Changeset 102149 in vbox for trunk

Timestamp:

Nov 20, 2023 11:14:01 AM (15 months ago)

Author:

vboxsync

Message:

ValKit/bs3kit: Initial Bs3DiskQueryGeometry code. bugref:10371

File:

• trunk/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-DiskQueryGeometry.asm (copied) (copied from trunk/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-BiosInt15hE820.asm ) (6 diffs)

trunk/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-DiskQueryGeometry.asm

@@ -55 +55 @@
 BS3_BEGIN_TEXT16
 extern RT_CONCAT3(_Bs3SwitchTo,TMPL_MODE_UNAME,_Safe_rm)
+BS3_EXTERN_DATA16 g_aBs3RmIvtOriginal
 
 
 ;;
-; Performs a int 15h function 0xe820 call.
-;
-; @cproto   BS3_MODE_PROTO_STUB(bool, Bs3BiosInt15hE820,(INT15E820ENTRY BS3_FAR *pEntry, uint32_t BS3_FAR *pcbEntry,
-;                                                        uint32_t BS3_FAR *puContinuationValue));
-;
-; @returns Success indicator.
-; @param   pEntry              The return buffer.
-; @param   pcbEntry            Input: The size of the buffer (min 20 bytes);
-;                              Output: The size of the returned data.
-; @param   puContinuationValue Where to get and return the continuation value (EBX)
-;                              Set to zero the for the first call.  Returned as zero
-;                              after the last entry.
+; Performs a int 13h function 8 call.
+;
+; @cproto   BS3_MODE_PROTO_STUB(uint8_t, Bs3DiskQueryGeometry,(uint8_t bDrive, uint16_t *puMaxCylinder,
+;                                                              uint8_t *puMaxHead, uint8_t *puMaxSector));
+;
+; @returns  Register value (ax/eax). Zero on success, non-zero on failure.
+;
+; @uses     No GPRs (only return full register(s)). In 64-bit mode DS and ES is trashed.
 ;
 ; @remarks  ASSUMES we're in ring-0 when not in some kind of real mode.
 ; @remarks  ASSUMES we're on a 16-bit suitable stack.
 ;
-; @uses     rax
-;
 TMPL_BEGIN_TEXT
-BS3_PROC_BEGIN_MODE Bs3BiosInt15hE820, BS3_PBC_HYBRID
+BS3_PROC_BEGIN_MODE Bs3DiskQueryGeometry, BS3_PBC_HYBRID
         push    xBP
         mov     xBP, xSP
+;; @todo does not work on 286 and earlier!
         sPUSHF
         cli
@@ -87 +83 @@
         push    sSI
         push    sDI
-%ifdef TMPL_16BIT
+%ifndef TMPL_64BIT
         push    ds
         push    es
 %endif
+
         ; Load/Save parameters.
-%define a_pEntry              [xBP + xCB + cbCurRetAddr + sCB*0]
-%define a_pcbEntry            [xBP + xCB + cbCurRetAddr + sCB*1]
-%define a_puContinuationValue [xBP + xCB + cbCurRetAddr + sCB*2]
+%define a_bDrive                [xBP + xCB + cbCurRetAddr + xCB*0]
+%define a_puMaxCylinder         [xBP + xCB + cbCurRetAddr + xCB + sCB*0]
+%define a_pMaxHead              [xBP + xCB + cbCurRetAddr + xCB + sCB*1]
+%define a_puMaxSector           [xBP + xCB + cbCurRetAddr + xCB + sCB*2]
+
 %ifdef TMPL_64BIT
-        mov     a_pEntry, rcx           ; save pEntry
-        mov     a_pcbEntry, rdx         ; save pcbEntry
-        mov     a_puContinuationValue, r8  ; save a_puContinuationValue
-        mov     ebx, [r8]               ; uContinuationValue for int15
-        mov     ecx, [rdx]              ; Buffer size for int15.
-%elifdef TMPL_16BIT
-        les     bx, a_pcbEntry
-        mov     ecx, [es:bx]            ; Buffer size for int15.
-        les     bx, a_puContinuationValue
-        mov     ebx, [es:bx]            ; Buffer size for int15.
+        mov     a_bDrive, rcx           ; save bDrive
+        mov     a_puMaxCylinder, rdx    ; save pcCylinders
+        mov     a_pMaxHead, r8          ; save pcHeads
+        mov     a_puMaxSector, r9       ; save pcSectors
+        movzx   edx, cl                 ; dl = drive
 %else
-        mov     ecx, a_pcbEntry
-        mov     ecx, [ecx]              ; Buffer size for int15.
-        mov     ebx, a_puContinuationValue
-        mov     ebx, [ebx]              ; uContinuationValue for int15
-%endif
-        ;
-        ; Check that the cbEntry isn't too big or too small before doing
-        ; the stack allocation.  (Our BIOS doesn't check if too small.)
-        ;
-        cmp     ecx, 100h
-        jae     .failed
-        cmp     cl, 14h
-        jb      .failed
-
-%if TMPL_MODE != BS3_MODE_RM
-        sub     xSP, xCX                ; allocate a temporary buffer on the stack.
-        and     xSP, ~0fh
-%endif
-
-        ;
-        ; Switch to real mode, first we just ot the 16-bit text segment.
+        mov     dl, a_bDrive            ; dl = drive
+%endif
+
+        ;
+        ; Switch to real mode, first we just to the 16-bit text segment.
         ; This preserve all 32-bit register values.
         ;
@@ -140 +118 @@
         BS3_SET_BITS 16
 %endif
+        ; Ralf Brown suggest setting es:di to NULL before the call. This is also helpful
+        ; wrt to IVT manipulation (next step).
+        xor     di, di
+        mov     es, di
+
+        ;
+        ; Save current and restore the original IVT[13h] entry.
+        ;
+        mov     si, seg g_aBs3RmIvtOriginal
+        mov     ds, si
+        mov     si, g_aBs3RmIvtOriginal
+
+        push    word [es:13h * 4]
+        mov     ax, [si + 13h * 4]
+        mov     [es:13h * 4], ax
+
+        push    word [es:13h * 4 + 2]
+        mov     ax, [si + 13h * 4 + 2]
+        mov     [es:13h * 4 + 2], ax
 
