+// read/write count blocks from a harddrive.
+static int
+ahci_disk_readwrite(struct disk_op_s *op, int iswrite)
+{
+ // if caller's buffer is word aligned, use it directly
+ if (((u32) op->buf_fl & 1) == 0)
+ return ahci_disk_readwrite_aligned(op, iswrite);
+
+ // Use a word aligned buffer for AHCI I/O
+ int rc;
+ struct disk_op_s localop = *op;
+ u8 *alignedbuf_fl = GET_GLOBAL(ahci_buf_fl);
+ u8 *position = op->buf_fl;
+
+ localop.buf_fl = alignedbuf_fl;
+ localop.count = 1;
+
+ if (iswrite) {
+ u16 block;
+ for (block = 0; block < op->count; block++) {
+ memcpy_fl (alignedbuf_fl, position, DISK_SECTOR_SIZE);
+ rc = ahci_disk_readwrite_aligned (&localop, 1);
+ if (rc)
+ return rc;
+ position += DISK_SECTOR_SIZE;
+ localop.lba++;
+ }
+ } else { // read
+ u16 block;
+ for (block = 0; block < op->count; block++) {
+ rc = ahci_disk_readwrite_aligned (&localop, 0);
+ if (rc)
+ return rc;
+ memcpy_fl (position, alignedbuf_fl, DISK_SECTOR_SIZE);
+ position += DISK_SECTOR_SIZE;
+ localop.lba++;
+ }
+ }
+ return DISK_RET_SUCCESS;
+}
+