OpenSolaris_b135/common/fs/pcfs.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Basic file system reading code for standalone I/O system.
* Simulates a primitive UNIX I/O system (read(), write(), open(), etc).
* Does not support writes.
*/
/*
* WARNING:
* This is currently used by installgrub for creating bootable floppy.
* The special part is diskread_callback/fileread_callback for gathering
* fileblock list.
*/
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/vnode.h>
#include <sys/fs/pc_label.h>
#include <sys/bootvfs.h>
#include <sys/filep.h>
#include "pcfilep.h"
#if defined(_BOOT)
#include "../common/util.h"
#elif defined(_KERNEL)
#include <sys/sunddi.h>
#else
#include <stdio.h>
#include <strings.h>
#include <ctype.h>
#endif
#if defined(_BOOT)
#define dprintf if (bootrd_debug) printf
#elif defined(_KERNEL)
#define printf kobj_printf
#define dprintf if (bootrd_debug) kobj_printf
/* PRINTLIKE */
extern void kobj_printf(char *, ...);
#else
#define dprintf if (bootrd_debug) printf
#endif
#define FI_STARTCLUST(fp) (*(ushort_t *)(fp)->fi_buf)
#define FI_LENGTH(fp) (*(long *)((fp)->fi_buf + 4))
extern int bootrd_debug;
extern void *bkmem_alloc(size_t);
extern void bkmem_free(void *, size_t);
/*
* NOTE: The fileread_callback is set by the calling program
* during a file read. diskread_callback is set to fileread_callback
* only if reading a file block. It needs to be NULL while reading
* cluster blocks.
*/
extern int (*diskread_callback)(int, int);
extern int (*fileread_callback)(int, int);
/*
* Local prototypes
*/
static int lookuppn(char *, _dir_entry_p);
static fileid_t *find_fp(int);
static void *readblock(int, int);
static int fat_map(int, int);
static int cluster_valid(long, int);
static int fat_ctodb(int, int);
static int bpcfs_mountroot(char *str);
static int bpcfs_unmountroot(void);
static int bpcfs_open(char *str, int flags);
static int bpcfs_close(int fd);
static void bpcfs_closeall(void);
static ssize_t bpcfs_read(int fdesc, char *buf, size_t count);
static off_t bpcfs_lseek(int fdesc, off_t addr, int whence);
static fileid_t *head;
static _fat_controller_p pcfsp;
/* cache the cluster */
static int nsec_cache;
static int nsec_start;
static char *cluster_cache;
/*ARGSUSED*/
static int
bpcfs_mountroot(char *str)
{
int ncluster;
if (pcfsp != NULL)
return (0); /* already mounted */
pcfsp = bkmem_alloc(sizeof (_fat_controller_t));
head = (fileid_t *)bkmem_alloc(sizeof (fileid_t));
head->fi_back = head->fi_forw = head;
head->fi_filedes = 0;
head->fi_taken = 0;
/* read of first floppy sector */
head->fi_blocknum = 0;
head->fi_count = SECSIZ;
head->fi_memp = (caddr_t)pcfsp->f_sector;
if (diskread(head)) {
printf("failed to read first sector\n");
bkmem_free(pcfsp, sizeof (*pcfsp));
pcfsp = NULL;
return (-1);
}
if (pcfsp->f_bpb.bs_spc == 0) {
printf("invalid bios paramet block\n");
return (-1);
}
pcfsp->f_rootsec =
(pcfsp->f_bpb.bs_num_fats * ltohs(pcfsp->f_bpb.bs_spf)) +
ltohs(pcfsp->f_bpb.bs_resv_sectors);
pcfsp->f_rootlen =
ltohs(pcfsp->f_bpb.bs_num_root_entries) *
sizeof (_dir_entry_t) / SECSIZ;
pcfsp->f_adjust = 0;
pcfsp->f_dclust = CLUSTER_ROOTDIR;
pcfsp->f_filesec = pcfsp->f_rootsec + pcfsp->f_rootlen;
pcfsp->f_nxtfree = CLUSTER_FIRST;
/* figure out the number of clusters in this partition */
ncluster = (((ulong_t)ltohs(pcfsp->f_bpb.bs_siv) ?
