On 04/23/2013 10:58 AM, Cornelia Huck wrote:
On Mon, 22 Apr 2013 21:18:11 +0200
Alexander Graf<ag...@suse.de> wrote:
This C file is the main driving piece of the s390 ccw firmware. It
provides a search for a workable block device, sets it as the default
to boot off of and boots from it.
Signed-off-by: Alexander Graf<ag...@suse.de>
---
pc-bios/s390-ccw/main.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 56 insertions(+), 0 deletions(-)
create mode 100644 pc-bios/s390-ccw/main.c
diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
new file mode 100644
index 0000000..0913aac
--- /dev/null
+++ b/pc-bios/s390-ccw/main.c
@@ -0,0 +1,56 @@
+/*
+ * S390 virtio-ccw loading program
+ *
+ * Copyright (c) 2013 Alexander Graf<ag...@suse.de>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "s390-ccw.h"
+
+struct subchannel_id blk_schid;
+char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
+
+void virtio_panic(const char *string)
+{
+ sclp_print(string);
+ while (1) { }
+}
+
+static void virtio_setup(void)
+{
+ struct irb irb;
+ int i;
+ int r;
+ bool found = false;
+
+ blk_schid.one = 1;
+
+ for (i = 0; i< 0x10000; i++) {
+ blk_schid.sch_no = i;
+ r = tsch(blk_schid,&irb);
You want to do a stsch() loop here, not a tsch() loop :)
What does stsch buy us over tsch?
As a bonus, you can exit the loop on cc == 3.
r = stsch(blk_schid,&schib);
if (r == 3) {
break;
}
+ if (r != 3) {
if (schib.pmcw.dnv) {
+ if (virtio_is_blk(blk_schid)) {
+ found = true;
+ break;
+ }
+ }
+ }
+
+ if (!found) {
+ virtio_panic("No virtio-blk device found!\n");
+ }
+
+ virtio_setup_block(blk_schid);
The virtio_is_blk() and virtio_setup_block() functions should go into a
preceding patch, no?
The code doesn't get compiled before the end of the series anyway, so
ordering might be slightly off :)
Alex