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Added a Contiki version of the CBM exec() system file; it uses PFS instead of POSIX.

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It reduces the webbrowsers' size by 735 bytes.
This commit is contained in:
Oliver Schmidt 2016-03-28 20:03:47 +02:00
parent b287351d99
commit 7a5249b066
4 changed files with 280 additions and 2 deletions
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2
platform/c128/Makefile.c128
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@ -31,7 +31,7 @@
# Author: Oliver Schmidt <ol.sc@web.de> # Author: Oliver Schmidt <ol.sc@web.de>
# #
CONTIKI_TARGET_SOURCEFILES += lseek.c pfs.S pfs_remove.S pfs_seek.S pfs_write.S CONTIKI_TARGET_SOURCEFILES += exec.c lseek.c pfs.S pfs_remove.S pfs_seek.S pfs_write.S
CONTIKI_CPU = $(CONTIKI)/cpu/6502 CONTIKI_CPU = $(CONTIKI)/cpu/6502
include $(CONTIKI_CPU)/Makefile.6502 include $(CONTIKI_CPU)/Makefile.6502

139
platform/c128/lib/exec.c Normal file
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/*
** Program-chaining function for Commodore platforms.
**
** This copy of the cc65 system library function makes smaller code by using
** Contiki's Personal File System (instead of POSIX) functions.
**
** 2016-03-16, Greg King
**
** This function exploits the program-chaining feature in CBM BASIC's ROM.
**
** CC65's CBM programs have a BASIC program stub. We start those programs by
** RUNning that stub; it SYSes to the Machine Language code. Normally, after
** the ML code exits, the BASIC ROM continues running the stub. But, it has
** no more statements; so, the program stops.
**
** This function puts the desired program's name and device number into a LOAD
** statement. Then, it points BASIC to that statement, so that the ROM will run
** that statement after this program quits. The ROM will load the next program,
** and will execute it (because the LOAD will be seen in a running program).
*/
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <device.h>
#include "cfs.h"
/* The struct below is a line of BASIC code. It sits in the LOWCODE segment
** to make sure that it won't be hidden by a ROM when BASIC is re-enabled.
** The line is:
** 0 CLR:LOAD""+"" ,01
** After this function has written into the line, it might look like this:
** 0 CLR:LOAD""+"program name" ,08
**
** When BASIC's LOAD command asks the Kernal to load a file, it gives the
** Kernal a pointer to a file-name string. CC65's CBM programs use that
** pointer to give a copy of the program's name to main()'s argv[0] parameter.
** But, when BASIC uses a string literal that is in a program, it points
** directly to that literal -- in the models that don't use banked RAM
** (Pet/CBM, VIC-20, and 64). The literal is overwritten by the next program
** that is loaded. So, argv[0] would point to machine code. String operations
** create a new result string -- even when that operation changes nothing. The
** result is put in the string space at the top of BASIC's memory. So, the ""+
** in this BASIC line guarantees that argv[0] will get a name from a safe place.
*/
#pragma data-name(push, "LOWCODE")
static struct line {
const char end_of_line; /* fake previous line */
const struct line* const next;
const unsigned line_num;
const char CLR_token, colon, LOAD_token, quotes[2], add_token, quote;
char name[21];
const char comma;
char unit[3];
} basic = {
'\0', &basic + 1, /* high byte of link must be non-zero */
0, 0x9C, ':', 0x93, "\"\"", 0xAA, '\"',
"\" ", /* format: "123:1234567890123456\"" */
',', "01"
};
#pragma data-name(pop)
/* These values are platform-specific. */
extern const void* vartab; /* points to BASIC program variables */
#pragma zpsym("vartab")
extern const void* memsize; /* points to top of BASIC RAM */
#pragma zpsym("memsize")
extern const struct line* txtptr; /* points to BASIC code */
#pragma zpsym("txtptr")
extern char basbuf[]; /* BASIC's input buffer */
extern void basbuf_len[];
#pragma zpsym("basbuf_len")
int __fastcall__
exec(const char *progname, const char *cmdline)
{
static int fd;
static unsigned char dv, n;
/* Exclude devices that can't load files. */
/* (Use hand optimization, to make smaller code.) */
dv = getcurrentdevice();
if(dv < 8 && __AX__ != 1 || __AX__ > 30) {
return _mappederrno(9); /* illegal device number */
}
utoa(dv, basic.unit, 10);
/* Tape files can be openned only once; skip this test for the Datasette. */
if(dv != 1) {
/* Don't try to run a program that can't be found. */
fd = cfs_open(progname, CFS_READ);
if(fd < 0) {
return -1;
}
cfs_close(fd);
}
n = 0;
do {
if((basic.name[n] = progname[n]) == '\0') {
break;
}
} while(++n < 20); /* truncate long names */
basic.name[n] = '\"';
/* This next part isn't needed by machines that put
** BASIC source and variables in different RAM banks.
*/
#if !defined(__C128__)
/* cc65 program loads might extend beyond the end of the RAM that is allowed
** for BASIC. Then, the LOAD statement would complain that it is "out of
** memory". Some pointers that say where to put BASIC program variables
** must be changed, so that we do not get that error. One pointer is
** changed here; a BASIC CLR statement changes the others. Some space is
** needed for the file-name string. Subtracting an entire RAM page allows
** better optimization of this expression.
*/
vartab = (char*)memsize - 0x0100;
#endif
/* Build the next program's argument list. */
basbuf[0] = 0x8F; /* REM token */
basbuf[1] = '\0';
if(cmdline != NULL) {
strncat(basbuf, cmdline, (size_t)basbuf_len - 2);
}
/* Tell the ROM where to find that BASIC program. */
txtptr = &basic;
/* (The return code, in ST [status], will be destroyed by LOAD.
** So, don't bother to set it here.)
*/
exit(__AX__);
}

