freebsd-dev/sys/i386/boot/dosboot/fs.h
Poul-Henning Kamp b8e4cd2bb3 This is a MS-DOS program, but is does something useful for us:
It boots FreeBSD from a running MS-DOS system.

It's compiled using some MS-DOS tools, but there is a binary
hidden in the uuencoded file.  (Go ahead, flame me if you can come up
with a solution for the problem.  Just saying "this is bad" doesn't count!)

Rod, you were right: one would have to deal with weird interfaces to the
memory managers, and it seems that Christian found them all, and made them
work.

Thanks Christian!

Reviewed by:	phk
Submitted by:	DI. Christian Gusenbauer <cg@fimp01.fim.uni-linz.ac.at>

Christians README:
------------------

Hi Everybody!

This is version 1.5 of "fbsdboot", a program that allows you to boot a kernel
from a MS-DOS partition or a FreeBSD partition. This program runs using DOS.
It works with various memory managers (like  EMM386, 386MAX) under certain
circumstances.

First, a FreeBSD kernel is always loaded to memory starting at 0x100000. To
assure that loading the kernel *does not* overwrite memory used by memory
managers, high memory for the kernel is allocated and after loading the kernel
it's moved to 0x100000.

Second, there are many ways to switch to protected mode which is necessary to
start the kernel. Each BIOS gives you the possibility to use INT15H (AH=89H)
to do that. But some memory-managers like 386max does not allow you to use
this method.

An other way to do the switch is to use DPMI services, but they do not
guarantee, that the protected mode application is executed with privilege
level 0. Therefore this method is *not* used.

VCPI services offer another way to switch to protected mode, and VCPI servers
are built into "emm386.exe", "386max" and "qemm". That's why, this method is
implemented in fbsdboot.exe.

Fbsdboot.exe tries to switch to protected mode using VCPI services. If they're
not available INT15H is used to do the switch. If that fails, it's not possible
for this version of fbsdboot.exe to boot a kernel :-(.

You can get commandline options of fbsdboot if you start it with "-?" as option!

I don't know, if fbsdboot works with QEMM, as I don't have the possibility to
test it.

Enjoy and have fun!

