cpm: cache syscall vector for apps that reuse the RST vector

diff --git a/Applications/cpm/README b/Applications/cpm/README
index 0713de8..706fad5 100644 (file)
--- a/Applications/cpm/README
+++ b/Applications/cpm/README
@@ -5,16 +5,10 @@ into userspace.
 
 TODO:
 
--      Start debugging it
--      Check all syscall translations are still correct
--      Move what we can into the runcpm loader binary
--      Support tacking .COM onto the name in runcpm
 -      Fix up directory mapping and shrink buffer
 -      Use CP/M scratch space for internal variables and buffer pointers
        so we can also support a high loaded version using shared common for
        awkward memory mapped boxes (eg the Memotech)
--      Save the syscall vector on entry as CP/M apps can re-use the RST
-       vector
 -      Find a nice way to build a relocatable version rather than one per
        system type.
 

diff --git a/Applications/cpm/emulator.s b/Applications/cpm/emulator.s
index cfcffbb..71ef724 100644 (file)
--- a/Applications/cpm/emulator.s
+++ b/Applications/cpm/emulator.s
@@ -6,10 +6,7 @@
     ;
     ;
     ; TODO
-    ; - Recheck all syscall translations
     ; - Fix up directory mapping a bit more
-    ; - Save the syscall vector on entry and go via the saved copy as the
-    ;   RST could be re-used by CP/M programs
     ; - Make the code use indirect pointers to the directory buffer etc
     ;   from the scratch space so that we can eventually make it
     ;   multi-threaded for boxes with a large fixed common where we want to
@@ -87,6 +84,11 @@ EStart:
        LD      HL,#0
        LD      (0x0003),HL     ; Clear IOBYTE and Default Drive/User
 
+       LD      HL, (0x31)              ; JP xxxx is what FUZIX leaves at 0x30
+       LD      (syscall+1), HL
+       LD      A, #0xC3                ; JP
+       LD      (syscall), A
+
        JP      __bios          ; Go to Cold Start setup
 
 ;==========================================================
@@ -431,7 +433,7 @@ OpenF:      PUSH    DE              ; Mode
        PUSH    HL              ;  Path
        LD      HL,#1           ;   Fuzix Open Fcn #
        PUSH    HL
-       RST     0x30            ;    _open (Path, Mode);
+       CALL    syscall         ;    _open (Path, Mode);
        POP     BC              ; Clean Stack
        POP     BC
        POP     BC
@@ -450,7 +452,7 @@ Fcn16:      LD      IY,(_arg)
 
        LD      HL,#11          ; Fuzix sync function #
        PUSH    HL
-       RST     0x30            ; Execute!
+       CALL    syscall         ; Execute!
        POP     BC              ; Clean Stack
 
        JP      Exit0           ; Return OK
@@ -461,7 +463,7 @@ Fcn16:      LD      IY,(_arg)
 CloseV:        PUSH    DE
        LD      HL,#2           ;  Fuzix Close Fcn #
        PUSH    HL
-       RST     0x30            ;   Execute!
+       CALL    syscall         ;   Execute!
        POP     BC              ; Clean Stack
        POP     BC
        RET
@@ -537,7 +539,7 @@ Fcn19:      CALL    CkSrch          ; Ensure Search file closed
        PUSH    HL              ; String
        LD      HL,#6           ;  UZI Unlink Fcn #
        PUSH    HL
-       RST     0x30            ;   Execute!
+       CALL    syscall         ;   Execute!
        POP     BC              ; Clean Stack
        POP     BC
 
@@ -681,14 +683,14 @@ Fcn21A:   CALL    DoWrite         ;   Write
 ;     desc = creat (getname (blk), 0666);
 
