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| -rw-r--r-- | .gitignore | 8 | ||||
| -rw-r--r-- | README | 54 | ||||
| -rw-r--r-- | uioctl.c | 232 |
3 files changed, 294 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..f466019 --- /dev/null +++ b/.gitignore @@ -0,0 +1,8 @@ +*.o +*.a +*.pyc +*~ +*.swp +.* +*.tmp +*.old @@ -0,0 +1,54 @@ + + _ _ _ + _ _(_) ___ ___| |_| | + | | | | |/ _ \ / __| __| | + | |_| | | (_) | (__| |_| | + \__,_|_|\___/ \___|\__|_| + + +trivial utility for manipulating simple Linux UIO devices ("Userspace I/O"). +eg, reading and writing bytes to memory mapped devices or monitoring +interrupts. +can list all devices and their mappings. +little-endian by default. + +------------------------------------------------------------------------------- + +gcc uioctl.c -o uioctl + +------------------------------------------------------------------------------- + +./uioctl -h +little-endian by default + -w select word width (default: 4) + -s size of mmap (default: base + length, rounded up to PAGE_SIZE) + +./uioctl /dev/uio0 0 -n 100 -w 1 -r 0 +./uioctl /dev/uio0 0x818 0 +./uioctl /dev/uio0 -m +./uioctl -l + +also, secret trick: + +sudo ./uioctl /dev/mem 0x818 -n 5 + +BUT WAIT? + +hexdump -C /dev/uio0 -s 0x + +------------------------------------------------------------------------------- + +UIO: user-space drivers (2007) +https://lwn.net/Articles/232575/ + +The Userspace I/O HOWTO (2006-2009) +https://www.kernel.org/doc/htmldocs/uio-howto/ + +Simple userland drivers for FPGA interfaces (eg, AXI) +http://svenand.blogdrive.com/archive/150.html + +devmem2.c: Simple program to read/write from/to any location in memory +http://sources.buildroot.net/devmem2.c + +pydevmem +https://github.com/kylemanna/pydevmem diff --git a/uioctl.c b/uioctl.c new file mode 100644 index 0000000..6558844 --- /dev/null +++ b/uioctl.c @@ -0,0 +1,232 @@ +/* + * uioctl.c: Userspace I/O manipulation utility + * + * Copyright (C) 2013, Bryan Newbold <bnewbold@leaflabs.com> + * + * ISC License: Permission to use, copy, modify, and/or distribute this + * software for any purpose with or without fee is hereby granted, provided + * that the above copyright notice and this permission notice appear in all + * copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL + * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY + * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION + * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + * Changelog: + * 2013-12-04: bnewbold: Initial version; missing width management, list mode + * + */ + +#include <errno.h> +#include <getopt.h> +#include <inttypes.h> +#include <stdio.h> +#include <fcntl.h> +#include <stdlib.h> +#include <stdint.h> +#include <unistd.h> +#include <sys/mman.h> +#include <sys/timeb.h> + +#define DEFAULT_WIDTH 4 +#define PROGRAM_NAME "uioctl" + +enum mode_type { + MODE_READ, + MODE_WRITE, + MODE_LIST, + MODE_MONITOR +}; + +static void usage(int exit_status) { + fprintf(exit_status == EXIT_SUCCESS ? stdout : stderr, + "Usage: %s [options] [-l] [/dev/uioX [-m] [<addr> [<value>]]]\n" + "\n" + "Functions:\n" + " monitor (-m) the device for interrupts\n" + " list (-l) all devices and their mappings\n" + " read words from <addr>\n" + " write <value> to <addr> (will zero-pad word width)\n" + "\n" + "Options:\n" + " -r\tselect the device's memory region to map (default: 0)\n" + " -w\tword size (in bytes; default: %d)\n" + " -n\tnumber of words to read (in words; default: 1)\n" + " -x\texit with success after the first interrupt (implies -m mode)\n" + , + PROGRAM_NAME, DEFAULT_WIDTH); + exit(exit_status); +} + +static void list_devices() { + // TODO: + // - try to list /sys/devices/uio* + // - for each in the above, print memory regions + fprintf(stderr, "listing not yet implemented\n"); + exit(EXIT_FAILURE); +} + +static void monitor(char *fpath, int forever) { + char buf[4]; + int bytes; + int fd; + struct timeb tp; + char startval[] = {0,0,0,1}; + + printf("Waiting for interrupts on %s\n", fpath); + fd = open(fpath, O_RDWR); + if (fd < 1) { + perror("uioctl"); + fprintf(stderr, "Couldn't open UIO device file: %s\n", fpath); + exit(EXIT_FAILURE); + } + do { + bytes = pwrite(fd, &startval, 4, 0); + if (bytes != 4) { + perror("uioctl"); + fprintf(stderr, "Problem clearing device file\n"); + exit(EXIT_FAILURE); + } + //lseek(fd, 0, SEEK_SET); + bytes = pread(fd, buf, 4, 0); + ftime(&tp); + if (bytes != 4) { + perror("uioctl"); + fprintf(stderr, "Problem reading from device file\n"); + exit(EXIT_FAILURE); + } + printf("[%ld.%03d] interrupt: %d\n", tp.time, tp.millitm, + (buf[3] * 16777216 + buf[2] * 65536 + buf[1] * 256 + buf[0])); + } while (forever); + close(fd); + exit(EXIT_SUCCESS); +} + +int main(int argc, char *argv[]) { + int c; + int fd; + enum mode_type mode = MODE_READ; + char *fpath; + void *ptr; + int map_size, value, addr; + int region = 0; + int count = 1; + int width = DEFAULT_WIDTH; + int forever = 1; + + while((c = getopt(argc, argv, "hlmxr:n:w:")) != -1) { + errno = 0; + switch(c) { + case 'h': + usage(EXIT_SUCCESS); + case 'l': + list_devices(); + case 'm': + mode = MODE_MONITOR; + break; + case 'x': + mode = MODE_MONITOR; + forever = 0; + break; + case 'r': + region = strtoul(optarg, NULL, 0); + if (errno) { + perror("uioctl"); + exit(EXIT_FAILURE); + } + if (region != 0) { + fprintf(stderr, "region != 0 not yet implemented\n"); + exit(EXIT_FAILURE); + } + break; + case 'n': + count = strtoul(optarg, NULL, 0); + if (errno) { + perror("uioctl"); + exit(EXIT_FAILURE); + } + break; + case 'w': + width = strtoul(optarg, NULL, 0); + if (errno) { + perror("uioctl"); + exit(EXIT_FAILURE); + } + if (width != 4) { + fprintf(stderr, "width != 4 not yet implemented\n"); + exit(EXIT_FAILURE); + } + break; + default: + fprintf(stderr, "Unexpected argument; try -h\n"); + exit(EXIT_FAILURE); + } + } + + if (mode == MODE_MONITOR) { + if ((argc - optind) != 1) { + fprintf(stderr, "Wrong number of arguments; try -h\n"); + exit(EXIT_FAILURE); + } + fpath = argv[optind]; + monitor(fpath, forever); + } + if (mode == MODE_READ) { + if ((argc - optind) == 2) { + fpath = argv[optind++]; + errno = 0; + addr = strtoul(argv[optind++], NULL, 0); + if (errno) { + perror("uioctl"); + exit(EXIT_FAILURE); + } + //printf("addr: 0x%08x\n", addr); + } else + if ((argc - optind) == 3) { + mode = MODE_WRITE; + fpath = argv[optind++]; + errno = 0; + addr = strtoul(argv[optind++], NULL, 0); + value = strtoul(argv[optind++], NULL, 0); + if (errno) { + perror("uioctl"); + exit(EXIT_FAILURE); + } + //printf("addr: 0x%08x\n", addr); + //printf("value: 0x%08x\n", value); + } else { + fprintf(stderr, "Wrong number of arguments; try -h\n"); + exit(EXIT_FAILURE); + } + } + + map_size = count * width; + + fd = open(fpath, O_RDWR|O_SYNC); + if (fd < 1) { + perror("uioctl"); + fprintf(stderr, "Couldn't open UIO device file: %s\n", fpath); + return EXIT_FAILURE; + } + ptr = mmap(NULL, map_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + + /* TODO: do the things... */ + /* value = *((unsigned *) (ptr + offset); */ + if (mode == MODE_READ) { + for (; count > 0; count--) { + value = *((unsigned *) (ptr + addr)); + printf("0x%08x\t%08x\n", addr, value); + addr += width; + } + } else { + *((unsigned *)(ptr + addr)) = value; + } + + /* clean up */ + munmap(ptr, map_size); + close(fd); + + return EXIT_SUCCESS; +} |