6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2024-11-16 02:10:52 +00:00
Code Issues Projects Releases Wiki Activity
14956f3b15
cc65/libsrc/sim6502/crt0.s

34 lines
913 B
ArmAsm
Raw Normal View History

Added 'sim6502' and 'sim65C02' targets. The targets allow to run cc65 programs in the sim65 exection einvironment. As there are no "real" i/o facilities there's no need for header files. Paravirtualized entry points are mapped to $FFF0 ff. There's a large cc65 progam area from $0200-$FFEF. The binary format includes a one-byte header indicating the required execution environment: The value 0 means 6502 and the value 1 means 65C02. The load adress for the binary is fixed to $0200. Note: Running sim65C02 programs currently doesn't work bcause sim65 doesn't actually implement 65C02 opcodes.
2013-05-20 18:35:42 +00:00
;
; Oliver Schmidt, 2013-05-16
;
; Startup code for cc65 (sim6502 version)
;
.export _exit
Renamed program start label.
2019-05-29 22:06:31 +00:00
.export startup
Added 'sim6502' and 'sim65C02' targets. The targets allow to run cc65 programs in the sim65 exection einvironment. As there are no "real" i/o facilities there's no need for header files. Paravirtualized entry points are mapped to $FFF0 ff. There's a large cc65 progam area from $0200-$FFEF. The binary format includes a one-byte header indicating the required execution environment: The value 0 means 6502 and the value 1 means 65C02. The load adress for the binary is fixed to $0200. Note: Running sim65C02 programs currently doesn't work bcause sim65 doesn't actually implement 65C02 opcodes.
2013-05-20 18:35:42 +00:00
.export __STARTUP__ : absolute = 1 ; Mark as startup
.import zerobss, callmain
.import initlib, donelib
.import exit
Renamed RAM to MAIN for all disk based targets. The name RAM doesn't make much sense in general for a memeory area because i.e. the zero page is for sure RAM but is not part of the memory area named RAM. For disk based targets it makes sense to put the disk file more into focus and here MAIN means the main part of the file - in contrast to some header. Only for ROM based targets the name RAM is kept as it makes sense to focus on the difference between RAM and ROM.
2016-03-07 00:28:55 +00:00
.import __MAIN_START__, __MAIN_SIZE__ ; Linker generated
Added 'sim6502' and 'sim65C02' targets. The targets allow to run cc65 programs in the sim65 exection einvironment. As there are no "real" i/o facilities there's no need for header files. Paravirtualized entry points are mapped to $FFF0 ff. There's a large cc65 progam area from $0200-$FFEF. The binary format includes a one-byte header indicating the required execution environment: The value 0 means 6502 and the value 1 means 65C02. The load adress for the binary is fixed to $0200. Note: Running sim65C02 programs currently doesn't work bcause sim65 doesn't actually implement 65C02 opcodes.
2013-05-20 18:35:42 +00:00
.import __STACKSIZE__ ; Linker generated
.include "zeropage.inc"
.segment "STARTUP"
Renamed program start label.
2019-05-29 22:06:31 +00:00
startup:cld
Added 'sim6502' and 'sim65C02' targets. The targets allow to run cc65 programs in the sim65 exection einvironment. As there are no "real" i/o facilities there's no need for header files. Paravirtualized entry points are mapped to $FFF0 ff. There's a large cc65 progam area from $0200-$FFEF. The binary format includes a one-byte header indicating the required execution environment: The value 0 means 6502 and the value 1 means 65C02. The load adress for the binary is fixed to $0200. Note: Running sim65C02 programs currently doesn't work bcause sim65 doesn't actually implement 65C02 opcodes.
2013-05-20 18:35:42 +00:00
ldx #$FF
txs
Renamed RAM to MAIN for all disk based targets. The name RAM doesn't make much sense in general for a memeory area because i.e. the zero page is for sure RAM but is not part of the memory area named RAM. For disk based targets it makes sense to put the disk file more into focus and here MAIN means the main part of the file - in contrast to some header. Only for ROM based targets the name RAM is kept as it makes sense to focus on the difference between RAM and ROM.
2016-03-07 00:28:55 +00:00
lda #<(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)
ldx #>(__MAIN_START__ + __MAIN_SIZE__ + __STACKSIZE__)
Added 'sim6502' and 'sim65C02' targets. The targets allow to run cc65 programs in the sim65 exection einvironment. As there are no "real" i/o facilities there's no need for header files. Paravirtualized entry points are mapped to $FFF0 ff. There's a large cc65 progam area from $0200-$FFEF. The binary format includes a one-byte header indicating the required execution environment: The value 0 means 6502 and the value 1 means 65C02. The load adress for the binary is fixed to $0200. Note: Running sim65C02 programs currently doesn't work bcause sim65 doesn't actually implement 65C02 opcodes.
2013-05-20 18:35:42 +00:00
sta sp
stx sp+1
jsr zerobss
jsr initlib
jsr callmain
_exit: pha
jsr donelib
pla
The paravirtualization hooks are called for JMP too so there's no need for JSR.
2013-05-24 16:25:16 +00:00
jmp exit
Reference in New Issue Copy Permalink