pc: Make -no-fd-bootchk stick across boot order changes

Option -no-fd-bootchk asks the BIOS to attempt booting from a floppy
even when the boot sector signature isn't there, by setting a bit in
RTC CMOS.  It was added back in 2006 (commit 52ca8d6a).

Two years later, commit 0ecdffbb added monitor command boot_set.
Implemented by new function pc_boot_set().  It unconditionally clears
the floppy signature bit in CMOS.

Commit e0f084bf added -boot option once to automatically change the
boot order on first reset.  Reuses pc_boot_set(), thus also clears the
floppy signature bit.  Commit d9346e81 took care to preserve this
behavior.

Thus, -no-fd-bootchk applies to any number of boots.  Except it
applies just to the first boot with -boot once, and never after
boot_set.  Weird.  Make it stick instead: set the bit according to
-no-fd-bootchk in pc_boot_set().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1371208516-7857-6-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index e0fbb860ed..5e8f143bc2 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -266,7 +266,7 @@ static int boot_device2nibble(char boot_device)
     return 0;
 }
 
-static int set_boot_dev(ISADevice *s, const char *boot_device, int fd_bootchk)
+static int set_boot_dev(ISADevice *s, const char *boot_device)
 {
 #define PC_MAX_BOOT_DEVICES 3
     int nbds, bds[3] = { 0, };
@@ -292,7 +292,7 @@ static int set_boot_dev(ISADevice *s, const char *boot_device, int fd_bootchk)
 
 static int pc_boot_set(void *opaque, const char *boot_device)
 {
-    return set_boot_dev(opaque, boot_device, 0);
+    return set_boot_dev(opaque, boot_device);
 }
 
 typedef struct pc_cmos_init_late_arg {
@@ -407,8 +407,7 @@ void pc_cmos_init(ram_addr_t ram_size, ram_addr_t above_4g_mem_size,
     cpu_hotplug_cb.cpu_added_notifier.notify = rtc_notify_cpu_added;
     qemu_register_cpu_added_notifier(&cpu_hotplug_cb.cpu_added_notifier);
 
-    /* set boot devices, and disable floppy signature check if requested */
-    if (set_boot_dev(s, boot_device, fd_bootchk)) {
+    if (set_boot_dev(s, boot_device)) {
         exit(1);
     }