causeway: cleanup code

update comments use new macros to do code more readable
jmalak · Jan 26, 2025 · bc9d850 · bc9d850
1 parent 5367f7d
commit bc9d850
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Showing 7 changed files with 131 additions and 99 deletions.
diff --git a/bld/causeway/asm/api.asm b/bld/causeway/asm/api.asm
@@ -158,7 +158,8 @@ api1_GotCall:
         movzx   ebp,bp
         mov     esi,Int_Flags16
 api1_32Bit0:
-        and     BYTE PTR ss:[ebp+esi],not EFLAG_CF  ;clear carry.
+        ;clear CF (carry).
+        and     BYTE PTR ss:[ebp+esi],not EFLAG_CF
         cld                                         ;Default direction.
         test    WORD PTR ss:[ebp+esi],EFLAG_IF      ;Were interrupts enabled?
         jz      api1_NoInts
@@ -847,7 +848,8 @@ medUse32Bit8:
 
 medUse16Bit8:
         mov     ax,ss:[ebp+ebx]
-        and     ax,NOT (EFLAG_IF or EFLAG_TF)       ;clear Trap and INT flag.
+        ;clear IF & TF (Trap and INT).
+        and     ax,NOT (EFLAG_IF or EFLAG_TF)
         mov     es:RealRegsStruc.Real_Flags[edi],ax ; explicitly set flags on DPMI 300h call
 
         assume ds:_apiCode
@@ -886,8 +888,10 @@ api15_Use32Bit8:
         mov     ebx,Int_Flags32
 api15_Use16Bit8:
         mov     ax,ss:[ebp+ebx]
-        and     ax,EFLAG_IF or EFLAG_DF                                     ;retain IF & DF.
-        and     es:RealRegsStruc.Real_Flags[edi],NOT (EFLAG_IF or EFLAG_DF) ;lose IF & DF.
+        ;retain IF & DF.
+        and     ax,EFLAG_IF or EFLAG_DF
+        ;clear IF & DF.
+        and     es:RealRegsStruc.Real_Flags[edi],NOT (EFLAG_IF or EFLAG_DF)
         or      es:RealRegsStruc.Real_Flags[edi],ax
         ret
 cwAPI_IntXX     endp
@@ -961,8 +965,10 @@ api16_Use32Bit8:
         mov     ebx,Int_Flags32
 api16_Use16Bit8:
         mov     ax,ss:[ebp+ebx]
-        and     ax,EFLAG_IF or EFLAG_DF                                     ;retain IF & DF.
-        and     es:RealRegsStruc.Real_Flags[edi],NOT (EFLAG_IF or EFLAG_DF) ;lose IF & DF.
+        ;retain IF & DF.
+        and     ax,EFLAG_IF or EFLAG_DF
+        ;clear IF & DF.
+        and     es:RealRegsStruc.Real_Flags[edi],NOT (EFLAG_IF or EFLAG_DF)
         or      es:RealRegsStruc.Real_Flags[edi],ax
         ret
 cwAPI_FarCallReal endp

diff --git a/bld/causeway/asm/cw32.asm b/bld/causeway/asm/cw32.asm
@@ -2164,8 +2164,10 @@ nosse:
         push    edx                     ;ESP
         pushfd                          ;EFlags
         pop     eax
-        and     ax,NOT (EFLAG_NT or EFLAG_IOPL) ;clear NT & IOPL.
-        or      ax,EFLAG_IOPL                   ;force IOPL 3.
+        ;clear NT & IOPL.
+        and     ax,NOT (EFLAG_NT or EFLAG_IOPL)
+        ;force IOPL 3.
+        or      ax,EFLAG_IOPL
         push    eax
         popfd
         push    eax
@@ -5108,7 +5110,7 @@ MakeDesc        endp
 ;
 ;On Entry:-
 ;
-;ES:DI  - Descriptor entry to use.
+;ES:EDI - Descriptor entry to use.
 ;ESI    - Linear base to set.
 ;ECX    - limit in bytes.
 ;AL     - Code size bit.

diff --git a/bld/causeway/asm/int21h.asm b/bld/causeway/asm/int21h.asm
@@ -123,7 +123,8 @@ Int21h  proc    near
         mov     esi,Int_Flags16
 int211_32Bit0:
         add     esi,ebp
-        and     BYTE PTR ss:[esi],not EFLAG_CF
+        ;clear CF (carry)
+        and     BYTE PTR ss:[esi],NOT EFLAG_CF
         cld                     ;Default direction.
         test    WORD PTR ss:[esi],EFLAG_IF  ;Were interrupts enabled?
         jz      int211_NoInts
@@ -1109,7 +1110,7 @@ int2121_Ef15:
         ;
         pop     ax
 int2121_Ef13:
-        and     ax,EFLAG_CF
+        and     al,EFLAG_CF
         call    Int21hAL2Carry
         ret
 Int21hExecFile  endp