Christian.
cg@fimp01.fim.uni-linz.ac.at


PS: Many thanks to Bruce Evans for his assistance!
1995-02-15 04:45:50 +00:00

466 lines
19 KiB
C

/*
* Copyright (c) 1982, 1986 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. 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: @(#)fs.h 7.12 (Berkeley) 5/8/91
* $Id: fs.h,v 1.6 1993/12/19 22:51:09 alm Exp $
*/
#ifndef _UFS_FS_H_
#define _UFS_FS_H_ 1
#define MAXFRAG 8
/*
* Each disk drive contains some number of file systems.
* A file system consists of a number of cylinder groups.
* Each cylinder group has inodes and data.
*
* A file system is described by its super-block, which in turn
* describes the cylinder groups. The super-block is critical
* data and is replicated in each cylinder group to protect against
* catastrophic loss. This is done at `newfs' time and the critical
* super-block data does not change, so the copies need not be
* referenced further unless disaster strikes.
*
* For file system fs, the offsets of the various blocks of interest
* are given in the super block as:
* [fs->fs_sblkno] Super-block
* [fs->fs_cblkno] Cylinder group block
* [fs->fs_iblkno] Inode blocks
* [fs->fs_dblkno] Data blocks
* The beginning of cylinder group cg in fs, is given by
* the ``cgbase(fs, cg)'' macro.
*
* The first boot and super blocks are given in absolute disk addresses.
* The byte-offset forms are preferred, as they don't imply a sector size.
*/
#define BBSIZE 8192
#define SBSIZE 8192
#define BBOFF ((off_t)(0))
#define SBOFF ((off_t)(BBOFF + BBSIZE))
#define BBLOCK ((daddr_t)(0))
#define SBLOCK ((daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
/*
* Addresses stored in inodes are capable of addressing fragments
* of `blocks'. File system blocks of at most size MAXBSIZE can
* be optionally broken into 2, 4, or 8 pieces, each of which is
* addressible; these pieces may be DEV_BSIZE, or some multiple of
* a DEV_BSIZE unit.
*
* Large files consist of exclusively large data blocks. To avoid
* undue wasted disk space, the last data block of a small file may be
* allocated as only as many fragments of a large block as are
* necessary. The file system format retains only a single pointer
* to such a fragment, which is a piece of a single large block that
* has been divided. The size of such a fragment is determinable from
* information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
*
* The file system records space availability at the fragment level;
* to determine block availability, aligned fragments are examined.
*
* The root inode is the root of the file system.
* Inode 0 can't be used for normal purposes and
* historically bad blocks were linked to inode 1,
* thus the root inode is 2. (inode 1 is no longer used for
* this purpose, however numerous dump tapes make this
* assumption, so we are stuck with it)
*/
#define ROOTINO ((ino_t)2)
/*
* MINBSIZE is the smallest allowable block size.
* In order to insure that it is possible to create files of size
* 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
* MINBSIZE must be big enough to hold a cylinder group block,
* thus changes to (struct cg) must keep its size within MINBSIZE.
* Note that super blocks are always of size SBSIZE,
* and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
*/
#define MINBSIZE 4096
/*
* The path name on which the file system is mounted is maintained
* in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
* the super block for this name.
* The limit on the amount of summary information per file system
* is defined by MAXCSBUFS. It is currently parameterized for a
* maximum of two million cylinders.
*/
#define MAXMNTLEN 512
#define MAXCSBUFS 32
/*
* Per cylinder group information; summarized in blocks allocated
* from first cylinder group data blocks. These blocks have to be
* read in from fs_csaddr (size fs_cssize) in addition to the
* super block.
*
* N.B. sizeof(struct csum) must be a power of two in order for
* the ``fs_cs'' macro to work (see below).
*/
struct csum {
long cs_ndir; /* number of directories */
long cs_nbfree; /* number of free blocks */
long cs_nifree; /* number of free inodes */
long cs_nffree; /* number of free frags */
};
/*
* Super block for a file system.
*/
#define FS_MAGIC 0x011954
#define FSOKAY 0x7c269d38
struct fs
{
struct fs *fs_link; /* linked list of file systems */
struct fs *fs_rlink; /* used for incore super blocks */
daddr_t fs_sblkno; /* addr of super-block in filesys */
daddr_t fs_cblkno; /* offset of cyl-block in filesys */
daddr_t fs_iblkno; /* offset of inode-blocks in filesys */
daddr_t fs_dblkno; /* offset of first data after cg */
long fs_cgoffset; /* cylinder group offset in cylinder */
long fs_cgmask; /* used to calc mod fs_ntrak */
time_t fs_time; /* last time written */
long fs_size; /* number of blocks in fs */
long fs_dsize; /* number of data blocks in fs */
long fs_ncg; /* number of cylinder groups */
long fs_bsize; /* size of basic blocks in fs */
long fs_fsize; /* size of frag blocks in fs */
long fs_frag; /* number of frags in a block in fs */
/* these are configuration parameters */
long fs_minfree; /* minimum percentage of free blocks */
long fs_rotdelay; /* num of ms for optimal next block */
long fs_rps; /* disk revolutions per second */
/* these fields can be computed from the others */
long fs_bmask; /* ``blkoff'' calc of blk offsets */
long fs_fmask; /* ``fragoff'' calc of frag offsets */
long fs_bshift; /* ``lblkno'' calc of logical blkno */
long fs_fshift; /* ``numfrags'' calc number of frags */
/* these are configuration parameters */
