[syslinux] [PULL 3/8] Wire up MultiFS support.
Paulo Alcantara
pcacjr at gmail.com
Wed Jul 22 16:27:25 PDT 2015
From: "Raphael S. Carvalho" <raphael.scarv at gmail.com>
This patch finishes the MultiFS support.
init_multifs gets called in the main (startup) function of ldlinux.c32,
so MultiFS will be initialized automatically.
init_multifs calls enable_multifs (lives in the core) to hook get_fs_info.
Subsequent accesses will callback the get_fs_info living in ldlinux.c32.
Cc: Gene Cumm <gene.cumm at gmail.com>
Signed-off-by: Raphael S. Carvalho <raphael.scarv at gmail.com>
Signed-off-by: Paulo Alcantara <pcacjr at zytor.com>
---
com32/elflink/ldlinux/ldlinux.c | 2 +
com32/include/syslinux/multifs_utils.h | 51 ++++++
com32/lib/syslinux/multifs_utils.c | 323 +++++++++++++++++++++++++++++++++
mk/lib.mk | 1 +
4 files changed, 377 insertions(+)
create mode 100644 com32/include/syslinux/multifs_utils.h
create mode 100644 com32/lib/syslinux/multifs_utils.c
diff --git a/com32/elflink/ldlinux/ldlinux.c b/com32/elflink/ldlinux/ldlinux.c
index 9b01dd3..97b4be2 100644
--- a/com32/elflink/ldlinux/ldlinux.c
+++ b/com32/elflink/ldlinux/ldlinux.c
@@ -303,6 +303,8 @@ __export int main(int argc __unused, char **argv)
const char *cmdline;
size_t count = 0;
+ init_multifs(); /* Init MultiFS support */
+
ldlinux_console_init();
parse_configs(&argv[1]);
diff --git a/com32/include/syslinux/multifs_utils.h b/com32/include/syslinux/multifs_utils.h
new file mode 100644
index 0000000..90ef6d6
--- /dev/null
+++ b/com32/include/syslinux/multifs_utils.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2012 Andre Ericson <de.ericson at gmail.com>
+ * Copyright (C) 2012 Paulo Cavalcanti <pcacjr at zytor.com>
+ * Copyright (C) 2013 Raphael S. Carvalho <raphael.scarv at gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+*/
+
+#ifndef MULTIDISK_UTILS_H
+#define MULTIDISK_UTILS_H
+
+#include <syslinux/partiter.h>
+#include "fs.h"
+
+struct part_node {
+ int partition;
+ struct fs_info *fs;
+ struct part_node *next;
+};
+
+struct queue_head {
+ struct part_node *first;
+ struct part_node *last;
+};
+
+/*
+ * Needs to keep ROOT_FS_OPS after fs_init()
+ * to be used by multidisk
+ */
+extern const struct fs_ops **p_ops;
+
+/*
+ * Used to initialize MultiFS support
+ */
+extern void enable_multifs(void *);
+extern void init_multifs(void);
+
+#endif /* MULTIDISK_UTILS_H */
diff --git a/com32/lib/syslinux/multifs_utils.c b/com32/lib/syslinux/multifs_utils.c
new file mode 100644
index 0000000..d243ef2
--- /dev/null
+++ b/com32/lib/syslinux/multifs_utils.c
@@ -0,0 +1,323 @@
+/*
+ * Copyright (C) 2012 Andre Ericson <de.ericson at gmail.com>
+ * Copyright (C) 2012 Paulo Cavalcanti <pcacjr at zytor.com>
+ * Copyright (C) 2013 Raphael S. Carvalho <raphael.scarv at gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+*/
+
+#include <syslinux/multifs_utils.h>
+#include "core.h"
+#include "disk.h"
+#include "cache.h"
+#include "minmax.h"
+
+/* 0x80 - 0xFF
+ * BIOS limitation */
+#define DISK_ID_OFFSET 0x80
+#define DISKS_MAX 128
+
+/* MaxTransfer for MultiFS access */
+#define MAX_TRANSFER 127
+
+static struct queue_head *parts_info[DISKS_MAX];
+
+/*
+ * Store info about the FS into a specific queue to be used later.
+ *
+ * @ret: 0 on success, -1 on failure.