         ;
         ; Make the call.
         ;
-%if TMPL_MODE == BS3_MODE_RM
-        les     di, a_pEntry
-%else
-        push    ss                      ; es:di -> ss:sp
-        pop     es
-        mov     di, sp
-%endif
-        mov     edx, INT15_E820_SIGNATURE
-        mov     eax, 0e820h             ; BIOS function number
-        int     15h
+        mov     ax, 0800h                   ; ah=08h
+        xor     di, di                      ; ralf brown suggestion to guard against bios bugs.
+        mov     es, di
+        int     13h
+
+        ;
+        ; Restore the modified IVT[13h] entry.
+        ; Must not touch EFLAGS.CF!
+        ;
+        push    word 0
+        pop     ds
+        pop     word [ds:13h * 4 + 2]
+        pop     word [ds:13h * 4]
 
         ;
@@ -170 +170 @@
         ; Check that we didn't failed.
         ;
-        jc      .failed
-        cmp     eax, INT15_E820_SIGNATURE
-        jc      .failed
-        cmp     ecx, 20
-        jb      .failed
-
-        ;
-        ; Save the continuation value.
+        jc      .failed_return_ah
+
+        ;
+        ; Save the return values.
+        ;   CL[7:6]:CH = max cylinders.
+        ;   DH         = max heads
+        ;   CL[5:0]    = max sectors
+        ; Other stuff we don't care about:
+        ;   AH         = 0
+        ;   AL         = undefined/zero
+        ;   BL         = drive type
+        ;   DL         = max drives.
+        ;   ES:DI      = driver parameter table for floppies.
         ;
 %ifdef TMPL_16BIT
-        mov     eax, ebx
-        lds     bx, a_puContinuationValue
-        mov     [bx], eax
+        les     di, a_pMaxHead
+        mov     [es:di], dh
+
+        les     di, a_puMaxSector
+        mov     al, 3fh
+        and     al, cl
+        mov     [es:di], al
+
+        les     di, a_puMaxCylinder
+        shr     cl, 6
+        xchg    cl, ch
+        mov     [es:di], cx
 %else
-        mov     xAX, a_puContinuationValue
-        mov     [xAX], ebx
-%endif
-
-        ;
-        ; Save the entry size.
-        ;
-%ifdef TMPL_16BIT
-        lds     bx, a_pcbEntry
-%else
-        mov     xBX, a_pcbEntry
-%endif
-        mov     [xBX], ecx
-
-%if TMPL_MODE != BS3_MODE_RM
-        ;
-        ; Copy the returned stuff into the caller's buffer.
-        ;
-        mov     xSI, xSP
- %ifdef TMPL_16BIT
-        push    ss
-        pop     es
-        lds     di, a_pEntry
- %else
-        mov     xDI, a_pEntry
- %endif
-        cld
-        rep movsb
+        mov     xDI, a_pMaxHead
+        mov     [xDI], dh
+
+        mov     xDI, a_puMaxSector
+        mov     al, 3fh
+        and     al, cl
+        mov     [xDI], al
+
+        mov     xDI, a_puMaxCylinder
+        shr     cl, 6
+        xchg    cl, ch
+        mov     [xDI], cx
 %endif
 
@@ -217 +215 @@
         ; Return success
         ;
-        mov     al, 1
+        mov     al, 0
 
 .return:
-%ifdef TMPL_16BIT
+%ifndef TMPL_64BIT
         lea     xSP, [xBP - sCB * 6 - xCB*2]
         pop     es
@@ -239 +237 @@
         ; Failed.
         ;
-.failed:
-        xor     al, al
+.failed_return_ah:
+        mov     al, ah
+        cmp     al, 0
+        jne     .return
+        dec     al
         jmp     .return
 BS3_PROC_END_MODE   Bs3BiosInt15hE820