Added new mode that relocates and runs programs to RAM.

prg_loader.s

@@ -0,0 +1,305 @@
+; Code originally by tIn/Newline, "creatively adjusted" by GGN.
+; Obviously in need of a cleanup!
+
+ULTRADEV        EQU 0				
+START_PAYLOAD   EQU 01
+start:
+
+
+                move.l  4(sp),a0         ; Obtain pointer to basepage
+                move.l  a0,d7            ; Save a copy (start of TPA)
+;                add.l #$100,a0           ; add basepage size (end of TPA)
+;                move.l  $c(a0),a1        ; Text size
+;                adda.l  $14(a0),a1      ; Data size
+;                adda.l  $18(a0),a1      ; BSS size
+;                adda.l  $1C(a0),a1      ; Add BSS size
+;                adda.l #$100,a1         ; Add Basepage size
+;                adda.l  #$200,a1         ; Add stack size
+
+                ;move.l %a1,%sp            ; Move your stack pointer to
+                                           ; your new stack.
+
+;                suba.l d7,a1             ; TPA size
+;                move.l a1,-(sp)
+                move.l #$100,-(sp)      ; new size - just the basepage if you don't mind
+                move.l d7,-(sp)         ; start of TPA
+                clr.w  -(sp)
+                move.w #$4a,-(sp)        ; Mshrink()
+                trap   #1
+                lea    12(sp),sp        ; Fix up stack
+
+;               ;malloc
+;               move.l  #payload-run,D0
+;               move.l  #-1,-(sp)       ; Return amount of largest chunk of RAM
+;               move.w  #72,-(sp)
+;               trap    #1              ; GEMDOS
+;               addq.l  #6,sp
+;
+;               move.l  D0,A0
+;               move.l  D0,A3
+;               lea     run,A1
+;               lea     payload,A2
+;.cl: 
+;               move.b  (A1)+,(A0)+
+;               cmp.l   A2,A1
+;               blt.s   .cl
+;
+;               jmp     (A3)
+
+run:
+
+                IFNE    START_PAYLOAD
+;from http://www.bitsavers.org/pdf/atari/ST/Atari_ST_GEM_Programming_1986/GEM_0042.pdf
+;TPA structure
+p_lowtpa        EQU $00 ;.l p_lowtpa -> base of TPA
+p_hitpa         EQU $04 ;.l p_hitpa -> end of TPA
+p_tbase         EQU $08 ;.l p_tbase base of text segment
+p_tlen          EQU $0c ;.l p_tlen size of text segment
+p_dbase         EQU $10 ;.l p_dbase base of data segment
+p_dlen          EQU $14 ;.l p_dlen size of data segment
+p_bbase         EQU $18 ;.l p_bbase base of BSS segment
+p_blen          EQU $1c ;.l p_blen size of BSS segment
+p_dta           EQU $20 ;.l p_dta Disk Transfer Address (DTA)
+p_parent        EQU $24 ;.l p_parent -> parent's basepage
+p_reserved      EQU $28 ;.l (reserved)  
+p_env           EQU $2c ;.l p_env -> enviroment string
+p_cmdlin        EQU $80 ;.l p_cmdlin commandline image
+;PRG file header
+prg_magic       EQU $00 ;.w Ox601A (magic number)
+prg_tlen        EQU $02 ;.l Size of text segment
+prg_dlen        EQU $06 ;.l Size of data segment
+prg_blen        EQU $0a ;.l Size of BSS segment
+prg_slen        EQU $0e ;.l Size of symbol table
+prg_reserved1   EQU $12 ;.l (reserved)
+prg_reserved2   EQU $16 ;.l (reserved)
+prg_reserved3   EQU $1a ;.l (reserved)
+prg_text        EQU $1e ;(start of text segment)
+
+                ;pea   0
+                ;pea   0
+                ;pea   null_long
+                ;move.w   #5,-(sp)       ; PE_BASEPAGE
+                ;move.w   #$4B,-(sp)
+                ;trap   #1
+                ;lea   16(sp),sp
+
+
+                move.l  #-1,-(sp)       ; Return amount of largest chunk of RAM
+                move.w  #72,-(sp)
+                trap    #1              ; GEMDOS
+                addq.l  #6,sp
+                ;@TODO handle not enough memory error
+                move.l  D0,-(sp)
+                move.w  #72,-(sp)