(ulong_t)ltohs(pcfsp->f_bpb.bs_siv) :
(ulong_t)ltohi(pcfsp->f_bpb.bs_siv)) -
pcfsp->f_filesec) / (ulong_t)pcfsp->f_bpb.bs_spc;
pcfsp->f_16bit = ncluster >= CLUSTER_MAX_12;
pcfsp->f_ncluster = ncluster;
/* cache the cluster */
if (pcfsp->f_16bit)
nsec_cache = (((ncluster << 1) + 511) >> 9);
else
nsec_cache = (ncluster + ((ncluster + 1) >> 1) + 511) >> 9;
cluster_cache = bkmem_alloc(nsec_cache * SECSIZ);
if (cluster_cache == NULL) {
printf("bpcfs_mountroot: out of memory\n");
bkmem_free(pcfsp, sizeof (*pcfsp));
pcfsp = NULL;
return (-1);
}
head->fi_blocknum = nsec_start =
ltohs(pcfsp->f_bpb.bs_resv_sectors) + pcfsp->f_adjust;
head->fi_count = nsec_cache * SECSIZ;
head->fi_memp = cluster_cache;
if (diskread(head)) {
printf("bpcfs_mountroot: failed to read cluster\n");
bkmem_free(pcfsp, sizeof (*pcfsp));
pcfsp = NULL;
return (-1);
}
dprintf("read cluster sectors %d starting at %d\n",
nsec_cache, nsec_start);
return (0);
}
static int
bpcfs_unmountroot(void)
{
if (pcfsp == NULL)
return (-1);
(void) bpcfs_closeall();
return (0);
}
/*
* Open a file.
*/
/*ARGSUSED*/
int
bpcfs_open(char *str, int flags)
{
static int filedes = 1;
fileid_t *filep;
_dir_entry_t d;
dprintf("open %s\n", str);
filep = (fileid_t *)bkmem_alloc(sizeof (fileid_t));
filep->fi_back = head->fi_back;
filep->fi_forw = head;
head->fi_back->fi_forw = filep;
head->fi_back = filep;
filep->fi_filedes = filedes++;
filep->fi_taken = 1;
filep->fi_path = (char *)bkmem_alloc(strlen(str) + 1);
(void) strcpy(filep->fi_path, str);
if (lookuppn(str, &d)) {
(void) bpcfs_close(filep->fi_filedes);
return (-1);
}
filep->fi_offset = 0;
FI_STARTCLUST(filep) = d.d_cluster;
FI_LENGTH(filep) = d.d_size;
dprintf("file %s size = %ld\n", str, d.d_size);
return (filep->fi_filedes);
}
int
bpcfs_close(int fd)
{
fileid_t *filep;
dprintf("close %d\n", fd);
if (!(filep = find_fp(fd)))
return (-1);
if (filep->fi_taken == 0 || filep == head) {
printf("File descripter %d no allocated!\n", fd);
return (-1);
}
/* unlink and deallocate node */
filep->fi_forw->fi_back = filep->fi_back;
filep->fi_back->fi_forw = filep->fi_forw;
bkmem_free(filep->fi_path, strlen(filep->fi_path) + 1);
bkmem_free((char *)filep, sizeof (fileid_t));
dprintf("close done\n");
return (0);
}
static void
bpcfs_closeall(void)
{
fileid_t *filep;
while ((filep = head->fi_forw) != head)
if (filep->fi_taken && bpcfs_close(filep->fi_filedes))
printf("Filesystem may be inconsistent.\n");
bkmem_free(pcfsp, sizeof (*pcfsp));
bkmem_free(head, sizeof (fileid_t));
pcfsp = NULL;
head = NULL;
}
static ssize_t
bpcfs_read(int fd, caddr_t b, size_t c)
{
ulong_t sector;
uint_t count = 0, xfer, i;
char *block;
ulong_t off, blk;
int rd, spc;
fileid_t *fp;
dprintf("bpcfs_read: fd = %d, buf = %p, size = %d\n",
fd, (void *)b, c);
fp = find_fp(fd);
if (fp == NULL) {
printf("invalid file descriptor %d\n", fd);
return (-1);
}
spc = pcfsp->f_bpb.bs_spc;
off = fp->fi_offset;
blk = FI_STARTCLUST(fp);
rd = blk == CLUSTER_ROOTDIR ? 1 : 0;
spc = pcfsp->f_bpb.bs_spc;