+ */
+static int add_fs(struct fs_info *fs, uint8_t disk, uint8_t partition)
+{
+ struct queue_head *head = parts_info[disk];
+ struct part_node *node;
+
+ node = malloc(sizeof(struct part_node));
+ if (!node)
+ return -1;
+ node->fs = fs;
+ node->next = NULL;
+ node->partition = partition;
+
+ if (!head) {
+ head = malloc(sizeof(struct queue_head));
+ if (!head) {
+ free(node);
+ return -1;
+ }
+ head->first = head->last = node;
+ parts_info[disk] = head;
+ return 0;
+ }
+ head->last->next = node;
+ head->last = node;
+ return 0;
+}
+
+/*
+ * Check if the FS was previously allocated.
+ *
+ * @ret: return the fs on success, NULL on failure.
+ */
+static struct fs_info *get_fs(uint8_t disk, uint8_t partition)
+{
+ struct part_node *i;
+
+ for (i = parts_info[disk]->first; i; i = i->next) {
+ if (i->partition == partition)
+ return i->fs;
+ }
+ return NULL;
+}
+
+/*
+ * Attempt to find a partition based on drive and partition numbers.
+ *
+ * @ret: 0 on success, -1 on failure.
+ */
+static int find_partition(struct part_iter **_iter, struct disk_info *diskinfo,
+ int partition)
+{
+ struct part_iter *iter = NULL;
+
+ if (!(iter = pi_begin(diskinfo, 0)))
+ return -1;
+
+ do {
+ if (iter->index == partition)
+ break;
+ } while (!pi_next(iter));
+
+ if (iter->status) {
+ dprintf("MultiFS: Request disk/partition combination not found.\n");
+ goto bail;
+ }
+ dprintf("MultiFS: found 0x%llx at idex: %i and partition %i\n",
+ iter->abs_lba, iter->index, partition);
+
+ *_iter = iter;
+ return 0;
+bail:
+ pi_del(&iter);
+ return -1;
+}
+
+/*
+ * Get a number till the delimiter is found.
+ *
+ * @ret: addr to delimiter+1 on success, NULL on failure.
+ */
+static const char *get_num(const char *p, char delimiter, uint8_t *data)
+{
+ uint32_t n = 0;
+
+ while (*p) {
+ if (*p < '0' || *p > '9')
+ break;
+
+ n = (n * 10) + (*p - '0');
+ p++;
+
+ if (*p == delimiter) {
+ p++; /* Skip delimiter */
+ *data = min(n, UINT8_MAX); /* Avoid overflow */
+ return p;
+ }
+ }
+ return NULL;
+}
+
+/*
+ * Parse MultiFS path. Syntax:
+ * (hd[disk number],[partition number])/path/to/file
+ *
+ * @ret: Returns syntax validity.
+ */
+static int parse_multifs_path(const char **path, uint8_t *hdd,
+ uint8_t *partition)
+{
+ const char *p = *path;
+ static const char *cwd = ".";
+
+ *hdd = *partition = 0;
+ p++; /* Skip open parentheses */
+
+ /* Get hd number (Range: 0 - (DISKS_MAX - 1)) */
+ if (*p != 'h' || *(p + 1) != 'd')
+ return -1;
+
+ p += 2; /* Skip 'h' and 'd' */
+ p = get_num(p, ',', hdd);
+ if (!p)
+ return -1;
+ if (*hdd >= DISKS_MAX) {
+ printf("MultiFS: hdd is out of range: 0-%d\n", DISKS_MAX - 1);
+ return -1;
+ }
+
+ /* Get partition number (Range: 0 - 0xFF) */
+ p = get_num(p, ')', partition);
+ if (!p)
+ return -1;
+
+ if (*p == '\0') {
+ /* Assume it's a cwd request */
+ p = cwd;
+ }
+
+ *path = p;
+ dprintf("MultiFS: hdd: %u partition: %u path: %s\n",
+ *hdd, *partition, *path);
+ return 0;
+}
+
+/*
+ * Set up private struct based on paramaters.
+ * This structure will be used later to set up a device
+ * to (disk x,partition y).
+ *
+ * @devno: Device number (range: 0 - (DISKS_MAX - 1)).
+ * @part_start: Start LBA.
+ * @bsHeads: Number of heads.
+ * @bsSecPerTrack: Sectors per track.
+ */
+static void *get_private(uint8_t devno, uint64_t part_start,
+ uint16_t bsHeads, uint16_t bsSecPerTrack)
+{
+ static com32sys_t regs;
+ static struct bios_disk_private priv;
+
+ priv.regs = ®s;
+
+ regs.edx.b[0] = devno;
+ regs.edx.b[1] = 0; // TODO: cdrom ... always 0???