+                trap    #1              ; GEMDOS
+                addq.l  #6,sp
+                ;@TODO handle malloc error
+
+                move.l  D0,A0
+                lea     $100(A0),A0     ;reserve basepage
+;               lea     payload,A1
+                lea     'STRT',A1       ; will be filled later
+;               lea     eop,A2
+                lea     'END!',A2        ; will be filled later
+.cl: 
+                move.b  (A1)+,(A0)+
+                cmp.l   A2,A1
+                blt.s   .cl
+
+;                lea     pbasepage(PC),A1
+;                move.l  D0,(A1)
+                move.l  d0,d7           ;save a copy of basepage address
+                move.l  D0,A0
+                lea     $100(A0),A1     ;prg header
+
+                move.l  A0,p_lowtpa(A0)
+
+                lea     $1c(A1),A1
+                move.l  A1,p_tbase(A0)
+                move.l  prg_tlen+$100(A0),p_tlen(A0)
+                add.l   prg_tlen+$100(A0),A1
+
+                move.l  A1,p_dbase(A0)
+                move.l  prg_dlen+$100(A0),p_dlen(A0)
+                add.l   prg_dlen+$100(A0),A1
+
+                move.l  A1,p_bbase(A0)
+                move.l  prg_blen+$100(A0),p_blen(A0)
+                add.l   prg_blen+$100(A0),A1
+
+                add.l   prg_slen+$100(A0),A1
+
+                ;/from ultraDev (TOS1.02 by ultra, blame TOS1 "fix" to tIn)
+                lea     emptyEnvStr(PC),A2
+                move.l  A2,p_env(A0)
+                ;clr.l  p_cmdlin(A0)    ;is this correct? better use an empty commandline just to be sure
+                lea     emptyCommandline(PC),A2
+                move.l  A2,p_cmdlin(A0)
+
+                pea supervisor_code(pc)
+                move.w #$26,-(sp)
+                trap #14
+                addq.l #6,sp
+                bra past_supervisor_code
+
+supervisor_code:
+                move.l d7,a0
+
+                movea.l $04F2.w,a2      ;get Sysbase
+                movea.l 8(a2),a4        ;get rom start
+                move.l  $28(a4),a2      ;this is not present in TOS<1.02!
+;/---------------------
+;1MB TOS1.0 crash!!!    
+;   move.l  (a2),p_parent(A0)  ;<====== this does not work with TOS1.0, ROMSTART+$28 process pointer isn't present
+;   move.l  A0,(a2)         ;set act pd 
+;1MB TOS1.0 crash!!!    
+;\_____________________
+                ;START --------------------- TOS 1.0 workaround
+                ;check if this is TOS1.0 - unfortunately TOS1.0 does not know the first thing about cookies
+                tst.l   $5a0.w              ;cookie jar pointer
+                bne.s   .thisisnottos10     ;!=0 ==> TOS did set this, so we're definitively not on TOS 1.0
+                cmp.w   #$100,2(A4)
+                beq.s   .thisistos10
+                ;END ----------------------- TOS 1.0 workaround
+.thisisnottos10:
+                move.l  (a2),p_parent(A0)  ;<====== this does not work
+                move.l  A0,(a2)         ;set act pd 
+                bra.s   .no1
+.thisistos10:
+                ;START --------------------- TOS 1.0 workaround
+                ;taken from BUGABOOs "init_all"
+                lea     $602C.w,A2                  ;act_pd (vor dem Blitter-TOS)
+                move.w  $1C(A4),D0                  ;os_conf holen
+                lsr.w   #1,D0                       ;PAL/NTSC-Mode ignorieren
+                subq.w  #4,D0                       ;Spanisches TOS 1.0?
+                bne.s   .noESTOS10                  ;Nein! =>
+                lea     $873C-$602C(A2),A2          ;act_pd des spanischen TOS 1.0
+.noESTOS10:
+                move.l  A0,(A2)
+                ;END ----------------------- TOS 1.0 workaround
+.no1:
+                ;\from ultraDev
+
+
+ ;@TODO: better stack handling
