
+; DisplayBootMenu
 ;   Parameters:
 ;       Nothing
@@ -36 +34 @@
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
-Int19hMenu_Display:
-    sti                                 ; Enable interrupts
+DisplayBootMenu:
     call    BootVars_SwitchToBootMenuStack
     call    RamVars_GetSegmentToDS
-    ; Fall to Int19hMenu_ProcessMenuSelectionsUntilBootable
+    ; Fall to .ProcessMenuSelectionsUntilBootable
 
 ;--------------------------------------------------------------------
-; Processes user menu selections until bootable drive is selected.
-;
-; Int19hMenu_ProcessMenuSelectionsUntilBootable
+; .ProcessMenuSelectionsUntilBootable
 ;   Parameters:
 ;       DS:     RAMVARS segment
@@ -52 +47 @@
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
-Int19hMenu_ProcessMenuSelectionsUntilBootable:
+.ProcessMenuSelectionsUntilBootable:
     call    BootMenu_DisplayAndReturnSelection
     call    DriveXlate_ToOrBack         ; Translate drive number
-    call    Int19h_TryToLoadBootSectorFromDL
-    jnc     SHORT Int19hMenu_ProcessMenuSelectionsUntilBootable ; Boot failure, show menu again
+    call    BootSector_TryToLoadFromDriveDL
+    jnc     SHORT .ProcessMenuSelectionsUntilBootable   ; Boot failure, show menu again
     call    BootVars_SwitchBackToPostStack
-    jmp     Int19h_JumpToBootSector
+    ; Fall to JumpToBootSector
+
+;--------------------------------------------------------------------
+; JumpToBootSector
+;   Parameters:
+;       DL:     Drive to boot from (translated, 00h or 80h)
+;       ES:BX:  Ptr to boot sector
+;   Returns:
+;       Never returns
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+JumpToBootSector:
+    push    es                              ; Push boot sector segment
+    push    bx                              ; Push boot sector offset
+    call    ClearSegmentsForBoot
+    xor     dh, dh                          ; Device supported by INT 13h
+    retf
 
 
@@ -71 +82 @@
 Int19hMenu_RomBoot:
     call    BootVars_SwitchBackToPostStack
-    call    Int19h_ClearSegmentsForBoot
+    call    ClearSegmentsForBoot
     int     INTV_BOOT_FAILURE       ; Never returns
+
+
+;--------------------------------------------------------------------
+; ClearSegmentsForBoot
+;   Parameters:
+;       Nothing
+;   Returns:
+;       DS=ES:  Zero
+;   Corrupts registers:
+;       AX
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+ClearSegmentsForBoot:
+    xor     ax, ax
+    mov     ds, ax
+    mov     es, ax
+    ret