Eliminate magic numbers for volume dir key block, case bits

Introduce VolumeDirectoryHeader::case_bits rather than hardcoding the offset. Also, introduce FileEntry::case_bits alias for FileEntry::version and change some variable names to better match usage. No binary changes
a2stuff · Mar 17, 2024 · fb6b657 · fb6b657
1 parent b15b99e
commit fb6b657
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Showing 6 changed files with 28 additions and 24 deletions.
diff --git a/desktop.system/desktop.system.s b/desktop.system/desktop.system.s
@@ -2279,7 +2279,7 @@ PreserveQuitCode        := PreserveQuitCodeImpl::start
 
         rts                     ; not found
 
-        DEFINE_READ_BLOCK_PARAMS read_block_params, block_buffer, 2
+        DEFINE_READ_BLOCK_PARAMS read_block_params, block_buffer, kVolumeDirKeyBlock
 
 found:
         ;; Found it in DEVLST, X = index

diff --git a/desktop/main.s b/desktop/main.s
@@ -9254,7 +9254,7 @@ f35:    ldax    #dib_buffer+SPDIB::ID_String_Length
         ldy     #IconType::floppy800
         rts
 
-        DEFINE_READ_BLOCK_PARAMS block_params, block_buffer, 2
+        DEFINE_READ_BLOCK_PARAMS block_params, block_buffer, kVolumeDirKeyBlock
         unit_number := block_params::unit_num
 
 blocks: .word   0
@@ -11973,17 +11973,17 @@ failure:
     IF_EQ
         ;; Volume
         copy    DEVNUM, block_params::unit_num
-        copy16  #2, block_params::block_num
+        copy16  #kVolumeDirKeyBlock, block_params::block_num
         MLI_CALL READ_BLOCK, block_params
         bcs     ret
-        copy16  block_buffer + $1A, case_bits
+        copy16  block_buffer + VolumeDirectoryHeader::case_bits, case_bits
     ELSE
         ;; File
         ldax    #src_path_buf
         jsr     GetFileEntryBlock ; leaves $06 pointing at `FileEntry`
         bcs     ret
         entry_ptr := $06
-        ldy     #FileEntry::version
+        ldy     #FileEntry::case_bits
         copy16in (entry_ptr),y, case_bits
     END_IF
 
@@ -12005,7 +12005,7 @@ ret:    rts
         copy    DEVNUM, block_params::unit_num
         MLI_CALL READ_BLOCK, block_params
         bcs     ret
-        ldy     #FileEntry::version
+        ldy     #FileEntry::case_bits
         copy16in case_bits, (block_ptr),y
         MLI_CALL WRITE_BLOCK, block_params
 
@@ -12968,7 +12968,7 @@ match:  lda     flag
         eor     #$40            ; bit 6 = relink supported
 :       rts
 
-        DEFINE_READ_BLOCK_PARAMS block_params, block_buffer, 2
+        DEFINE_READ_BLOCK_PARAMS block_params, block_buffer, kVolumeDirKeyBlock
         block_params__unit_num := block_params::unit_num
 .endproc ; CheckMoveOrCopy
 
@@ -13102,7 +13102,7 @@ ShowErrorAlertDst       := ShowErrorAlertImpl::flag_set
 
         MLI_CALL READ_BLOCK, block_params
         bcs     fallback
-        ldy     #FileEntry::version
+        ldy     #FileEntry::case_bits
         copy16in #0, (block_ptr),y
 write_block:
         MLI_CALL WRITE_BLOCK, block_params
@@ -13141,10 +13141,10 @@ appleworks:
         ;; --------------------------------------------------
         ;; Wipe volume GS/OS case bits
 volume:
-        copy16  #2, block_number ; volume directory key block
+        copy16  #kVolumeDirKeyBlock, block_number
         MLI_CALL READ_BLOCK, block_params
         bcs     fallback
-        copy16  #0, block_buffer + $1A
+        copy16  #0, block_buffer + VolumeDirectoryHeader::case_bits
         jmp     write_block
 
         block_buffer := $800

diff --git a/desktop/ovl_format_erase.s b/desktop/ovl_format_erase.s
@@ -1004,7 +1004,7 @@ maybe_dos:
 
 ;;; Handle Pascal disk - name suffixed with ':'
 pascal_disk:
-        copy16  #$0002, read_block_params::block_num
+        copy16  #kVolumeDirKeyBlock, read_block_params::block_num
         MLI_CALL READ_BLOCK, read_block_params
         bcc     :+
         ;; Pascal disk, empty name - use " :" (weird, but okay?)

