tools: add memdumpb

In C this time. Python/Perl code is barely terser than C for these little
tools. Why bother with interpreted?
This commit is contained in:
Virgil Dupras 2019-12-08 22:31:15 -05:00
parent b56d6ca1c7
commit 8ff4b18c51
3 changed files with 82 additions and 0 deletions

1
tools/.gitignore vendored Normal file
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/memdumpb

13
tools/Makefile Normal file
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CFLAGS ?= -Wall
MEMDUMP_TGT = memdumpb
MEMDUMP_SRC = memdump.c
all: ${MEMDUMP_TGT}
${MEMDUMP_TGT}: ${MEMDUMP_SRC}
${CC} ${CFLAGS} ${MEMDUMP_SRC} -o ${MEMDUMP_TGT}
.PHONY: clean
clean:
rm -f ${MEMDUMP_TGT}

68
tools/memdump.c Normal file
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#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
/* Read specified number of bytes at specified memory address through a BASIC
* remote shell and dump it to stdout.
*/
void sendcmd(int fd, char *cmd)
{
char junk[2];
while (*cmd) {
write(fd, cmd, 1);
read(fd, &junk, 1);
cmd++;
// The other side is sometimes much slower than us and if we don't let
// it breathe, it can choke.
usleep(1000);
}
write(fd, "\n", 1);
read(fd, &junk, 2); // sends back \r\n
usleep(1000);
}
int main(int argc, char **argv)
{
if (argc != 4) {
fprintf(stderr, "Usage: ./memdump device memptr bytecount\n");
return 1;
}
unsigned int memptr = strtol(argv[2], NULL, 16);
unsigned int bytecount = strtol(argv[3], NULL, 16);
fprintf(stderr, "memptr: 0x%04x bytecount: 0x%04x.\n", memptr, bytecount);
if (memptr+bytecount > 0xffff) {
fprintf(stderr, "memptr+bytecount out of range.\n");
return 1;
}
if (!bytecount) {
// nothing to spit
return 0;
}
int fd = open(argv[1], O_RDWR|O_NOCTTY);
char s[0x20];
sprintf(s, "m=0x%04x", memptr);
sendcmd(fd, s);
read(fd, s, 2); // read prompt
for (int i=0; i<bytecount; i++) {
sendcmd(fd, "peek m");
read(fd, s, 2); // read prompt
sendcmd(fd, "print a");
for (int j=0; j<3; j++) {
read(fd, s+j, 1);
s[j+1] = 0; // always null-terminate
if (s[j] < '0') {
break;
}
}
unsigned char c = strtol(s, NULL, 10);
putchar(c);
read(fd, s, 3); // read \r\n + prompt - last char
sendcmd(fd, "m=m+1");
read(fd, s, 2); // read prompt
}
return 0;
}