+ regs.ecx.l = part_start & 0xFFFFFFFF;
+ regs.ebx.l = part_start >> 32;
+ regs.esi.w[0] = bsHeads;
+ regs.edi.w[0] = bsSecPerTrack;
+ regs.ebp.l = MAX_TRANSFER; // TODO: should it be pre-defined???
+
+ return (void *) &priv;
+}
+
+/*
+ * 1) Set up a new device based on the disk and the partition.
+ * 2) Find which file system is installed in this device.
+ * 3) Set up fs_info based on the fs, add to queue, and return it.
+ * 4) Subsequent accesses to the same disk and partition will get
+ * fs_info from the queue.
+ *
+ * It handles the important stuff to get the MultiFS support working.
+ */
+static struct fs_info *get_fs_info(const char **path)
+{
+ const struct fs_ops **ops;
+ struct fs_info *fsp;
+ struct disk_info diskinfo;
+ struct part_iter *iter = NULL;
+ struct device *dev = NULL;
+ void *private;
+ int blk_shift = -1;
+ uint8_t disk_devno, hdd, partition;
+
+ if (parse_multifs_path(path, &hdd, &partition)) {
+ printf("MultiFS: Syntax invalid: %s\n", *path);
+ return NULL;
+ }
+
+ fsp = get_fs(hdd, partition - 1);
+ if (fsp)
+ return fsp;
+
+ fsp = malloc(sizeof(struct fs_info));
+ if (!fsp)
+ return NULL;
+
+ disk_devno = DISK_ID_OFFSET + hdd;
+ if (disk_get_params(disk_devno, &diskinfo))
+ goto bail;
+
+ if (find_partition(&iter, &diskinfo, partition)) {
+ printf("MultiFS: Failed to get disk/partition: %s\n", *path);
+ goto bail;
+ }
+ private = get_private(disk_devno, iter->abs_lba, diskinfo.head,
+ diskinfo.spt);
+
+ /* Default name for the root directory */
+ fsp->cwd_name[0] = '/';
+ fsp->cwd_name[1] = '\0';
+
+ ops = p_ops;
+ while ((blk_shift < 0) && *ops) {
+ /* set up the fs stucture */
+ fsp->fs_ops = *ops;
+
+ /*
+ * This boldly assumes that we don't mix FS_NODEV filesystems
+ * with FS_DEV filesystems...
+ */
+ if (fsp->fs_ops->fs_flags & FS_NODEV) {
+ fsp->fs_dev = NULL;
+ } else {
+ if (!dev) {
+ dev = device_init(private);
+ if (!dev)
+ goto bail;
+ }
+ fsp->fs_dev = dev;
+ }
+ /* invoke the fs-specific init code */
+ blk_shift = fsp->fs_ops->fs_init(fsp);
+ ops++;
+ }
+ if (blk_shift < 0) {
+ printf("MultiFS: No valid file system found!\n");
+ goto free_dev;
+ }
+
+ /* add fs_info into hdd queue */
+ if (add_fs(fsp, hdd, partition - 1))
+ goto free_dev;
+
+ /* initialize the cache */
+ if (fsp->fs_dev && fsp->fs_dev->cache_data)
+ cache_init(fsp->fs_dev, blk_shift);
+
+ /* start out in the root directory */
+ if (fsp->fs_ops->iget_root) {
+ fsp->root = fsp->fs_ops->iget_root(fsp);
+ fsp->cwd = get_inode(fsp->root);
+ }
+
+ return fsp;
+free_dev:
+ free(dev->disk);
+ free(dev->cache_data);
+ free(dev);
+bail:
+ free(fsp);
+ return NULL;
+}
+
+/*
+ * Initialize MultiFS support
+ */
+void init_multifs(void)
+{
+ enable_multifs(&get_fs_info);
+ dprintf("MultiFS support was enabled successfully!\n");
+}
diff --git a/mk/lib.mk b/mk/lib.mk
index c56d3e3..d059ad5 100644
--- a/mk/lib.mk
+++ b/mk/lib.mk
@@ -107,6 +107,7 @@ LIBOTHER_OBJS = \
\
sys/x86_init_fpu.o math/pow.o math/strtod.o \
syslinux/disk.o syslinux/utility.o syslinux/partiter.o \
+ syslinux/multifs_utils.o \
\
syslinux/setup_data.o
--
2.1.0
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