/* * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009 * The President and Fellows of Harvard College. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <assert.h> #include <stdint.h> #include <string.h> #include <errno.h> #include <fcntl.h> #include <err.h> #include "support.h" #include "disk.h" #define HOSTSTRING "System/161 Disk Image" #define BLOCKSIZE 512 #ifndef EINTR #define EINTR 0 #endif static int fd=-1; static uint32_t nblocks; /* * Open a disk. If we're built for the host OS, check that it's a * System/161 disk image, and then ignore the header block. */ void opendisk(const char *path) { struct stat statbuf; assert(fd<0); fd = open(path, O_RDWR); if (fd<0) { err(1, "%s", path); } if (fstat(fd, &statbuf)) { err(1, "%s: fstat", path); } nblocks = statbuf.st_size / BLOCKSIZE; #ifdef HOST nblocks--; { char buf[64]; int len; do { len = read(fd, buf, sizeof(buf)-1); if (len < 0 && (errno==EINTR || errno==EAGAIN)) { continue; } } while (0); buf[len] = 0; buf[strlen(HOSTSTRING)] = 0; if (strcmp(buf, HOSTSTRING)) { errx(1, "%s: Not a System/161 disk image", path); } } #endif } /* * Return the block size. (This is fixed, but still...) */ uint32_t diskblocksize(void) { assert(fd>=0); return BLOCKSIZE; } /* * Return the device/image size in blocks. */ uint32_t diskblocks(void) { assert(fd>=0); return nblocks; } /* * Write a block. */ void diskwrite(const void *data, uint32_t block) { const char *cdata = data; uint32_t tot=0; int len; assert(fd>=0); #ifdef HOST // skip over disk file header block++; #endif if (lseek(fd, block*BLOCKSIZE, SEEK_SET)<0) { err(1, "lseek"); } while (tot < BLOCKSIZE) { len = write(fd, cdata + tot, BLOCKSIZE - tot); if (len < 0) { if (errno==EINTR || errno==EAGAIN) { continue; } err(1, "write"); } if (len==0) { err(1, "write returned 0?"); } tot += len; } } /* * Read a block. */ void diskread(void *data, uint32_t block) { char *cdata = data; uint32_t tot=0; int len; assert(fd>=0); #ifdef HOST // skip over disk file header block++; #endif if (lseek(fd, block*BLOCKSIZE, SEEK_SET)<0) { err(1, "lseek"); } while (tot < BLOCKSIZE) { len = read(fd, cdata + tot, BLOCKSIZE - tot); if (len < 0) { if (errno==EINTR || errno==EAGAIN) { continue; } err(1, "read"); } if (len==0) { err(1, "unexpected EOF in mid-sector"); } tot += len; } } /* * Close the disk. */ void closedisk(void) { assert(fd>=0); if (close(fd)) { err(1, "close"); } fd = -1; }