From: Kevin O'Connor <kevin@koconnor.net>
Date: Sat, 7 Dec 2013 16:46:37 +0000 (-0500)
Subject: floppy: Fix incorrect LBA to CHS translation.
X-Git-Tag: rel-1.7.4~10
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=302a6e82dc9e8c6f1028f98e578336aed07d8f66;p=seabios.git

floppy: Fix incorrect LBA to CHS translation.

The floppy LBA to CHS translation was incorrect for the last sector of
a given cylinder.  This wasn't a problem under QEMU as it came to the
same results anyway, but it causes errors of real floppy controllers.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---

diff --git a/src/hw/floppy.c b/src/hw/floppy.c
index d43b489..c5118ec 100644
--- a/src/hw/floppy.c
+++ b/src/hw/floppy.c
@@ -496,11 +496,10 @@ static struct chs_s
 lba2chs(struct disk_op_s *op)
 {
     struct chs_s res = { };
-    u32 lba = op->lba;
 
-    u32 tmp = lba + 1;
+    u32 tmp = op->lba;
     u16 nls = GET_GLOBALFLAT(op->drive_gf->lchs.sector);
-    res.sector = tmp % nls;
+    res.sector = (tmp % nls) + 1;
 
     tmp /= nls;
     u16 nlh = GET_GLOBALFLAT(op->drive_gf->lchs.head);