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Added files to the pet library that support the overlay demo sample program. 

cbm_load() is needed because the Pet/CBM Kernals don't have a LOAD function that can be used by machine code programs.
This commit is contained in:
Greg King 2020-10-15 21:22:04 -04:00
parent e682f7c8c3
commit a25b28a972
2 changed files with 141 additions and 0 deletions
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82
cfg/pet-overlay.cfg Normal file
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FEATURES {
STARTADDRESS: default = $0401;
}
SYMBOLS {
__LOADADDR__: type = import;
__EXEHDR__: type = import;
__OVERLAYADDR__: type = import;
__STACKSIZE__: type = weak, value = $0800; # 2K stack
__OVERLAYSIZE__: type = weak, value = $0800; # 2K overlay
__HIMEM__: type = weak, value = $8000;
__OVERLAYSTART__: type = export, value = __HIMEM__ - __STACKSIZE__ - __OVERLAYSIZE__;
}
MEMORY {
ZP: file = "", define = yes, start = $0055, size = $001A;
LOADADDR: file = %O, start = %S - 2, size = $0002;
HEADER: file = %O, define = yes, start = %S, size = $000D;
MAIN: file = %O, define = yes, start = __HEADER_LAST__, size = __OVERLAYSTART__ - __HEADER_LAST__;
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 = MAIN, type = ro;
LOWCODE: load = MAIN, type = ro, optional = yes;
CODE: load = MAIN, type = ro;
ONCE: load = MAIN, type = ro, optional = yes;
RODATA: load = MAIN, type = ro;
DATA: load = MAIN, type = rw;
INIT: load = MAIN, type = bss;
BSS: load = MAIN, type = bss, define = yes;
OVL1ADDR: load = OVL1ADDR, type = ro;
OVERLAY1: load = OVL1, type = ro, define = yes, optional = yes;
OVL2ADDR: load = OVL2ADDR, type = ro;
OVERLAY2: load = OVL2, type = ro, define = yes, optional = yes;
OVL3ADDR: load = OVL3ADDR, type = ro;
OVERLAY3: load = OVL3, type = ro, define = yes, optional = yes;
OVL4ADDR: load = OVL4ADDR, type = ro;
OVERLAY4: load = OVL4, type = ro, define = yes, optional = yes;
OVL5ADDR: load = OVL5ADDR, type = ro;
OVERLAY5: load = OVL5, type = ro, define = yes, optional = yes;
OVL6ADDR: load = OVL6ADDR, type = ro;
OVERLAY6: load = OVL6, type = ro, define = yes, optional = yes;
OVL7ADDR: load = OVL7ADDR, type = ro;
OVERLAY7: load = OVL7, type = ro, define = yes, optional = yes;
OVL8ADDR: load = OVL8ADDR, type = ro;
OVERLAY8: load = OVL8, type = ro, define = yes, optional = yes;
OVL9ADDR: load = OVL9ADDR, type = ro;
OVERLAY9: load = OVL9, type = ro, define = yes, optional = yes;
}
FEATURES {
CONDES: type = constructor,
label = __CONSTRUCTOR_TABLE__,
count = __CONSTRUCTOR_COUNT__,
segment = ONCE;
CONDES: type = destructor,
label = __DESTRUCTOR_TABLE__,
count = __DESTRUCTOR_COUNT__,
segment = RODATA;
CONDES: type = interruptor,
label = __INTERRUPTOR_TABLE__,
count = __INTERRUPTOR_COUNT__,
segment = RODATA,
import = __CALLIRQ__;
}

59
libsrc/pet/cbm_load.c Normal file
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/*
** 2020-10-15, Greg King
**
** unsigned int __fastcall__ cbm_load (const char* name,
** unsigned char device,
** void* data);
*/
#include <cbm.h>
#include <limits.h>
/* Loads file "name" from the given device to the given address, or to the load
** address of the file if "data" is the null pointer (like load"name",8,1
** in BASIC).
** Returns the number of bytes that were loaded if loading was successful;
** otherwise 0; "_oserror" contains an error-code, then.
*/
unsigned int __fastcall__ cbm_load (const char* name, unsigned char device, void* data)
{
void* load;
int length;
unsigned int size = 0;
if (cbm_open (1, device, CBM_READ, name) != 0) {
/* Can't load from a file that can't be openned. */
return 0;
}
/* Get the file's load address. */
if (cbm_read (1, &load, sizeof load) != sizeof load) {
/* Either the file wasn't found, or it was too short. (Note:
** the computer openned a file even if the drive couldn't open one.)
*/
cbm_close (1);
return 0;
}
/* If "data" doesn't hold an address, then use the file's address. */
if (data == (void*)0x0000) {
data = load;
}
/* Pull the file into RAM. [Note that, if cbm_read() grabbed more
** than 32767 bytes at a time, then its result would look negative,
** which would cancel the load.]
*/
do {
size += (length = cbm_read (1, data, INT_MAX));
data = (unsigned char*)data + length;
} while (length == INT_MAX && cbm_k_readst() == 0);
cbm_close (1);
/* "length" is -1 if there was an error. */
if (length < 0) {
size = 0;
}
return size;
}