diff --git a/bld/causeway/asm/interrup.asm b/bld/causeway/asm/interrup.asm
@@ -1078,7 +1078,8 @@ inter15_Int:
         push    ax
         xor     eax,eax
         mov     ax,[ebx+(4+4+4+4+4)+IFrame16.i16_flags] ;get flags again.
-        and     ax,NOT (EFLAG_IF or EFLAG_TF)           ;lose IF & TF
+        ;clear IF & TF
+        and     ax,NOT (EFLAG_IF or EFLAG_TF)
         push    eax             ;int handler flags.
         jmp     inter15_i2Use0
         ;
@@ -1094,7 +1095,8 @@ inter15_i2Use32:
         mov     eax,[ebx+(4+4+4+4+4)+IFrame.i_eip]      ;get IP
         push    eax
         mov     eax,[ebx+(4+4+4+4+4)+IFrame.i_eflags]   ;get flags again.
-        and     ax,NOT (EFLAG_IF or EFLAG_TF)           ;lose IF & TF
+        ;clear IF & TF
+        and     ax,NOT (EFLAG_IF or EFLAG_TF)
         push    eax             ;int handler flags.
         ;
 inter15_i2Use0:
@@ -1230,6 +1232,7 @@ IntDispatch     proc    near
         push    ds
         mov     ax,DpmiEmuDS
         mov     ds,ax
+        ;clear IF & TF.
         and     w[ExceptionFlags],NOT (EFLAG_IF or EFLAG_TF)
         mov     esi,ExceptionIndex      ;Get the exception number.
         add     esi,esi         ;*2
@@ -1302,8 +1305,10 @@ inter17_Resume:
         ;
         movzx   ebx,bx
         lss     sp,d[ebx+(4+4+4+4)+IFrame16.i16_sp] ;get old stack address.
-        and     w[ebx+(4+4+4+4)+IFrame16.i16_flags],EFLAG_IF or EFLAG_TF or EFLAG_DF ;retain IF & TF & DF.
-        and     w[ebx+(4+4+4)],NOT (EFLAG_IF or EFLAG_TF or EFLAG_DF) ;lose IF & TF & DF.
+        ;retain IF & TF & DF.
+        and     w[ebx+(4+4+4+4)+IFrame16.i16_flags],EFLAG_IF or EFLAG_TF or EFLAG_DF
+        ;clear IF & TF & DF.
+        and     w[ebx+(4+4+4)],NOT (EFLAG_IF or EFLAG_TF or EFLAG_DF)
         mov     ax,[ebx+(4+4+4)]
         or      ax,[ebx+(4+4+4+4)+IFrame16.i16_flags]
         push    ax              ;EFlags.
@@ -1330,8 +1335,10 @@ inter17_Resume:
         ;
 inter17_Use32:
         lss     esp,f[ebx+(4+4+4+4)+IFrame.i_esp] ;get old stack address.
-        and     w[ebx+(4+4+4+4)+IFrame.i_eflags],EFLAG_IF or EFLAG_TF or EFLAG_DF ;retain IF & TF & DF.
-        and     w[ebx+(4+4+4)],NOT (EFLAG_IF or EFLAG_TF or EFLAG_DF) ;lose IF & TF & DF.
+        ;retain IF & TF & DF.
+        and     w[ebx+(4+4+4+4)+IFrame.i_eflags],EFLAG_IF or EFLAG_TF or EFLAG_DF
+        ;clear IF & TF & DF.
+        and     w[ebx+(4+4+4)],NOT (EFLAG_IF or EFLAG_TF or EFLAG_DF)
         mov     eax,[ebx+(4+4+4)]
         or      eax,[ebx+(4+4+4+4)+IFrame.i_eflags]
         push    eax             ;EFlags.
@@ -1542,7 +1549,8 @@ inter18_c2:
         ;Now pass control to the INT simulator.
         ;
         mov     eax,[ebp+(4+4+4+4+4+4+4+4)+(10*2)+(4+4+4+4)]
-        and     eax,0ffffh and NOT (EFLAG_IF or EFLAG_TF or EFLAG_DF)
+        ;clear IF & TF & DF.
+        and     ax,NOT (EFLAG_IF or EFLAG_TF or EFLAG_DF)
         push    eax
         popfd
         mov     ebx,edx
@@ -1565,12 +1573,14 @@ inter18_NoCall:
         ;Update the flags.
         ;
         mov     ax,es:RealRegsStruc.Real_Flags[edi]
-        and     ax,NOT (EFLAG_NT or EFLAG_IOPL or EFLAG_IF or EFLAG_TF or EFLAG_DF) ;lose IF & TF & DF & NT & IOPL.
+        ;clear IF & TF & DF & NT & IOPL.
+        and     ax,NOT (EFLAG_NT or EFLAG_IOPL or EFLAG_IF or EFLAG_TF or EFLAG_DF)
         ;
         test    BYTE PTR DpmiEmuSystemFlags,1
         jz      inter18_Use32Bit
         mov     bx,[ebp+(4+4+4+4+4+4+4+4)+(10*2)+(4+4+4+4)+(4+4+4)+IFrame16.i16_flags]
-        and     bx,EFLAG_NT or EFLAG_IOPL or EFLAG_IF or EFLAG_TF or EFLAG_DF ;retain IF & TF & DF & NT & IOPL.
+        ;retain IF & TF & DF & NT & IOPL.
+        and     bx,EFLAG_NT or EFLAG_IOPL or EFLAG_IF or EFLAG_TF or EFLAG_DF
         or      ax,bx
         mov     [ebp+(4+4+4+4+4+4+4+4)+(10*2)+(4+4+4+4)+(4+4+4)+IFrame16.i16_flags],ax
         popad
@@ -1585,7 +1595,8 @@ inter18_NoCall:
         ;
 inter18_Use32Bit:
         mov     bx,[ebp+(4+4+4+4+4+4+4+4)+(10*2)+(4+4+4+4)+(4+4+4)+IFrame.i_eflags]
-        and     bx,EFLAG_NT or EFLAG_IOPL or EFLAG_IF or EFLAG_TF or EFLAG_DF ;retain IF & TF & DF & NT & IOPL.
+        ;retain IF & TF & DF & NT & IOPL.
+        and     bx,EFLAG_NT or EFLAG_IOPL or EFLAG_IF or EFLAG_TF or EFLAG_DF
         or      ax,bx
         mov     [ebp+(4+4+4+4+4+4+4+4)+(10*2)+(4+4+4+4)+(4+4+4)+IFrame.i_eflags],ax
         popad

