1 files changed, 288 insertions, 0 deletions

diff --git a/v4.0/src/DOS/SEGCHECK.ASM b/v4.0/src/DOS/SEGCHECK.ASM
new file mode 100644
index 0000000..992eac2
--- /dev/null
+++ b/v4.0/src/DOS/SEGCHECK.ASM
@@ -0,0 +1,288 @@
+;       SCCSID = @(#)segcheck.asm       1.2 85/07/24
+TITLE   SegCheck - internal consistency check
+NAME    SegCheck
+
+.xlist
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+
+ShareF  = FALSE
+
+IF NOT SHAREF
+include dosseg.asm
+ENDIF
+.list
+
+AsmVars <NET, DEBUG>
+
+DEBUG   = FALSE
+
+IF NOT SHAREF
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+ASSUME  CS:DOSGroup
+ELSE
+SHARE   SEGMENT BYTE PUBLIC  'SHARE'
+ASSUME  CS:SHARE
+ENDIF
+
+DEBUG   = FALSE
+
+BREAK   <SegCheck - validate segments in MSDOS>
+
+Off Macro   reg,var
+IF SHAREF
+        mov     reg,offset var
+else
+        mov     reg,offset DOSGroup:var
+endif
+endm
+
+zfmt    MACRO   fmts,args
+local   a,b
+        PUSHF
+        PUSH    AX
+        PUSH    BP
+        MOV     BP,SP
+If (not sharef) and (not redirector)
+Table   segment
+a       db      fmts,0
+Table   ends
+        MOV     AX,OFFSET DOSGROUP:a
+else
+        jmp     short b
+a       db      fmts,0
+if sharef
+b:      mov     ax,offset share:a
+else
+b:      mov     ax,offset netwrk:a
+endif
+endif
+        PUSH    AX
+cargs = 2
+IRP item,<args>
+IFIDN   <AX>,<item>
+        MOV     AX,[BP+2]
+ELSE
+        MOV     AX,item
+ENDIF
+        PUSH    AX
+cargs = cargs + 2
+ENDM
+        invoke  PFMT
+        ADD     SP,Cargs
+        POP     BP
+        POP     AX
+        POPF
+ENDM
+
+segFrame    Struc
+segbp       DW  ?
+segip       DW  ?
+segmes      dw  ?
+segtemp     DW  ?
+segFrame    ENDS
+;
+;   SegCheck - assure that segments are correctly set up
+;
+;   Inputs:     top of stack points to:
+;               2-byte jump
+;               byte flags 04h is ES 02h is DS 01 is CS/SS
+;               offset asciz message
+;
+;   Outputs:    message to screen (via INT 29h)
+;   Nothing modified (flags too)
+
+Procedure   SegCheck,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        SaveReg <BP>
+        MOV     BP,SP                   ; set up addressing
+        PUSHF
+        SaveReg <AX,BX,CX,DX>
+        MOV     AL,BYTE PTR [BP].segtemp; get flags
+        MOV     CX,SS
+        TEST    AL,1                    ; shall we use CS or SS?
+        JZ      SegUseSS                ; use SS
+        MOV     CX,CS                   ; use CS instead
+SegUseSS:
+        TEST    AL,2                    ; do we check DS?
+        JZ      SegTestES               ; no, go check ES
+        MOV     DX,DS
+        CMP     CX,DX
+        JZ      SegTestES               ; DS is valid, go check ES
+        MOV     AX,[BP].segmes
+        zfmt    <"Assumed DS invalid $s\n">,<AX>
+SegTestES:
+        TEST    AL,4                    ; do we check ES?
+        JZ      SegTestDone             ; no, all done
+        MOV     DX,ES
+        CMP     CX,DX
+        JZ      SegTestDone             ; ES is valid, all done
+        MOV     AX,[BP].segmes
+        zfmt    <"Assumed ES invalid $s\n">,<AX>
+SegTestDone:
+        RestoreReg  <DX,CX,BX,AX>
+        POPF
+        RestoreReg  <BP>
+        ret     4                       ; release message, temp
+EndProc SegCheck
+
+
+IF NOT SHAREF
+I_need  DPBHead,DWORD
+I_need  BuffHead,DWORD
+I_need  sftFCB,DWORD
+I_need  AuxStack,BYTE
+I_need  IOStack,BYTE
+I_need  renbuf,byte
+I_need  CurrentPDB,WORD
+I_need  User_In_AX,WORD
+
+extrn   ECritDisk:NEAR
+
+CritNOP label   byte
+        RET
+
+AstFrame    STRUC
+Astbp       dw  ?
+Astip       dw  ?
+Astmes      dw  ?
+Astarg      dd  ?
+AstFrame    ENDS
+
+Public SGCHK001S,SGCHK001E
+SGCHK001S label byte
+DPBMes  DB  "DPB assertion failed: ",0
+BUFMes  DB  "BUF assertion failed: ",0
+SFTMes  DB  "SFT assertion failed: ",0
+BlankSp DB  " ",0
+Colon   DB  ":",0
+
+Msg     DW  ?