+;                move.l  $44e.w,SP
+;                move.l  SP,p_hitpa(A0)  ;SSP
+;                lea     -10000(SP),A3   ;USP
+;                move    #$700,sr
+
+                rts
+
+past_supervisor_code:
+;                move.l  A3,SP
+
+
+                move.l d7,a0
+
+                ;/from ultraDev
+                move.l  A0,-(a7)    ;put code page to stack
+                clr.l   -(a7)       ;clear something ;)
+                ;\from ultraDev
+
+                ;move.l  pbasepage(PC),A0
+                move.l  d7,A0
+                lea     $100(A0),A0
+                move.l  A0,A1
+                bsr     kernel_relocate
+
+                lea     0.w,A0 ;apparently we need to set this to zero? why? TPA address _should_ work?
+                ;move.l  pbasepage(PC),A3
+                move.l  d7,A3
+                jmp     $100+$1c(A3)
+;pbasepage:      DC.L    0
+;=================================================
+;                                       PRG-Header
+kernel_prg_text_len:   EQU     2
+kernel_prg_data_len:   EQU     2+4
+kernel_prg_bss_len:    EQU     2+4+4
+kernel_prg_symbol_len: EQU     2+4+4+4
+kernel_prg_flags:      EQU     2+4+4+4+4+4 
+kernel_prg_relocflag:  EQU     2+4+4+4+4+4+4 
+;=================================================
+;                                    PRG-Relocator
+;=================================================
+;A0=>Start PRG
+;A1=>where's the PRG actually _started_?
+;out: A1=>Start BSS
+kernel_relocate:
+                tst.w   kernel_prg_relocflag(A0)
+                bne.s   .k_noreloc
+                lea     $1c(A1),A3      ;address to relocate to
+                move.l  A3,D2
+                lea     $1c(A0),A3      
+                move.l  A3,A2
+                adda.l  kernel_prg_text_len(A0),A2
+                adda.l  kernel_prg_data_len(A0),A2
+                move.l  kernel_prg_bss_len(A0),D3
+                move.l  A2,A1
+                adda.l  kernel_prg_symbol_len(A0),A2
+                move.l  (A2)+,D0
+                beq.s   .k_noreloc
+                moveq   #0,D1
+.k_relocloop:   add.l   D2,0(A3,D0.l)
+.k_relocloop2:  move.b  (A2)+,D1
+                beq.s   .k_noreloc
+                cmp.b   #1,D1
+                beq.s   .k_reloclong
+                add.l   D1,D0
+                bra.s   .k_relocloop
+.k_reloclong:   add.l   #254,D0
+                bra.s   .k_relocloop2
+.k_noreloc:   
+                rts             
+                ELSE
+w:              bra.s   w               
+                ENDC
+
+;from ultraDev
+emptyEnvStr: dc.b   "PATH=",0
+    dc.b    "A:\",0,0
+emptyCommandline: dc.b 0    
+    even
+
+;null_long:  dc.l 0
+
+;clearScreen:
+;                pea     cls(PC)
+;                move.w  #9,-(SP)
+;                trap    #1
+;                addq.l  #6,SP
+;                rts
+;;A0: text
+;;D0: X
+;;D1: Y
+;printText:
+;               lea     gotox(PC),A1
+;               add.w   #32,D0
+;               add.w   #32,D1
+;               move.b  D0,(A1)
+;               move.b  D1,gotoy-gotox(A1)
+;
+;               pea     goto-gotox(A1)  ;move cursor
+;               move.w  #9,-(SP)
+;               trap    #1
+;               addq.l  #6,SP
+;
+;               pea     (A0)            ;print text
+;               move.w  #9,-(SP)
+;               trap    #1
+;               addq.l  #6,SP
+;               rts
+;cls:           DC.B 27,'E',0               
+;goto:          DC.B 27,'Y'
+;gotoy:          DC.B 0
+;gotox:             DC.B 0
+;               DC.B 0
+;               EVEN
+
+;               include "hwinfo.s"
+;               EVEN
+payload:                
+                IFNE START_PAYLOAD
+                ;incbin "ikaifill.tos"
+                ENDC
+eop:

prg_loader_build.bat

@@ -0,0 +1 @@
+vasm -quiet -Fbin -o prg_loader.bin prg_loader.s

readme.md

@@ -14,8 +14,9 @@ where:
 
 - *-s* is optional and allows creation of STEem Engine compatible carts
 - *-d* enables creation of diagnostic cartridges (only one program allowed, which will relocate to $fa0004)
-- *-bX* allows setting the BSS address to an address other than the default ($20000)
-- *-fY* allows setint the INIT flag. y can be
+- *-c* to switch to the classic way of adding the application to the ROM
+- *-bX* allows setting the BSS address to an address other than the default ($only when -c is active, default: $20000)
+- *-fY* allows seting the INIT flag. y can be
   - 0       Execute prior to display memory and interrupt vector initialization
   - 1       Execute just before GEMDOS is initialized
   - 3       Execute prior to boot disk
@@ -25,23 +26,24 @@ where:
 - *image_filename* is the filename of the cart image
 - *list of programs to add with optional -b and -f* is a list of ST PRG programs to add to the image, optionally postfixed by a *-b* and/or *-f* to set the parameters for the current file only
 
-More on defaults: The default value for *-b* is $20000, and the default value for *-f* is nothing. Passing *-b* and/or *-f* at the start of the parameter list will override the default values. Passing *-b* and/or *-f* after each program in the list, will override the defaults for that file only.
+More on defaults: The default value for *-b* is $20000, and the default value for *-f* is 0. Passing *-b* and/or *-f* at the start of the parameter list will override the default values. Passing *-b* and/or *-f* after each program in the list, will override the defaults for that file only.
 
-How it works (briefly)
+Two modes of operation
 ----------------------
 
-Current (and only) mode of operation is that the program gets the PRG (or PRGs), relocates TEXT and DATA sections to ROM space and BSS to RAM at a hardcoded address, and hopes for the best.
+Until the second release there was a single mode of operation (explained below).
 
-This is not the best (or robust) idea in the world, but at least it made sense when the program was conceptualised. See below for ideas for further development.
+The current default mode is to add a TOS PRG file with a small stub loader included which will copy the actual program from ROM to RAM, try to set up the system as well as it can, and then execute the program from RAM.
 
-Caveats (boy, here we go)
--------------------------
+The old mode adds the program to ROM and relocates it to run from there, with the BSS start address set in RAM by the user (or default value is used). This mode works for simple applications, but there will be many problems down the road for non properly written applications for this mode (i.e. pretty much all of them).
+
+Caveats
+-------
 
 - Only use single file PRG programs. Programs that try to load external files will not work
 - TODO: Some sanity checks are performed, but the program is far from bullet proof
-- TODO: The BSS start address has to be supplied by user (or accept the default value of $20000). Unfotunately it doesn't seem possible to do this automatically. If anyone has an idea on how to do this, happy to discuss!
-- On BSS: programs that access the BSS using PC relative code will most likely fail
-- TODO: Date and Time are still set to bogus vaules
+- TODO: Date and Time are still set to bogus values
+- On BSS, for "old" mode: programs that access the BSS using PC relative code will most likely fail
 
 Building
 --------
@@ -59,3 +61,4 @@ Thank yous
 ----------
 
 Diego Parrilla for supplying the Github actions to automatically build binaries for all platforms, and some other fixes in the code.
+tIn/Newline for the original stub loader source code.