$NetBSD: patch-di,v 1.1 2008/03/03 16:45:27 hannken Exp $

--- libfsimage/common/fsimage_grub.c.orig	2008-01-31 11:06:54.000000000 +0100
+++ libfsimage/common/fsimage_grub.c	2008-03-01 18:59:27.000000000 +0100
@@ -204,6 +204,45 @@ int
 fsig_devread(fsi_file_t *ffi, unsigned int sector, unsigned int offset,
     unsigned int bufsize, char *buf)
 {
+#ifdef __NetBSD__
+	off_t off;
+	ssize_t ret;
+	int n, r;
+	char tmp[512];
+
+	off = ffi->ff_fsi->f_off + ((off_t)sector * 512) + offset;
+
+	/*
+	 * On NetBSD reads from a raw disk must be sector-aligned.
+	 * Split the read into up to three parts to meet this requirement.
+	 */
+
+	if ((n = (off & 511)) > 0) {
+		if ((r = 512 - n) > bufsize)
+			r = bufsize;
+		if ((ret = pread(ffi->ff_fsi->f_fd, tmp, 512, off - n)) < n + r)
+			return (0);
+		bcopy(tmp + n, buf, r);
+		buf += r;
+		bufsize -= r;
+		off += r;
+	}
+
+	if ((n = (bufsize & ~511)) > 0) {
+		if ((ret = pread(ffi->ff_fsi->f_fd, buf, n, off)) < n)
+			return (0);
+		buf += n;
+		bufsize -= n;
+		off += n;
+	}
+	if (bufsize > 0) {
+		if ((ret = pread(ffi->ff_fsi->f_fd, tmp, 512, off)) < bufsize)
+			return (0);
+		bcopy(tmp, buf, bufsize);
+	}
+
+	return (1);
+#else /* __NetBSD__ */
 	uint64_t off = ffi->ff_fsi->f_off + ((uint64_t)sector * 512) + offset;
 	ssize_t bytes_read = 0;
 
@@ -220,6 +259,7 @@ fsig_devread(fsi_file_t *ffi, unsigned i
 	}
 
 	return (1);
+#endif /* __NetBSD__ */
 }
 
 int