2
platform/c64/Makefile.c64
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@ -31,7 +31,7 @@
# Author: Oliver Schmidt <ol.sc@web.de> # Author: Oliver Schmidt <ol.sc@web.de>
# #
CONTIKI_TARGET_SOURCEFILES += lseek.c pfs.S pfs_remove.S pfs_seek.S pfs_write.S CONTIKI_TARGET_SOURCEFILES += exec.c lseek.c pfs.S pfs_remove.S pfs_seek.S pfs_write.S
CONTIKI_CPU = $(CONTIKI)/cpu/6502 CONTIKI_CPU = $(CONTIKI)/cpu/6502
include $(CONTIKI_CPU)/Makefile.6502 include $(CONTIKI_CPU)/Makefile.6502

139
platform/c64/lib/exec.c Normal file
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@ -0,0 +1,139 @@
/*
** Program-chaining function for Commodore platforms.
**
** This copy of the cc65 system library function makes smaller code by using
** Contiki's Personal File System (instead of POSIX) functions.
**
** 2016-03-16, Greg King
**
** This function exploits the program-chaining feature in CBM BASIC's ROM.
**
** CC65's CBM programs have a BASIC program stub. We start those programs by
** RUNning that stub; it SYSes to the Machine Language code. Normally, after
** the ML code exits, the BASIC ROM continues running the stub. But, it has
** no more statements; so, the program stops.
**
** This function puts the desired program's name and device number into a LOAD
** statement. Then, it points BASIC to that statement, so that the ROM will run
** that statement after this program quits. The ROM will load the next program,
** and will execute it (because the LOAD will be seen in a running program).
*/
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <device.h>
#include "cfs.h"
/* The struct below is a line of BASIC code. It sits in the LOWCODE segment
** to make sure that it won't be hidden by a ROM when BASIC is re-enabled.
** The line is:
** 0 CLR:LOAD""+"" ,01
** After this function has written into the line, it might look like this:
** 0 CLR:LOAD""+"program name" ,08
**
** When BASIC's LOAD command asks the Kernal to load a file, it gives the
** Kernal a pointer to a file-name string. CC65's CBM programs use that
** pointer to give a copy of the program's name to main()'s argv[0] parameter.
** But, when BASIC uses a string literal that is in a program, it points
** directly to that literal -- in the models that don't use banked RAM
** (Pet/CBM, VIC-20, and 64). The literal is overwritten by the next program
** that is loaded. So, argv[0] would point to machine code. String operations
** create a new result string -- even when that operation changes nothing. The
** result is put in the string space at the top of BASIC's memory. So, the ""+
** in this BASIC line guarantees that argv[0] will get a name from a safe place.
*/
#pragma data-name(push, "LOWCODE")
static struct line {
const char end_of_line; /* fake previous line */
const struct line* const next;
const unsigned line_num;
const char CLR_token, colon, LOAD_token, quotes[2], add_token, quote;
char name[21];
const char comma;
char unit[3];
} basic = {
'\0', &basic + 1, /* high byte of link must be non-zero */
0, 0x9C, ':', 0x93, "\"\"", 0xAA, '\"',
"\" ", /* format: "123:1234567890123456\"" */
',', "01"
};
#pragma data-name(pop)
/* These values are platform-specific. */
extern const void* vartab; /* points to BASIC program variables */
#pragma zpsym("vartab")
extern const void* memsize; /* points to top of BASIC RAM */
#pragma zpsym("memsize")
extern const struct line* txtptr; /* points to BASIC code */
#pragma zpsym("txtptr")
extern char basbuf[]; /* BASIC's input buffer */
extern void basbuf_len[];
#pragma zpsym("basbuf_len")
int __fastcall__
exec(const char *progname, const char *cmdline)
{
static int fd;
static unsigned char dv, n;
/* Exclude devices that can't load files. */
/* (Use hand optimization, to make smaller code.) */
dv = getcurrentdevice();
if(dv < 8 && __AX__ != 1 || __AX__ > 30) {
return _mappederrno(9); /* illegal device number */
}
utoa(dv, basic.unit, 10);
/* Tape files can be openned only once; skip this test for the Datasette. */
if(dv != 1) {
/* Don't try to run a program that can't be found. */
fd = cfs_open(progname, CFS_READ);
if(fd < 0) {
return -1;
}
cfs_close(fd);
}
n = 0;
do {
if((basic.name[n] = progname[n]) == '\0') {
break;
}
} while(++n < 20); /* truncate long names */
basic.name[n] = '\"';
/* This next part isn't needed by machines that put
** BASIC source and variables in different RAM banks.
*/
#if !defined(__C128__)
/* cc65 program loads might extend beyond the end of the RAM that is allowed
** for BASIC. Then, the LOAD statement would complain that it is "out of
** memory". Some pointers that say where to put BASIC program variables
** must be changed, so that we do not get that error. One pointer is
** changed here; a BASIC CLR statement changes the others. Some space is
** needed for the file-name string. Subtracting an entire RAM page allows
** better optimization of this expression.
*/
vartab = (char*)memsize - 0x0100;
#endif
/* Build the next program's argument list. */
basbuf[0] = 0x8F; /* REM token */
basbuf[1] = '\0';
if(cmdline != NULL) {
strncat(basbuf, cmdline, (size_t)basbuf_len - 2);
}
/* Tell the ROM where to find that BASIC program. */
txtptr = &basic;
/* (The return code, in ST [status], will be destroyed by LOAD.
** So, don't bother to set it here.)
*/
exit(__AX__);
}