Changeset 121 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS

Timestamp:

Feb 28, 2011, 5:13:38 PM (14 years ago)

Author:

Tomi Tilli

google:author:

aitotat

Message:

Changes to XTIDE Universal BIOS:

• Endianness is now corrected for ATA device names.
• Converted all BootVars.asm functions to macros in BootVars.inc.
• Display library is now initialized second time before trying to display boot menu.

Location:

trunk/XTIDE_Universal_BIOS

Files:

• Inc/BootVars.inc (modified) (1 diff)
• Src/Boot/BootInfo.asm (modified) (1 diff)
• Src/Boot/BootVars.asm (deleted)
• Src/Handlers/Int19hMenu.asm (modified) (6 diffs)
• Src/Main.asm (modified) (1 diff)

trunk/XTIDE_Universal_BIOS/Inc/BootVars.inc

@@ -32 +32 @@
 
 
+;--------------------------------------------------------------------
+; Stores POST stack pointer to BOOTVARS.
+;
+; STORE_POST_STACK_POINTER
+;   Parameters:
+;       DS:     BDA and Interrupt Vector segment (zero)
+;   Returns:
+;       Nothing
+;   Corrupts registers:
+;       Nothing
+;--------------------------------------------------------------------
+%macro STORE_POST_STACK_POINTER 0
+    mov     [BOOTVARS.dwPostStack], sp
+    mov     [BOOTVARS.dwPostStack+2], ss
+%endmacro
+
+
+;--------------------------------------------------------------------
+; Initializes stack for boot menu usage.
+; POST stack is not large enough when DPTs are stored to 30:0h.
+;
+; Note regarding LOAD_BDA_SEGMENT_TO: If you force the use of SP
+; then you also have to unconditionally enable the CLI/STI pair.
+; The reason for this is that only some buggy 808x CPU:s need the
+; CLI/STI instruction pair when changing stacks. Other CPU:s disable
+; interrupts automatically when SS is modified for the duration of
+; the immediately following instruction to give time to change SP.
+;
+; SWITCH_TO_BOOT_MENU_STACK
+;   Parameters:
+;       Nothing
+;   Returns:
+;       SS:SP:  Pointer to top of Boot Menu stack
+;   Corrupts registers:
+;       Nothing
+;--------------------------------------------------------------------
+%macro SWITCH_TO_BOOT_MENU_STACK 0
+%ifndef USE_186
+    cli                                 ; Disable interrupts
+%endif
+    LOAD_BDA_SEGMENT_TO ss, sp
+    mov     sp, BOOTVARS.rgbMnuStack    ; Load offset to stack
+%ifndef USE_186
+    sti                                 ; Enable interrupts
+%endif
+%endmacro
+
+
+;--------------------------------------------------------------------
+; Restores SS and SP to initial boot loader values.
+;
+; Before doing any changes, see the note regarding
+; LOAD_BDA_SEGMENT_TO in BootVars_SwitchToBootMenuStack
+;
+; SWITCH_BACK_TO_POST_STACK
+;   Parameters:
+;       Nothing
+;   Returns:
+;       SS:SP:  Ptr to POST stack
+;   Corrupts registers:
+;       Nothing
+;--------------------------------------------------------------------
+%macro SWITCH_BACK_TO_POST_STACK 0
+%ifndef USE_386
+    cli                                 ; Disable interrupts
+    LOAD_BDA_SEGMENT_TO ss, sp
+    mov     sp, [ss:BOOTVARS.dwPostStack]
+    mov     ss, [ss:BOOTVARS.dwPostStack+2]
+    sti                                 ; Enable interrupts
+%else
+    LOAD_BDA_SEGMENT_TO ss, sp
+    lss     sp, [ss:BOOTVARS.dwPostStack]
+%endif
+%endmacro
+
+
 %endif ; BOOTVARS_INC

trunk/XTIDE_Universal_BIOS/Src/Boot/BootInfo.asm

@@ -67 +67 @@
     add     si, BYTE ATA1.strModel      ; DS:SI now points drive name
     lea     di, [bx+BOOTNFO.szDrvName]  ; ES:DI now points to name destination
-    mov     cx, LEN_BOOTNFO_DRV
-    call    Memory_CopyCXbytesFromDSSItoESDI
+    mov     cx, LEN_BOOTNFO_DRV / 2     ; Max number of WORDs allowed
+.CopyNextWord:
+    lodsw
+    xchg    al, ah                      ; Change endianness
+    stosw
+    loop    .CopyNextWord
     xor     ax, ax
     stosb                               ; Terminate with NULL

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int19hMenu.asm

@@ -18 +18 @@
 ALIGN JUMP_ALIGN
 Int19hMenu_BootLoader:
+    ; Store POST stack pointer
     LOAD_BDA_SEGMENT_TO ds, ax
-    call    BootVars_StorePostStackPointer
+    STORE_POST_STACK_POINTER
 
     ; Install new INT 19h handler now that BOOTVARS has been initialized
@@ -35 +36 @@
 ALIGN JUMP_ALIGN
 DisplayBootMenu:
-    call    BootVars_SwitchToBootMenuStack
+    SWITCH_TO_BOOT_MENU_STACK
+    CALL_DISPLAY_LIBRARY InitializeDisplayContext
     call    RamVars_GetSegmentToDS
     ; Fall to .ProcessMenuSelectionsUntilBootable
@@ -52 +54 @@
     call    BootSector_TryToLoadFromDriveDL
     jnc     SHORT .ProcessMenuSelectionsUntilBootable   ; Boot failure, show menu again
-    call    BootVars_SwitchBackToPostStack
+    SWITCH_BACK_TO_POST_STACK
     ; Fall to JumpToBootSector
 
@@ -68 +70 @@
     push    bx                              ; Push boot sector offset
     call    ClearSegmentsForBoot
-    xor     dh, dh                          ; Device supported by INT 13h
     retf
 
@@ -81 +82 @@
 ALIGN JUMP_ALIGN
 Int19hMenu_RomBoot:
-    call    BootVars_SwitchBackToPostStack
+    SWITCH_BACK_TO_POST_STACK
     call    ClearSegmentsForBoot
     int     INTV_BOOT_FAILURE       ; Never returns
@@ -91 +92 @@
 ;       Nothing
 ;   Returns:
+;       DX:     Zero
 ;       DS=ES:  Zero
 ;   Corrupts registers:
-;       AX
+;       Nothing
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
 ClearSegmentsForBoot:
-    xor     ax, ax
-    mov     ds, ax
-    mov     es, ax
+    xor     dx, dx                  ; Device supported by INT 13h
+    mov     ds, dx
+    mov     es, dx
     ret

trunk/XTIDE_Universal_BIOS/Src/Main.asm

@@ -117 +117 @@
 
 ; Include .asm files (boot menu)
-%include "BootVars.asm"         ; For accessing BOOTVARS struct
 %include "BootMenu.asm"         ; For Boot Menu operations
 %include "BootMenuEvent.asm"    ; For menu library event handling