chain.c32, libcom32: Move read_sectors() as disk_read_sectors()

Moving portions of chain.c32 into libcom32.

Signed-off-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>

diff --git a/com32/include/syslinux/disk.h b/com32/include/syslinux/disk.h
index 51af728..b6cdef0 100644 (file)
--- a/com32/include/syslinux/disk.h
+++ b/com32/include/syslinux/disk.h
@@ -37,6 +37,7 @@
 #define _SYSLINUX_DISK_H
 
 #include <com32.h>
+#include <stdint.h>
 
 #define SECTOR 512             /* bytes/sector */
 
@@ -58,5 +59,7 @@ struct disk_ebios_dapa {
 
 extern int disk_int13_retry(const com32sys_t * inreg, com32sys_t * outreg);
 extern int disk_get_params(int disk, struct disk_info *diskinfo);
+extern void *disk_read_sectors(struct disk_info *diskinfo, uint64_t lba,
+                              uint8_t count);
 
 #endif /* _SYSLINUX_DISK_H */

diff --git a/com32/lib/syslinux/disk.c b/com32/lib/syslinux/disk.c
index 0fd3548..f13122e 100644 (file)
--- a/com32/lib/syslinux/disk.c
+++ b/com32/lib/syslinux/disk.c
@@ -33,6 +33,8 @@
  * Deal with disks and partitions
  */
 
+#include <stdlib.h>
+#include <string.h>
 #include <syslinux/disk.h>
 
 /**
@@ -105,3 +107,79 @@ int disk_get_params(int disk, struct disk_info *diskinfo)
 
     return 0;
 }
+
+/**
+ * Get a disk block and return a malloc'd buffer.
+ *
+ * @v diskinfo                 The disk drive to read from
+ * @v lba                      The logical block address to begin reading at
+ * @v count                    The number of sectors to read
+ * @ret data                   An allocated buffer with the read data
+ *
+ * Uses the disk number and information from diskinfo.  Read count sectors
+ * from drive, starting at lba.  Return a new buffer, or NULL upon failure.
+ */
+void *disk_read_sectors(struct disk_info *diskinfo, uint64_t lba, uint8_t count)
+{
+    com32sys_t inreg;
+    struct disk_ebios_dapa *dapa = __com32.cs_bounce;
+    void *buf = (char *)__com32.cs_bounce + SECTOR;
+    void *data;
+
+    if (!count)
+       /* Silly */
+       return NULL;
+
+    memset(&inreg, 0, sizeof inreg);
+
+    if (diskinfo->ebios) {
+       dapa->len = sizeof(*dapa);
+       dapa->count = count;
+       dapa->off = OFFS(buf);
+       dapa->seg = SEG(buf);
+       dapa->lba = lba;
+
+       inreg.esi.w[0] = OFFS(dapa);
+       inreg.ds = SEG(dapa);
+       inreg.edx.b[0] = diskinfo->disk;
+       inreg.eax.b[1] = 0x42;  /* Extended read */
+    } else {
+       unsigned int c, h, s, t;
+
+       if (!diskinfo->cbios) {
+           /* We failed to get the geometry */
+
+           if (lba)
+               return NULL;    /* Can only read MBR */
+
+           s = 1;
+           h = 0;
+           c = 0;
+       } else {
+           s = (lba % diskinfo->sect) + 1;
+           t = lba / diskinfo->sect;   /* Track = head*cyl */
+           h = t % diskinfo->head;
+           c = t / diskinfo->head;
+       }
+
+       if (s > 63 || h > 256 || c > 1023)
+           return NULL;
+
+       inreg.eax.b[0] = count;
+       inreg.eax.b[1] = 0x02;  /* Read */
+       inreg.ecx.b[1] = c & 0xff;
+       inreg.ecx.b[0] = s + (c >> 6);
+       inreg.edx.b[1] = h;
+       inreg.edx.b[0] = diskinfo->disk;
+       inreg.ebx.w[0] = OFFS(buf);
+       inreg.es = SEG(buf);
+    }
+
+    if (disk_int13_retry(&inreg, NULL))
+       return NULL;
+
+    data = malloc(count * SECTOR);
+    if (data)
+       memcpy(data, buf, count * SECTOR);
+    return data;
+}

diff --git a/com32/modules/chain.c b/com32/modules/chain.c
index ea04b8b..0ff1ea1 100644 (file)
--- a/com32/modules/chain.c
+++ b/com32/modules/chain.c
@@ -147,76 +147,6 @@ static inline void error(const char *msg)
 
 static struct disk_info diskinfo;
 