off = fp->fi_offset;
blk = FI_STARTCLUST(fp);
rd = (blk == CLUSTER_ROOTDIR) ? 1 : 0;
if ((c = MIN(FI_LENGTH(fp) - off, c)) == 0)
return (0);
while (off >= pcfsp->f_bpb.bs_spc * SECSIZ) {
blk = fat_map(blk, rd);
off -= pcfsp->f_bpb.bs_spc * SECSIZ;
if (!cluster_valid(blk, rd)) {
printf("bpcfs_read: invalid cluster: %ld, %d\n",
blk, rd);
return (-1);
}
}
while (count < c) {
sector = fat_ctodb(blk, rd);
diskread_callback = fileread_callback;
for (i = ((off / SECSIZ) % pcfsp->f_bpb.bs_spc); i < spc; i++) {
xfer = MIN(SECSIZ - (off % SECSIZ), c - count);
if (xfer == 0)
break; /* last sector done */
block = (char *)readblock(sector + i, 1);
if (block == NULL) {
return (-1);
}
dprintf("bpcfs_read: read %d bytes\n", xfer);
if (diskread_callback == NULL)
(void) bcopy(&block[off % SECSIZ], b, xfer);
count += xfer;
off += xfer;
b += xfer;
}
diskread_callback = NULL;
if (count < c) {
blk = fat_map(blk, rd);
if (!cluster_valid(blk, rd)) {
printf("bpcfs_read: invalid cluster: %ld, %d\n",
blk, rd);
break;
}
}
}
fp->fi_offset += count;
return (count);
}
/*
* This version of seek() only performs absolute seeks (whence == 0).
*/
static off_t
bpcfs_lseek(int fd, off_t addr, int whence)
{
fileid_t *filep;
dprintf("lseek %d, off = %lx\n", fd, addr);
if (!(filep = find_fp(fd)))
return (-1);
switch (whence) {
case SEEK_CUR:
filep->fi_offset += addr;
break;
case SEEK_SET:
filep->fi_offset = addr;
break;
default:
case SEEK_END:
printf("lseek(): invalid whence value %d\n", whence);
break;
}
filep->fi_blocknum = addr / DEV_BSIZE;
filep->fi_count = 0;
return (0);
}
static fileid_t *
find_fp(int fd)
{
fileid_t *filep = head;
if (fd >= 0) {
while ((filep = filep->fi_forw) != head)
if (fd == filep->fi_filedes)
return (filep->fi_taken ? filep : 0);
}
return (0);
}
static int
cluster_valid(long c, int rd)
{
return ((rd && (c == 0)) ? 1 : (c >= CLUSTER_RES_16_0 ? 0 : c));
}
static int
fat_ctodb(int blk, int r)
{
uint_t s;
s = r ? blk + pcfsp->f_rootsec + pcfsp->f_adjust :
((blk - 2) * pcfsp->f_bpb.bs_spc) +
pcfsp->f_filesec + pcfsp->f_adjust;
return (s);
}
static int
fat_map(int blk, int rootdir)
{
ulong_t sectn, fat_index;
uchar_t *fp;
if (rootdir) {
return (blk > pcfsp->f_rootlen ? CLUSTER_EOF : blk + 1);
}
/* ---- Find out what sector this cluster is in ---- */
fat_index = (pcfsp->f_16bit) ? ((ulong_t)blk << 1) :
((ulong_t)blk + ((uint_t)blk >> 1));
sectn = (fat_index / SECSIZ) + ltohs(pcfsp->f_bpb.bs_resv_sectors)
+ pcfsp->f_adjust;
/*
* Read two sectors so that if our fat_index points at the last byte
* byte we'll have the data needed. This is only a problem for fat12
* entries.
*/
if (!(fp = (uchar_t *)readblock(sectn, 2))) {
printf("fat_map: bad cluster\n");
return (CLUSTER_BAD_16);
}
fp += (fat_index % SECSIZ);
if (pcfsp->f_16bit)
blk = fp[0] | (fp[1] << 8);
else {
if (blk & 1)
blk = ((fp[0] >> 4) & 0xf) | (fp[1] << 4);
else
blk = ((fp[1] & 0xf) << 8) | fp[0];
/*
* This makes compares easier because we can just compare
* against one value instead of two.