long fs_maxcontig; /* max number of contiguous blks */
long fs_maxbpg; /* max number of blks per cyl group */
/* these fields can be computed from the others */
long fs_fragshift; /* block to frag shift */
long fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
long fs_sbsize; /* actual size of super block */
long fs_csmask; /* csum block offset */
long fs_csshift; /* csum block number */
long fs_nindir; /* value of NINDIR */
long fs_inopb; /* value of INOPB */
long fs_nspf; /* value of NSPF */
/* yet another configuration parameter */
long fs_optim; /* optimization preference, see below */
/* these fields are derived from the hardware */
long fs_npsect; /* # sectors/track including spares */
long fs_interleave; /* hardware sector interleave */
long fs_trackskew; /* sector 0 skew, per track */
long fs_headswitch; /* head switch time, usec */
long fs_trkseek; /* track-to-track seek, usec */
/* sizes determined by number of cylinder groups and their sizes */
daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
long fs_cssize; /* size of cyl grp summary area */
long fs_cgsize; /* cylinder group size */
/* these fields are derived from the hardware */
long fs_ntrak; /* tracks per cylinder */
long fs_nsect; /* sectors per track */
long fs_spc; /* sectors per cylinder */
/* this comes from the disk driver partitioning */
long fs_ncyl; /* cylinders in file system */
/* these fields can be computed from the others */
long fs_cpg; /* cylinders per group */
long fs_ipg; /* inodes per group */
long fs_fpg; /* blocks per group * fs_frag */
/* this data must be re-computed after crashes */
struct csum fs_cstotal; /* cylinder summary information */
/* these fields are cleared at mount time */
char fs_fmod; /* super block modified flag */
char fs_clean; /* file system is clean flag */
char fs_ronly; /* mounted read-only flag */
char fs_flags; /* currently unused flag */
char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
/* these fields retain the current block allocation info */
long fs_cgrotor; /* last cg searched */
struct csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */
long fs_cpc; /* cyl per cycle in postbl */
short fs_opostbl[16][8]; /* old rotation block list head */
long fs_sparecon[55]; /* reserved for future constants */
long fs_state; /* validate fs_clean field */
union {
/* quad_t v;*/
long val[2];
} fs_qbmask; /* ~fs_bmask - for use with quad size */
union {
/* quad_t v;*/
long val[2];
} fs_qfmask; /* ~fs_fmask - for use with quad size */
long fs_postblformat; /* format of positional layout tables */
long fs_nrpos; /* number of rotaional positions */
long fs_postbloff; /* (short) rotation block list head */
long fs_rotbloff; /* (u_char) blocks for each rotation */
long fs_magic; /* magic number */
u_char fs_space[1]; /* list of blocks for each rotation */
/* actually longer */
};
/*
* Preference for optimization.
*/
#define FS_OPTTIME 0 /* minimize allocation time */
#define FS_OPTSPACE 1 /* minimize disk fragmentation */
/*
* Rotational layout table format types
*/
#define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
#define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
/*
* Macros for access to superblock array structures
*/
#define fs_postbl(fs, cylno) \
(((fs)->fs_postblformat == FS_42POSTBLFMT) \
? ((fs)->fs_opostbl[cylno]) \
: ((short *)((char *)(fs) + (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
#define fs_rotbl(fs) \
(((fs)->fs_postblformat == FS_42POSTBLFMT) \
? ((fs)->fs_space) \
: ((u_char *)((char *)(fs) + (fs)->fs_rotbloff)))
/*
* Convert cylinder group to base address of its global summary info.
*
* N.B. This macro assumes that sizeof(struct csum) is a power of two.
*/
#define fs_cs(fs, indx) \
fs_csp[(indx) >> (fs)->fs_csshift][(indx) & ~(fs)->fs_csmask]
/*
* Cylinder group block for a file system.
*/
#define CG_MAGIC 0x090255
struct cg {
struct cg *cg_link; /* linked list of cyl groups */
long cg_magic; /* magic number */
time_t cg_time; /* time last written */
long cg_cgx; /* we are the cgx'th cylinder group */
short cg_ncyl; /* number of cyl's this cg */
short cg_niblk; /* number of inode blocks this cg */
long cg_ndblk; /* number of data blocks this cg */
struct csum cg_cs; /* cylinder summary information */
long cg_rotor; /* position of last used block */
long cg_frotor; /* position of last used frag */
long cg_irotor; /* position of last used inode */
long cg_frsum[MAXFRAG]; /* counts of available frags */
long cg_btotoff; /* (long) block totals per cylinder */
long cg_boff; /* (short) free block positions */
long cg_iusedoff; /* (char) used inode map */
long cg_freeoff; /* (u_char) free block map */
long cg_nextfreeoff; /* (u_char) next available space */
long cg_sparecon[16]; /* reserved for future use */
u_char cg_space[1]; /* space for cylinder group maps */
/* actually longer */
};
/*
* Macros for access to cylinder group array structures
*/
#define cg_blktot(cgp) \
(((cgp)->cg_magic != CG_MAGIC) \
? (((struct ocg *)(cgp))->cg_btot) \
: ((long *)((char *)(cgp) + (cgp)->cg_btotoff)))
#define cg_blks(fs, cgp, cylno) \
(((cgp)->cg_magic != CG_MAGIC) \
? (((struct ocg *)(cgp))->cg_b[cylno]) \
: ((short *)((char *)(cgp) + (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
#define cg_inosused(cgp) \
(((cgp)->cg_magic != CG_MAGIC) \
? (((struct ocg *)(cgp))->cg_iused) \
: ((char *)((char *)(cgp) + (cgp)->cg_iusedoff)))
#define cg_blksfree(cgp) \
(((cgp)->cg_magic != CG_MAGIC) \
? (((struct ocg *)(cgp))->cg_free) \
: ((u_char *)((char *)(cgp) + (cgp)->cg_freeoff)))