diff --git a/disk_copy/auxlc.s b/disk_copy/auxlc.s
@@ -1273,7 +1273,7 @@ match:  clc
         ptr := $06
 
         stax    ptr
-        copy16  #2, main__block_params_block_num
+        copy16  #kVolumeDirKeyBlock, main__block_params_block_num
         jsr     main__ReadBlock
     IF_CS
         ;; Just use a single space as the name
@@ -1385,17 +1385,17 @@ match:  clc
         ;; --------------------------------------------------
         ;; Check for GS/OS case bits, apply if found
 
-        copy16  #2, main__block_params_block_num
+        copy16  #kVolumeDirKeyBlock, main__block_params_block_num
         copy16  #default_block_buffer, main__block_params_data_buffer
         jsr     main__ReadBlock
         bcs     fallback
 
-        case_bytes := default_block_buffer + $1A
-        asl16   case_bytes
+        case_bits := default_block_buffer + VolumeDirectoryHeader::case_bits
+        asl16   case_bits
         bcc     fallback      ; High bit set = GS/OS case bits present
 
         ldy     #1
-bloop:  asl16   case_bytes      ; Shift out high byte first
+bloop:  asl16   case_bits       ; Shift out high byte first
         bcc     :+
         lda     (ptr),y
         ora     #AS_BYTE(~CASE_MASK)

diff --git a/inc/prodos.inc b/inc/prodos.inc
@@ -32,6 +32,8 @@ SELECTOR_ORG    := $1000        ; QUIT handler execution load address
 
 BLOCK_SIZE      = $200
 
+kVolumeDirKeyBlock = 2
+
 ;;; ============================================================
 ;;; Unit Numbers
 ;;; ============================================================
@@ -238,6 +240,7 @@ NAME_LENGTH_MASK        = $0F
         total_blocks    .word
 .endstruct
         .assert .sizeof(VolumeDirectoryHeader) = $2B, error, "incorrect struct size"
+        VolumeDirectoryHeader::case_bits = $1A
 
 ;;; Subdirectory Header structure
 .struct SubdirectoryHeader
@@ -280,6 +283,7 @@ NAME_LENGTH_MASK        = $0F
         header_pointer  .word
 .endstruct
         .assert .sizeof(FileEntry) = $27, error, "incorrect struct size"
+        FileEntry::case_bits = FileEntry::version
 
 ;;; ============================================================
 ;;; ProDOS Driver Protocol

diff --git a/lib/adjustfilecase.s b/lib/adjustfilecase.s
@@ -47,7 +47,7 @@ vol_name:
         bcs     fallback
         MLI_CALL CLOSE, volname_close_params
 
-        copy16  volbuf + $1A, version_bytes
+        copy16  volbuf + VolumeDirectoryHeader::case_bits, case_bits
         jmp     common
 
 ;;; --------------------------------------------------
@@ -67,12 +67,12 @@ file_entry:
         cmp     #FT_ASP
         beq     appleworks
 
-        ldy     #FileEntry::version
-        copy16in (ptr),y, version_bytes
+        ldy     #FileEntry::case_bits
+        copy16in (ptr),y, case_bits
         FALL_THROUGH_TO common
 
 common:
-        asl16   version_bytes
+        asl16   case_bits
         bcs     apply_bits      ; High bit set = GS/OS case bits present
 
 ;;; --------------------------------------------------
@@ -122,7 +122,7 @@ check_alpha:
 
 apply_bits:
         ldy     #1
-@bloop: asl16   version_bytes   ; NOTE: Shift out high byte first
+@bloop: asl16   case_bits   ; NOTE: Shift out high byte first
         bcc     :+
         lda     (ptr),y
         ora     #AS_BYTE(~CASE_MASK)
@@ -153,10 +153,10 @@ apply_bits:
 appleworks:
         ldy     #FileEntry::aux_type
         lda     (ptr),y
-        sta     version_bytes+1
+        sta     case_bits+1
         iny
         lda     (ptr),y
-        sta     version_bytes
+        sta     case_bits
         jmp     apply_bits
 
 ;;; --------------------------------------------------
@@ -168,7 +168,7 @@ file_name:
 
 ;;; --------------------------------------------------
 
-version_bytes:
+case_bits:
         .word   0
 .endproc ; AdjustCaseImpl