-/*
- * Get a disk block and return a malloc'd buffer.
- * Uses the disk number and information from diskinfo.
- */
-/* Read count sectors from drive, starting at lba.  Return a new buffer */
-static void *read_sectors(uint64_t lba, uint8_t count)
-{
-    com32sys_t inreg;
-    struct disk_ebios_dapa *dapa = __com32.cs_bounce;
-    void *buf = (char *)__com32.cs_bounce + SECTOR;
-    void *data;
-
-    if (!count)
-       /* Silly */
-       return NULL;
-
-    memset(&inreg, 0, sizeof inreg);
-
-    if (diskinfo.ebios) {
-       dapa->len = sizeof(*dapa);
-       dapa->count = count;
-       dapa->off = OFFS(buf);
-       dapa->seg = SEG(buf);
-       dapa->lba = lba;
-
-       inreg.esi.w[0] = OFFS(dapa);
-       inreg.ds = SEG(dapa);
-       inreg.edx.b[0] = diskinfo.disk;
-       inreg.eax.b[1] = 0x42;  /* Extended read */
-    } else {
-       unsigned int c, h, s, t;
-
-       if (!diskinfo.cbios) {
-           /* We failed to get the geometry */
-
-           if (lba)
-               return NULL;    /* Can only read MBR */
-
-           s = 1;
-           h = 0;
-           c = 0;
-       } else {
-           s = (lba % diskinfo.sect) + 1;
-           t = lba / diskinfo.sect;    /* Track = head*cyl */
-           h = t % diskinfo.head;
-           c = t / diskinfo.head;
-       }
-
-       if (s > 63 || h > 256 || c > 1023)
-           return NULL;
-
-       inreg.eax.b[0] = count;
-       inreg.eax.b[1] = 0x02;  /* Read */
-       inreg.ecx.b[1] = c & 0xff;
-       inreg.ecx.b[0] = s + (c >> 6);
-       inreg.edx.b[1] = h;
-       inreg.edx.b[0] = diskinfo.disk;
-       inreg.ebx.w[0] = OFFS(buf);
-       inreg.es = SEG(buf);
-    }
-
-    if (disk_int13_retry(&inreg, NULL))
-       return NULL;
-
-    data = malloc(count * SECTOR);
-    if (data)
-       memcpy(data, buf, count * SECTOR);
-    return data;
-}
-
 static int write_sector(unsigned int lba, const void *data)
 {
     com32sys_t inreg;
@@ -282,7 +212,7 @@ static int write_verify_sector(unsigned int lba, const void *buf)
     rv = write_sector(lba, buf);
     if (rv)
        return rv;              /* Write failure */
-    rb = read_sectors(lba, 1);
+    rb = disk_read_sectors(&diskinfo, lba, 1);
     if (!rb)
        return -1;              /* Readback failure */
     rv = memcmp(buf, rb, SECTOR);
@@ -364,7 +294,7 @@ static int find_disk(uint32_t mbr_sig)
     for (drive = 0x80; drive <= 0xff; drive++) {
        if (disk_get_params(drive, &diskinfo))
            continue;           /* Drive doesn't exist */
-       if (!(mbr = read_sectors(0, 1)))
+       if (!(mbr = disk_read_sectors(&diskinfo, 0, 1)))
            continue;           /* Cannot read sector */
        is_me = (mbr->disk_sig == mbr_sig);
        free(mbr);
@@ -453,7 +383,7 @@ static struct disk_part_iter *next_ebr_part(struct disk_part_iter *part)
     /* Load next EBR */
     ebr_lba = ebr_table->start_lba + part->private.ebr.lba_extended;
     free(part->block);
-    part->block = read_sectors(ebr_lba, 1);
+    part->block = disk_read_sectors(&diskinfo, ebr_lba, 1);
     if (!part->block) {
        error("Could not load EBR!\n");
        goto err_ebr;
@@ -813,7 +743,7 @@ static struct disk_part_iter *get_first_partition(struct disk_part_iter *part)
        goto err_alloc_iter;
     }
     /* Read MBR */
-    part->block = read_sectors(0, 2);
+    part->block = disk_read_sectors(&diskinfo, 0, 2);
     if (!part->block) {
        error("Could not read two sectors!\n");
        goto err_read_mbr;
@@ -851,9 +781,10 @@ static struct disk_part_iter *get_first_partition(struct disk_part_iter *part)
        /* Load the partition table */
        free(part->block);
        part->block =
-           read_sectors(lba_table,
-                        ((part->private.gpt.size * part->private.gpt.parts) +
-                         SECTOR - 1) / SECTOR);
+           disk_read_sectors(&diskinfo, lba_table,
+                             ((part->private.gpt.size *
+                               part->private.gpt.parts) + SECTOR -
+                              1) / SECTOR);
        if (!part->block) {
            error("Could not read GPT partition list!\n");
            goto err_gpt_table;
@@ -894,7 +825,7 @@ static int find_by_guid(const struct guid *gpt_guid,
     for (drive = 0x80; drive <= 0xff; drive++) {
        if (disk_get_params(drive, &diskinfo))
            continue;           /* Drive doesn't exist */
-       if (!(header = read_sectors(1, 1)))
+       if (!(header = disk_read_sectors(&diskinfo, 1, 1)))
            continue;           /* Cannot read sector */
        if (memcmp(&header->sig, gpt_sig_magic, sizeof(gpt_sig_magic))) {
            /* Not a GPT disk */
@@ -1387,7 +1318,7 @@ int main(int argc, char *argv[])
     }
 
     /* Get MBR */
-    if (!(mbr = read_sectors(0, 1))) {
+    if (!(mbr = disk_read_sectors(&diskinfo, 0, 1))) {
        error("Cannot read Master Boot Record or sector 0\n");
        goto bail;
     }
@@ -1621,7 +1552,10 @@ int main(int argc, char *argv[])
        /* Actually read the boot sector */
        if (!cur_part) {
            data[ndata].data = mbr;
-       } else if (!(data[ndata].data = read_sectors(cur_part->lba_data, 1))) {
+       } else
+           if (!
+               (data[ndata].data =
+                disk_read_sectors(&diskinfo, cur_part->lba_data, 1))) {
            error("Cannot read boot sector\n");
            goto bail;
        }