+
+SGCHK001E label byte
+
+Table   segment
+    Extrn SectPDB:WORD, SectRef:WORD
+Table   ends
+
+;   DPBCheck - validate a supposed DPB pointer
+;   Inputs:     Pushed arguments
+;   Outputs:    Message to screen
+;   Registers modified: none
+
+Procedure   DPBCheck,NEAR
+        MOV     Msg,OFFSET DOSGroup:DPBMes
+        SaveReg <BP>
+        MOV     BP,SP
+        PUSHF
+        SaveReg <AX,BX,DS,SI,ES,DI>
+        LES     DI,DPBHead
+        LDS     SI,[BP].Astarg
+DPBLoop:CMP     DI,-1
+        JZ      DPBNotFound
+        invoke  PointComp
+        JZ      DPBRet
+        LES     DI,ES:[DI.dpb_next_dpb]
+        JMP     DPBLoop
+DPBNotFound:
+        MOV     AX,[BP].Astmes
+        zfmt    <"$s$x:$x $s\n">,<msg,ds,si,AX>
+        CLI
+a:      JMP     a                       ; slam the door.
+DPBRet: RestoreReg  <DI,ES,SI,DS,BX,AX> ;   Done:
+        POPF
+        RestoreReg  <BP>
+        RET     6
+EndProc DPBCheck
+
+;   SFTCheck - validate a supposed SFT pointer
+;   Inputs:     Pushed arguments
+;   Outputs:    Message to screen
+;   Registers modified: none
+
+Procedure   SFTCheck,NEAR
+        MOV     Msg,OFFSET DOSGroup:SFTMes
+        SaveReg <BP>
+        MOV     BP,SP
+        PUSHF
+        SaveReg <AX,BX,DS,SI,ES,DI>
+        LDS     SI,[BP].Astarg
+        XOR     BX,BX                   ;   i = 0;
+SFTLoop:
+        SaveReg <BX>
+        invoke  SFFromSFN               ;   while ((d=SF(i)) != NULL)
+        RestoreReg  <BX>
+        JC      Sft1
+        invoke  PointComp
+        JZ      DPBRet                  ;               goto Done;
+SFTNext:INC     BX                      ;           else
+        JMP     SFTLoop                 ;               i++;
+SFT1:   LES     DI,sftFCB
+        MOV     BX,ES:[DI.sfCount]
+        LEA     DI,[DI.sfTable]
+SFT2:
+        invoke  PointComp
+DPBRETJ:JZ      DPBRet
+        ADD     DI,SIZE sf_entry
+        DEC     BX
+        JNZ     SFT2
+;
+; The SFT is not in the allocated tables.  See if it is one of the static
+; areas.
+;
+        Context ES
+        MOV     DI,OFFSET DOSGROUP:AUXSTACK - SIZE SF_ENTRY
+        Invoke  PointComp
+        JZ      DPBRet
+        MOV     DI,OFFSET DOSGROUP:RenBuf
+        Invoke  PointComp
+        JZ      DPBRetj
+DPBNotFoundJ:
+        JMP     DPBNotFound
+EndProc SFTCheck
+
+;   BUFCheck - validate a supposed BUF pointer
+;   Inputs:     Pushed arguments
+;   Outputs:    Message to screen
+;   Registers modified: none
+
+Procedure   BUFCheck,NEAR
+        MOV     Msg,OFFSET DOSGroup:BUFMes
+        SaveReg <BP>
+        MOV     BP,SP
+        PUSHF
+        SaveReg <AX,BX,DS,SI,ES,DI>
+;
+; CheckDisk - make sure that we are in the disk critical section...
+;
+        MOV     AL,BYTE PTR ECritDisk
+        CMP     AL,CritNOP
+        JZ      CheckDone
+        MOV     AX,CurrentPDB
+        CMP     SectPDB + 2 * critDisk,AX
+        MOV     AX,[BP].astmes
+        JZ      CheckRef
+        zfmt    <"$p: $x $s critDisk owned by $x\n">,<User_In_AX,AX,SectPDB+2*critDisk>
+CheckRef:
+        CMP     SectRef + 2 * critDisk,0
+        JNZ     CheckDone
+        zfmt    <"$p: $x $s critDisk ref count is 0\n">,<User_In_AX,AX>
+CheckDone:
+
+        LDS     SI,[BP].Astarg
+        LES     DI,BUFFHead
+BUFLoop:CMP     DI,-1
+        JZ      DPBNotFoundJ
+        invoke  PointComp
+        JNZ     BufNext
+        JMP     DPBRet
+BufNext:
+        LES     DI,ES:[DI.buf_link]
+        JMP     BUFLoop
+EndProc BUFCheck
+
+CODE    ENDS
+ELSE
+SHARE   ENDS
+ENDIF
+END