/* $NetBSD: disksubr_acorn.c,v 1.14 2024/01/15 19:34:13 andvar Exp $ */ /* * Copyright (c) 1998 Christopher G. Demetriou. All rights reserved. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Christopher G. Demetriou * for the NetBSD Project. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. */ /* * Copyright (c) 1982, 1986, 1988 Regents of the University of California. * All rights reserved. * * 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 REGENTS 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 REGENTS 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. * * from: @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 */ /* * Copyright (c) 1995 Mark Brinicombe * All rights reserved. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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 REGENTS 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 REGENTS 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. * * from: @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 */ #include <sys/cdefs.h> __KERNEL_RCSID(0, "$NetBSD: disksubr_acorn.c,v 1.14 2024/01/15 19:34:13 andvar Exp $"); #include <sys/param.h> #include <sys/systm.h> #include <sys/buf.h> #include <sys/disklabel.h> static int filecore_checksum(u_char *); /* * static int filecore_checksum(u_char *bootblock) * * Calculates the filecore boot block checksum. This is used to validate * a filecore boot block on the disk. If a boot block is validated then * it is used to locate the partition table. If the boot block is not * validated, it is assumed that the whole disk is NetBSD. * * The basic algorithm is: * * for (each byte in block, excluding checksum) { * sum += byte; * if (sum > 255) * sum -= 255; * } * * That's equivalent to summing all of the bytes in the block * (excluding the checksum byte, of course), then calculating the * checksum as "cksum = sum - ((sum - 1) / 255) * 255)". That * expression may or may not yield a faster checksum function, * but it's easier to reason about. * * Note that if you have a block filled with bytes of a single * value "X" (regardless of that value!) and calculate the cksum * of the block (excluding the checksum byte), you will _always_ * end up with a checksum of X. (Do the math; that can be derived * from the checksum calculation function!) That means that * blocks which contain bytes which all have the same value will * always checksum properly. That's a _very_ unlikely occurrence * (probably impossible, actually) for a valid filecore boot block, * so we treat such blocks as invalid. */ static int filecore_checksum(u_char *bootblock) { u_char byte0, accum_diff; u_int sum; int i; sum = 0; accum_diff = 0; byte0 = bootblock[0]; /* * Sum the contents of the block, keeping track of whether * or not all bytes are the same. If 'accum_diff' ends up * being zero, all of the bytes are, in fact, the same. */ for (i = 0; i < 511; ++i) { sum += bootblock[i]; accum_diff |= bootblock[i] ^ byte0; } /* * Check to see if the checksum byte is the same as the * rest of the bytes, too. (Note that if all of the bytes * are the same except the checksum, a checksum compare * won't succeed, but that's not our problem.) */ accum_diff |= bootblock[i] ^ byte0; /* All bytes in block are the same; call it invalid. */ if (accum_diff == 0) return (-1); return (sum - ((sum - 1) / 255) * 255); } int filecore_label_read(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, struct cpu_disklabel *osdep, const char **msgp, int *cylp, int *netbsd_label_offp) { struct filecore_bootblock *bb; int heads; int sectors; int rv = 1; int cyl, netbsdpartoff; struct buf *bp; #ifdef __GNUC__ netbsdpartoff = 0; /* XXX -Wuninitialized */ #endif /* get a buffer and initialize it */ bp = geteblk((int)lp->d_secsize); bp->b_dev = dev; /* read the Acorn filecore boot block */ bp->b_blkno = FILECORE_BOOT_SECTOR; bp->b_bcount = lp->d_secsize; bp->b_flags |= B_READ; bp->b_cylinder = bp->b_blkno / lp->d_secpercyl; (*strat)(bp); /* * if successful, validate boot block and * locate partition table */ if (biowait(bp)) { *msgp = "filecore boot block I/O error"; goto out; } bb = (struct filecore_bootblock *)bp->b_data; /* Validate boot block */ if (bb->checksum != filecore_checksum((u_char *)bb)) { /* * Invalid boot block so lets assume the * entire disc is NetBSD */ rv = 0; goto out; } /* Get some information from the boot block */ cyl = bb->partition_cyl_low + (bb->partition_cyl_high << 8); heads = bb->heads; sectors = bb->secspertrack; /* Do we have a NETBSD partition table ? */ if (bb->partition_type == PARTITION_FORMAT_RISCBSD) { #ifdef DEBUG_LABEL printf("%s; heads = %d nsectors = %d\n", __func__, heads, sectors); #endif netbsdpartoff = cyl * heads * sectors; } else if (bb->partition_type == PARTITION_FORMAT_RISCIX) { struct riscix_partition_table *rpt; int loop; /* * We have a RISCiX partition table :-( groan * * Read the RISCiX partition table and see if * there is a NetBSD partition */ bp->b_blkno = cyl * heads * sectors; #ifdef DEBUG_LABEL printf("%s: Found RiscIX partition table @ %" PRId64 "\n", __func__, bp->b_blkno); #endif bp->b_cylinder = bp->b_blkno / lp->d_secpercyl; bp->b_bcount = lp->d_secsize; bp->b_oflags &= ~(BO_DONE); bp->b_flags |= B_READ; (*strat)(bp); /* * if successful, locate disk label within block * and validate */ if (biowait(bp)) { *msgp = "disk label I/O error"; goto out; } rpt = (struct riscix_partition_table *)bp->b_data; #ifdef DEBUG_LABEL for (loop = 0; loop < NRISCIX_PARTITIONS; ++loop) printf("%s: p%d: %16s %08x %08x %08x\n", __func__, loop, rpt->partitions[loop].rp_name, rpt->partitions[loop].rp_start, rpt->partitions[loop].rp_length, rpt->partitions[loop].rp_type); #endif for (loop = 0; loop < NRISCIX_PARTITIONS; ++loop) { if (strcmp(rpt->partitions[loop].rp_name, "RiscBSD") == 0 || strcmp(rpt->partitions[loop].rp_name, "NetBSD") == 0 || strcmp(rpt->partitions[loop].rp_name, "Empty:") == 0) { netbsdpartoff = rpt->partitions[loop].rp_start; break; } } if (loop == NRISCIX_PARTITIONS) { *msgp = "NetBSD partition identifier string not found."; goto out; } } else { *msgp = "Invalid partition format"; goto out; } *cylp = cyl; *netbsd_label_offp = netbsdpartoff; *msgp = NULL; out: brelse(bp, 0); return (rv); } /* * Return -1 not found, 0 found positive errno */ int filecore_label_locate(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, struct cpu_disklabel *osdep, int *cylp, int *netbsd_label_offp) { struct filecore_bootblock *bb; int heads; int sectors; int rv; int cyl, netbsdpartoff; struct buf *bp; /* get a buffer and initialize it */ bp = geteblk((int)lp->d_secsize); bp->b_dev = dev; /* read the filecore boot block */ #ifdef DEBUG_LABEL printf("%s: Reading boot block\n", __func__); #endif bp->b_blkno = FILECORE_BOOT_SECTOR; bp->b_bcount = lp->d_secsize; bp->b_flags |= B_READ; bp->b_cylinder = bp->b_blkno / lp->d_secpercyl; (*strat)(bp); /* * if successful, validate boot block and locate * partition table */ if ((rv = biowait(bp)) != 0) { goto out; } bb = (struct filecore_bootblock *)bp->b_data; rv = 0; /* Validate boot block */ if (bb->checksum != filecore_checksum((u_char *)bb)) { /* * Invalid boot block so lets assume the * entire disc is NetBSD */ #ifdef DEBUG_LABEL printf("%s: Bad filecore boot block (incorrect checksum)\n", __func__); #endif rv = -1; goto out; } /* Do we have a NetBSD partition ? */ if (bb->partition_type != PARTITION_FORMAT_RISCBSD) { #ifdef DEBUG_LABEL printf("%s: Invalid partition format\n", __func__); #endif rv = EINVAL; goto out; } cyl = bb->partition_cyl_low + (bb->partition_cyl_high << 8); heads = bb->heads; sectors = bb->secspertrack; #ifdef DEBUG_LABEL printf("%s: heads = %d nsectors = %d\n", __func__, heads, sectors); #endif netbsdpartoff = cyl * heads * sectors; *cylp = cyl; *netbsd_label_offp = netbsdpartoff; out: brelse(bp, 0); return (rv); }