#define cg_chkmagic(cgp) \
((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
/*
* The following structure is defined
* for compatibility with old file systems.
*/
struct ocg {
struct ocg *cg_link; /* linked list of cyl groups */
struct ocg *cg_rlink; /* used for incore cyl groups */
time_t cg_time; /* time last written */
long cg_cgx; /* we are the cgx'th cylinder group */
short cg_ncyl; /* number of cyl's this cg */
short cg_niblk; /* number of inode blocks this cg */
long cg_ndblk; /* number of data blocks this cg */
struct csum cg_cs; /* cylinder summary information */
long cg_rotor; /* position of last used block */
long cg_frotor; /* position of last used frag */
long cg_irotor; /* position of last used inode */
long cg_frsum[8]; /* counts of available frags */
long cg_btot[32]; /* block totals per cylinder */
short cg_b[32][8]; /* positions of free blocks */
char cg_iused[256]; /* used inode map */
long cg_magic; /* magic number */
u_char cg_free[1]; /* free block map */
/* actually longer */
};
/*
* Turn file system block numbers into disk block addresses.
* This maps file system blocks to device size blocks.
*/
#define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
#define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
/*
* Cylinder group macros to locate things in cylinder groups.
* They calc file system addresses of cylinder group data structures.
*/
#define cgbase(fs, c) ((daddr_t)((fs)->fs_fpg * (c)))
#define cgstart(fs, c) \
(cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
#define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
#define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
#define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
#define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
/*
* Macros for handling inode numbers:
* inode number to file system block offset.
* inode number to cylinder group number.
* inode number to file system block address.
*/
#define itoo(fs, x) ((x) % INOPB(fs))
#define itog(fs, x) ((x) / (fs)->fs_ipg)
#define itod(fs, x) \
((daddr_t)(cgimin(fs, itog(fs, x)) + \
(blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
/*
* Give cylinder group number for a file system block.
* Give cylinder group block number for a file system block.
*/
#define dtog(fs, d) ((d) / (fs)->fs_fpg)
#define dtogd(fs, d) ((d) % (fs)->fs_fpg)
/*
* Extract the bits for a block from a map.
* Compute the cylinder and rotational position of a cyl block addr.
*/
#define blkmap(fs, map, loc) \
(((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
#define cbtocylno(fs, bno) \
((bno) * NSPF(fs) / (fs)->fs_spc)
#define cbtorpos(fs, bno) \
(((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
(bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
(fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
/*
* The following macros optimize certain frequently calculated
* quantities by using shifts and masks in place of divisions
* modulos and multiplications.
*/
#define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
((loc) & ~(fs)->fs_bmask)
#define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
((loc) & ~(fs)->fs_fmask)
#define lblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
((blk) << (fs)->fs_bshift)
#define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
((loc) >> (fs)->fs_bshift)
#define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
((loc) >> (fs)->fs_fshift)
#define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
(((size) + (fs)->fs_bsize - 1) & (fs)->fs_bmask)
#define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
(((size) + (fs)->fs_fsize - 1) & (fs)->fs_fmask)
#define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
((frags) >> (fs)->fs_fragshift)
#define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
((blks) << (fs)->fs_fragshift)
#define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
((fsb) & ((fs)->fs_frag - 1))
#define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
((fsb) &~ ((fs)->fs_frag - 1))
/*
* Determine the number of available frags given a
* percentage to hold in reserve
*/
#define freespace(fs, percentreserved) \
(blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
(fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100))
/*
* Determining the size of a file block in the file system.
*/
#define blksize(fs, ip, lbn) \
(((lbn) >= NDADDR || (ip)->i_size >= ((lbn) + 1) << (fs)->fs_bshift) \
? (fs)->fs_bsize \
: (fragroundup(fs, blkoff(fs, (ip)->i_size))))
#define dblksize(fs, dip, lbn) \
(((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \
? (fs)->fs_bsize \
: (fragroundup(fs, blkoff(fs, (dip)->di_size))))
/*
* Number of disk sectors per block; assumes DEV_BSIZE byte sector size.
*/
#define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
#define NSPF(fs) ((fs)->fs_nspf)
/*
* INOPB is the number of inodes in a secondary storage block.
*/
#define INOPB(fs) ((fs)->fs_inopb)
#define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
/*
* NINDIR is the number of indirects in a file system block.
*/
#define NINDIR(fs) ((fs)->fs_nindir)
#ifdef KERNEL
extern void fserr(struct fs *, int /*uid_t*/, const char *);
extern void fragacct(struct fs *, int, long *, int);
extern int isblock(struct fs *, u_char *, daddr_t);
extern void clrblock(struct fs *, u_char *, daddr_t);
extern void setblock(struct fs *, u_char *, daddr_t);
extern ino_t dirpref(struct fs *);
extern daddr_t mapsearch(struct fs *, struct cg *, daddr_t, int);
#endif /* KERNEL */
#endif /* _UFS_FS_H_ */