*/
if (blk >= CLUSTER_RES_12_0)
blk |= CLUSTER_RES_16_0;
}
return (blk);
}
static int
namecmp(char *pn, char *dn, int cs)
{
dprintf("namecmp %s, %s, len = %d\n", pn, dn, cs);
/* starting char must match */
while (*pn && *dn) {
--cs;
if (toupper(*pn++) != toupper(*dn++))
return (1);
}
dprintf("namecmp: cs = %d\n", cs);
/* remainder should be either ~# or all spaces */
if (cs > 0 && *dn == '~')
return (0);
while (cs > 0) {
if (*dn++ != ' ')
return (1);
--cs;
}
return (0);
}
static int
dircmp(char *name, char *d_name, char *d_ext)
{
int ret;
char *sep, *ext;
sep = (char *)strchr(name, '.');
if (sep) {
*sep = '\0';
ext = sep + 1;
} else
ext = " ";
if (namecmp(name, d_name, NAMESIZ) || namecmp(ext, d_ext, EXTSIZ))
ret = 1;
else
ret = 0;
if (sep)
*sep = '.';
return (ret);
}
static int
lookup(char *n, _dir_entry_p dp, ulong_t dir_blk)
{
int spc = pcfsp->f_bpb.bs_spc;
int rd = (dir_blk == CLUSTER_ROOTDIR ? 1 : 0);
_dir_entry_p dxp;
int j, sector;
dprintf("lookup: name = %s\n", n);
while (cluster_valid(dir_blk, rd)) {
sector = fat_ctodb(dir_blk, rd);
dxp = readblock(sector, 1); /* read one sector */
if (dxp == NULL)
return (0);
for (j = 0; j < DIRENTS * spc; j++, dxp++) {
dprintf("lookup: dir entry %s.%s;\n",
dxp->d_name, dxp->d_ext);
if (dxp->d_name[0] == 0)
return (0);
if ((uchar_t)dxp->d_name[0] != 0xE5 &&
(dxp->d_attr & (DE_LABEL|DE_HIDDEN)) == 0 &&
dircmp(n, dxp->d_name, dxp->d_ext) == 0) {
dprintf("lookup: match found\n");
(void) bcopy(dxp, dp, sizeof (*dp));
return (1);
}
}
/* next cluster */
dir_blk = fat_map(dir_blk, rd);
}
return (0);
}
static int
lookuppn(char *n, _dir_entry_p dp)
{
long dir_blk;
char name[8 + 1 + 3 + 1]; /* <8>.<3>'\0' */
char *p, *ep;
_dir_entry_t dd;
dprintf("lookuppn: path = %s\n", n);
dir_blk = pcfsp->f_dclust;
if ((*n == '\\') || (*n == '/')) {
dir_blk = CLUSTER_ROOTDIR;
while ((*n == '\\') || (*n == '/'))
n++;
if (*n == '\0') {
(void) bzero(dp, sizeof (*dp));
dp->d_cluster = CLUSTER_ROOTDIR;
dp->d_attr = DE_DIRECTORY;
return (0);
}
}
ep = &name[0] + sizeof (name);
while (*n) {
(void) bzero(name, sizeof (name));
p = &name[0];
while (*n && (*n != '\\') && (*n != '/'))
if (p != ep)
*p++ = *n++;
else {
dprintf("return, name %s is too long\n", name);
return (-1); /* name is too long */
}
while ((*n == '\\') || (*n == '/'))
n++;
if (lookup(name, &dd, dir_blk) == 0) {
dprintf("return, name %s not found\n", name);
return (-1);
}
dprintf("dd = %x:%x:%x attr = %x\n",
*(int *)&dd, *(((int *)&dd) + 1),
*(((int *)&dd) + 2), dd.d_attr);
if (*n && ((dd.d_attr & DE_DIRECTORY) == 0)) {
dprintf("return, not a directory\n");
return (-1);
}
dir_blk = dd.d_cluster;
}
(void) bcopy(&dd, dp, sizeof (dd));
return (0);
}
static void *
readblock(int sector, int nsec)
{
if (sector >= nsec_start && sector + nsec <= nsec_start + nsec_cache)
return (cluster_cache + (sector - nsec_start) * SECSIZ);
/* read disk sectors */
head->fi_blocknum = sector;
head->fi_count = nsec * SECSIZ;
head->fi_memp = head->fi_buf;
if (diskread(head)) {
printf("failed to %d sectors at %d\n", nsec, sector);
return (NULL);
}
return (head->fi_buf);
}
struct boot_fs_ops bpcfs_ops = {
"boot_pcfs",
bpcfs_mountroot,
bpcfs_unmountroot,
bpcfs_open,
bpcfs_close,
bpcfs_read,
bpcfs_lseek,
NULL
};