diff --git a/bld/causeway/asm/ldt.asm b/bld/causeway/asm/ldt.asm
@@ -298,7 +298,7 @@ RawSetSelType   proc    near
         mov     ax,KernalZero   ;make LDT addresable.
         mov     es,ax
         movzx   esi,bx          ;Get the selector.
-        GetDescIndex esi        ;lose RPL & TI.
+        ClearDescTIRPL esi        ;lose RPL & TI.
         add     esi,MDTLinear   ;offset into descriptor table.
         mov     BYTE PTR es:[esi+5],cl
         and     ch,11110000b
@@ -337,7 +337,7 @@ RawSetSelLimit  proc    near
         mov     ax,KernalZero           ;make LDT addresable.
         mov     es,ax
         movzx   esi,bx                  ;Get the selector.
-        GetDescIndex esi                ;lose RPL & TI.
+        ClearDescTIRPL esi                ;lose RPL & TI.
         add     esi,MDTLinear           ;offset into descriptor table.
         shl     ecx,16                  ;cx:dx -> ecx
         mov     cx,dx                   ;/
@@ -384,7 +384,7 @@ RawSetSelBase   proc    near
         mov     ax,KernalZero           ;make LDT addressable.
         mov     es,ax
         movzx   esi,bx                  ;Get the selector.
-        GetDescIndex esi                ;lose RPL & TI.
+        ClearDescTIRPL esi                ;lose RPL & TI.
         add     esi,MDTLinear           ;offset into descriptor table.
         mov     es:[esi+4],cl           ;base mid.
         mov     es:[esi+7],ch           ;base high.
@@ -423,7 +423,7 @@ RawGetSelBase   proc    near
         mov     ax,KernalZero   ;make LDT addresable.
         mov     es,ax
         movzx   esi,bx          ;Get the selector.
-        GetDescIndex esi        ;lose RPL & TI.
+        ClearDescTIRPL esi        ;lose RPL & TI.
         add     esi,MDTLinear   ;offset into descriptor table.
         mov     cl,es:[esi+4]   ;base mid.
         mov     ch,es:[esi+7]   ;base high.
@@ -459,7 +459,7 @@ RawBPutDescriptor proc near
         mov     ds,ax
         assume ds:_cwRaw
         movzx   esi,bx          ;Get the selector.
-        GetDescIndex esi        ;lose RPL & TI.
+        ClearDescTIRPL esi        ;lose RPL & TI.
         add     esi,MDTLinear   ;offset into descriptor table.
         test    BYTE PTR RawSystemFlags,1
         jz      ldt8_Use32
@@ -511,7 +511,7 @@ RawBGetDescriptor proc near
         mov     ds,ax
         assume ds:_cwRaw
         movzx   esi,bx          ;Get the selector.
-        GetDescIndex esi        ;lose RPL & TI.
+        ClearDescTIRPL esi        ;lose RPL & TI.
         add     esi,MDTLinear   ;offset into descriptor table.
         test    BYTE PTR RawSystemFlags,1
         jz      ldt9_Use32