 Fcn22: CALL    CkSrch          ; Ensure Search file closed
-       LD      HL,#0q0666      ; Own/Grp/Oth are Read/Execute
+       LD      HL,#0x1B6       ; Own/Grp/Oth are Read/Execute
        PUSH    HL              ; DE -> arg
        LD      HL,#0x502       ; O_CREAT|O_RDWR|O_TRUNC
        CALL    GetNam          ;  This name string
        PUSH    HL
        LD      HL,#1           ;   Fuzix open Fcn #
        PUSH    HL
-       RST     0x30            ;    Execute!
+       CALL    syscall         ;    Execute!
        POP     BC              ; Clean Stack
        POP     BC
        POP     BC
@@ -742,7 +744,7 @@ Fcn23:      CALL    CkSrch          ; Ensure Search file closed
        PUSH    HL
        LD      HL,#5           ;   UZI link Fcn #
        PUSH    HL
-       RST     0x30            ;    Execute!
+       CALL    syscall         ;    Execute!
        POP     BC              ; Clean Stack
        POP     BC
        POP     BC
@@ -757,7 +759,7 @@ Fcn23:      CALL    CkSrch          ; Ensure Search file closed
        PUSH    HL
        LD      HL,#6           ;  UZI unlink Fcn #
        PUSH    HL
-       RST     0x30            ;   Execute!
+       CALL    syscall         ;   Execute!
        POP     BC              ; Clean Stack
        POP     BC
        JP      NC,Exit0        ;   exit w/0 if Ok
@@ -768,7 +770,7 @@ Fcn23:      CALL    CkSrch          ; Ensure Search file closed
        PUSH    HL
        LD      HL,#6           ;  UZI unlink Fcn #
        PUSH    HL
-       RST     0x30            ;   Execute!
+       CALL    syscall         ;   Execute!
        POP     BC              ; Clean Stack
        POP     BC
 
@@ -822,7 +824,7 @@ Fcn35:      CALL    CkSrch          ; Ensure Search file closed
        PUSH    HL              ;  dname
        LD      HL,#15          ;   UZI stat Fcn #
        PUSH    HL
-       RST     0x30            ;    Execute!
+       CALL    syscall         ;    Execute!
        POP     BC              ; Clean Stk
        POP     BC
        POP     BC
@@ -1002,7 +1004,7 @@ LSeek:    LD      BC,#0           ; Push 0 for absolute
        PUSH    HL
        LD      HL,#9           ; _lseek()
        PUSH    HL
-       RST     0x30            ; Syscall
+       CALL    syscall         ; Syscall
        POP     BC              ; Recover stack
        POP     BC
        POP     BC
@@ -1316,7 +1318,7 @@ Quit:
        LD      HL,#0           ; Exit Good Status
        PUSH    HL
        PUSH    HL              ;  UZI Fcn 0 (_exit)
-       RST     0x30            ;   Execute!
+       CALL    syscall         ;   Execute!
 Spin:  JR      Spin            ; Can't happen!
 
 ;.....
@@ -1345,7 +1347,7 @@ ConIn:    call    ConSt
        PUSH    HL
        LD      L,#7            ;    UZI Read Fcn
 ChrV0: PUSH    HL
-       RST     0x30            ;     Execute
+       CALL    syscall         ;     Execute
        POP     BC
        POP     BC
        POP     BC
@@ -1431,7 +1433,7 @@ RdWrt0:   PUSH    DE
        PUSH    HL
        LD      E,A             ;    Position R/W Fcn #
        PUSH    DE
-       RST     0x30            ;     Execute!
+       CALL    syscall         ;     Execute!
        POP     BC              ; Clear Stack
        POP     BC
        POP     BC
@@ -1456,7 +1458,7 @@ IoCtl:    PUSH    HL              ; &buf
        PUSH    DE
        LD      E,#29           ;    Fuzix ioctl Fcn #
        PUSH    DE
-       RST     0x30            ;     Execute!
+       CALL    syscall         ;     Execute!
        POP     BC              ; Clean Stack
        POP     BC
        POP     BC
@@ -1483,6 +1485,8 @@ dpb:      .dw     64              ; Dummy Disk Parameter Block
 
 ;----------------------- Data -----------------------
 
+syscall:
+       .ds     3
 ttTermios:
        .ds     20              ; Working TTY Port Settings
 ttTermios0: