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Merge pull request #215 from greg-king5/c64-init

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Save space by using the apple2 target's INIT overlay scheme on the c64 target.
This commit is contained in:
Oliver Schmidt 2015-10-14 10:43:11 +02:00
commit 8f67dd5cc7
5 changed files with 191 additions and 107 deletions
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2
asminc/c64.inc
View file

@ -24,6 +24,7 @@ SCREEN_PTR := $D1 ; Pointer to current char in text screen
CURS_X := $D3 ; Cursor column
CURS_Y := $D6 ; Cursor row
CRAM_PTR := $F3 ; Pointer to current char in color RAM
FREKZP := $FB ; Five unused bytes
BASIC_BUF := $200 ; Location of command-line
BASIC_BUF_LEN = 89 ; Maximum length of command-line
@ -212,4 +213,3 @@ CASSMOT = $20 ; Cassette motor on
TP_FAST = $80 ; Switch Rossmoeller TurboProcess to fast mode
RAMONLY = $F8 ; (~(LORAM | HIRAM | IOEN)) & $FF

54
cfg/c64-overlay.cfg
View file

@ -1,46 +1,52 @@
FEATURES {
STARTADDRESS: default = $0801;
}
SYMBOLS {
__LOADADDR__: type = import;
__EXEHDR__: type = import;
__OVERLAYADDR__: type = import;
__STACKSIZE__: type = weak, value = $0800; # 2k stack
__OVERLAYSIZE__: type = weak, value = $1000; # 4k overlay
__HIMEM__: type = weak, value = $D000;
__OVERLAYSTART__: type = export, value = __HIMEM__ - __OVERLAYSIZE__;
}
MEMORY {
ZP: file = "", define = yes, start = $0002, size = $001A;
LOADADDR: file = %O, start = $07FF, size = $0002;
HEADER: file = %O, start = $0801, size = $000C;
RAM: file = %O, define = yes, start = $080D, size = $C7F3 - __OVERLAYSIZE__ - __STACKSIZE__;
OVL1ADDR: file = "%O.1", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL1: file = "%O.1", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
OVL2ADDR: file = "%O.2", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL2: file = "%O.2", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
OVL3ADDR: file = "%O.3", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL3: file = "%O.3", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
OVL4ADDR: file = "%O.4", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL4: file = "%O.4", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
OVL5ADDR: file = "%O.5", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL5: file = "%O.5", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
OVL6ADDR: file = "%O.6", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL6: file = "%O.6", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
OVL7ADDR: file = "%O.7", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL7: file = "%O.7", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
OVL8ADDR: file = "%O.8", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL8: file = "%O.8", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
OVL9ADDR: file = "%O.9", start = $CFFE - __OVERLAYSIZE__, size = $0002;
OVL9: file = "%O.9", start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
LOADADDR: file = %O, start = %S - 2, size = $0002;
HEADER: file = %O, define = yes, start = %S, size = $000D;
RAM: file = %O, define = yes, start = __HEADER_LAST__, size = __OVERLAYSTART__ - __STACKSIZE__ - __HEADER_LAST__;
MOVE: file = %O, start = __ZPSAVE_LOAD__, size = __HIMEM__ - __INIT_RUN__;
OVL1ADDR: file = "%O.1", start = __OVERLAYSTART__ - 2, size = $0002;
OVL1: file = "%O.1", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL2ADDR: file = "%O.2", start = __OVERLAYSTART__ - 2, size = $0002;
OVL2: file = "%O.2", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL3ADDR: file = "%O.3", start = __OVERLAYSTART__ - 2, size = $0002;
OVL3: file = "%O.3", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL4ADDR: file = "%O.4", start = __OVERLAYSTART__ - 2, size = $0002;
OVL4: file = "%O.4", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL5ADDR: file = "%O.5", start = __OVERLAYSTART__ - 2, size = $0002;
OVL5: file = "%O.5", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL6ADDR: file = "%O.6", start = __OVERLAYSTART__ - 2, size = $0002;
OVL6: file = "%O.6", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL7ADDR: file = "%O.7", start = __OVERLAYSTART__ - 2, size = $0002;
OVL7: file = "%O.7", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL8ADDR: file = "%O.8", start = __OVERLAYSTART__ - 2, size = $0002;
OVL8: file = "%O.8", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
OVL9ADDR: file = "%O.9", start = __OVERLAYSTART__ - 2, size = $0002;
OVL9: file = "%O.9", start = __OVERLAYSTART__, size = __OVERLAYSIZE__;
}
SEGMENTS {
ZEROPAGE: load = ZP, type = zp;
LOADADDR: load = LOADADDR, type = ro;
EXEHDR: load = HEADER, type = ro;
STARTUP: load = RAM, type = ro;
LOWCODE: load = RAM, type = ro, optional = yes;
INIT: load = RAM, type = ro, define = yes, optional = yes;
CODE: load = RAM, type = ro;
RODATA: load = RAM, type = ro;
DATA: load = RAM, type = rw;
ZPSAVE: load = RAM, type = bss;
ZPSAVE: load = RAM, type = bss, define = yes;
BSS: load = RAM, type = bss, define = yes;
ZEROPAGE: load = ZP, type = zp;
INIT: load = MOVE, run = RAM, type = ro, define = yes;
OVL1ADDR: load = OVL1ADDR, type = ro;
OVERLAY1: load = OVL1, type = ro, define = yes, optional = yes;
OVL2ADDR: load = OVL2ADDR, type = ro;

17
cfg/c64.cfg
View file

@ -1,26 +1,31 @@
FEATURES {
STARTADDRESS: default = $0801;
}
SYMBOLS {
__LOADADDR__: type = import;
__EXEHDR__: type = import;
__STACKSIZE__: type = weak, value = $0800; # 2k stack
__HIMEM__: type = weak, value = $D000;
}
MEMORY {
ZP: file = "", define = yes, start = $0002, size = $001A;
LOADADDR: file = %O, start = $07FF, size = $0002;
HEADER: file = %O, start = $0801, size = $000C;
RAM: file = %O, define = yes, start = $080D, size = $C7F3 - __STACKSIZE__;
LOADADDR: file = %O, start = %S - 2, size = $0002;
HEADER: file = %O, define = yes, start = %S, size = $000D;
RAM: file = %O, define = yes, start = __HEADER_LAST__, size = __HIMEM__ - __STACKSIZE__ - __HEADER_LAST__;
MOVE: file = %O, start = __ZPSAVE_LOAD__, size = __HIMEM__ - __INIT_RUN__;
}
SEGMENTS {
ZEROPAGE: load = ZP, type = zp;
LOADADDR: load = LOADADDR, type = ro;
EXEHDR: load = HEADER, type = ro;
STARTUP: load = RAM, type = ro;
LOWCODE: load = RAM, type = ro, optional = yes;
INIT: load = RAM, type = ro, define = yes, optional = yes;
CODE: load = RAM, type = ro;
RODATA: load = RAM, type = ro;
DATA: load = RAM, type = rw;
ZPSAVE: load = RAM, type = bss;
ZPSAVE: load = RAM, type = bss, define = yes;
BSS: load = RAM, type = bss, define = yes;
ZEROPAGE: load = ZP, type = zp;
INIT: load = MOVE, run = RAM, type = ro, define = yes;
}
FEATURES {
CONDES: type = constructor,

98
libsrc/c64/crt0.s
View file

@ -4,12 +4,12 @@
.export _exit
.export __STARTUP__ : absolute = 1 ; Mark as startup
.import initlib, donelib
.import zerobss
.import callmain
.import RESTOR, BSOUT, CLRCH
.import moveinit, zerobss, callmain
.import BSOUT
.import __RAM_START__, __RAM_SIZE__ ; Linker generated
.import __STACKSIZE__ ; Linker generated
.import __STACKSIZE__ ; from configure file
.importzp ST
.include "zeropage.inc"
@ -23,14 +23,6 @@
Start:
; Save the zero-page locations that we need.
ldx #zpspace-1
L1: lda sp,x
sta zpsave,x
dex
bpl L1
; Switch to the second charset.
lda #14
@ -39,35 +31,30 @@ L1: lda sp,x
; Switch off the BASIC ROM.
lda $01
pha ; Remember the value
sta mmusave ; Save the memory configuration
and #$F8
ora #$06 ; Enable Kernal+I/O, disable BASIC
sta $01
; Clear the BSS data.
jsr zerobss
; Save some system settings; and, set up the stack.
pla
sta mmusave ; Save the memory configuration
tsx
stx spsave ; Save the system stack ptr
lda #<(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)
sta sp
lda #>(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)
sta sp+1 ; Set argument stack ptr
; Allow some re-entrancy by skipping the next task if it already was done.
; This sometimes can let us rerun the program without reloading it.
; Call the module constructors.
ldx move_init
beq L0
jsr initlib
; Move the INIT segment from where it was loaded (over ZPSAVE and BSS)
; into where it must be run (in the heap).
; Push the command-line arguments; and, call main().
jsr moveinit
dec move_init ; set to false
jsr callmain
; Save space by putting the rest of the start-up code in the INIT segment,
; which can be re-used by the heap and the C stack.
L0: jsr initstart
; Back from main() [this is also the exit() entry]. Run the module destructors.
@ -98,14 +85,55 @@ L2: lda zpsave,x
rts
; ------------------------------------------------------------------------
.segment "INIT"
initstart:
; Save the zero-page locations that we need.
ldx #zpspace-1
L1: lda sp,x
sta zpsave,x
dex
bpl L1
; Clear the BSS data.
jsr zerobss
; Set up the stack.
lda #<(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)
ldx #>(__RAM_START__ + __RAM_SIZE__ + __STACKSIZE__)
sta sp
stx sp+1 ; Set argument stack ptr
; Call the module constructors.
jsr initlib
; Push the command-line arguments; and, call main().
jmp callmain
; ------------------------------------------------------------------------
; Data
.data
; These two variables were moved out of the BSS segment, and into DATA, because
; we need to use them before INIT is moved off of BSS, and before BSS is zeroed.
mmusave:.res 1
spsave: .res 1
move_init:
.byte 1
.segment "ZPSAVE"
zpsave: .res zpspace
.bss
spsave: .res 1
mmusave:.res 1

45
libsrc/common/moveinit.s Normal file
View file

@ -0,0 +1,45 @@
;
; 2015-10-07, Greg King
;
.export moveinit
.import __INIT_LOAD__, __INIT_RUN__, __INIT_SIZE__ ; Linker-generated
.macpack cpu
.macpack generic
; Put this in the DATA segment because it is self-modifying code.
.data
; Move the INIT segment from where it was loaded (over the bss segments)
; into where it must be run (in the heap). The two areas might overlap; and,
; the segment is moved upwards. Therefore, this code starts at the highest
; address, and decrements to the lowest address. The low bytes of the starting
; pointers are not sums. The high bytes are sums; but, they do not include the
; carry. Both the low-byte sums and the carries will be done when the pointers
; are indexed by the .Y register.
moveinit:
; First, move the last, partial page.
; Then, move all of the full pages.
ldy #<__INIT_SIZE__ ; size of partial page
ldx #>__INIT_SIZE__ + (<__INIT_SIZE__ <> 0) ; number of pages, including partial
L1: dey
init_load:
lda __INIT_LOAD__ + (__INIT_SIZE__ & $FF00) - $0100 * (<__INIT_SIZE__ = 0),y
init_run:
sta __INIT_RUN__ + (__INIT_SIZE__ & $FF00) - $0100 * (<__INIT_SIZE__ = 0),y
tya
bnz L1 ; page not finished
dec init_load+2
dec init_run+2
dex
bnz L1 ; move next page
rts