Set irq0 override in fw_cfg, informing the BIOS that QEMU expects
override on irq0. This matches qemu-kvm, and will help sharing a
single BIOS binary.

Signed-off-by: Jes Sorensen <address@hidden>

---
 hw/pc.c  |    2 ++
 sysemu.h |    1 +
 vl.c     |    1 +
 3 files changed, 4 insertions(+)

Index: qemu/hw/pc.c
===================================================================
--- qemu.orig/hw/pc.c
+++ qemu/hw/pc.c
@@ -54,6 +54,7 @@
 #define BIOS_CFG_IOPORT 0x510
 #define FW_CFG_ACPI_TABLES (FW_CFG_ARCH_LOCAL + 0)
 #define FW_CFG_SMBIOS_ENTRIES (FW_CFG_ARCH_LOCAL + 1)
+#define FW_CFG_IRQ0_OVERRIDE (FW_CFG_ARCH_LOCAL + 2)
 
 #define MAX_IDE_BUS 2
 
@@ -476,6 +477,7 @@ static void *bochs_bios_init(void)
     fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
     fw_cfg_add_bytes(fw_cfg, FW_CFG_ACPI_TABLES, (uint8_t *)acpi_tables,
                      acpi_tables_len);
+    fw_cfg_add_bytes(fw_cfg, FW_CFG_IRQ0_OVERRIDE, &irq0override, 1);
 
     smbios_table = smbios_get_table(&smbios_len);
     if (smbios_table)
Index: qemu/sysemu.h
===================================================================
--- qemu.orig/sysemu.h
+++ qemu/sysemu.h
@@ -113,6 +113,7 @@ extern int xenfb_enabled;
 extern int graphic_width;
 extern int graphic_height;
 extern int graphic_depth;
+extern uint8_t irq0override;
 extern DisplayType display_type;
 extern const char *keyboard_layout;
 extern int win2k_install_hack;
Index: qemu/vl.c
===================================================================
--- qemu.orig/vl.c
+++ qemu/vl.c
@@ -229,6 +229,7 @@ int no_reboot = 0;
 int no_shutdown = 0;
 int cursor_hide = 1;
 int graphic_rotate = 0;
+uint8_t irq0override = 1;
 #ifndef _WIN32
 int daemonize = 0;
 #endif