Fix bug - bios writes must be enabled before max PCI bus detected.

The max pci bus is stored in the bios segment, so it must be writable.
So, use a default max size (1 pci bus) for the initial write enable
    device scan and then do the full max bus check after write is
    enabled.

2 files changed, 3 insertions, 3 deletions

diff --git a/src/pci.c b/src/pci.c
index f586886..91a7ca5 100644
--- a/src/pci.c
+++ b/src/pci.c
@@ -49,7 +49,7 @@ u8 pci_config_readb(u16 bdf, u32 addr)
 }
 
 #if MODE16
-int MaxBDF VISIBLE16;
+int MaxBDF VISIBLE16 = 0x0100;
 #endif
 
 // Find the maximum bus number.
diff --git a/src/post.c b/src/post.c
index 6f407d9..03049ee 100644
--- a/src/post.c
+++ b/src/post.c
@@ -195,6 +195,8 @@ post()
     timer_setup();
     mathcp_setup();
 
+    pci_bus_setup();
+
     memmap_setup();
     ram_probe();
 
@@ -276,8 +278,6 @@ _start()
     debug_serial_setup();
     dprintf(1, "Start bios\n");
 
-    pci_bus_setup();
-
     // Setup for .bss and .data sections
     make_bios_writable();
     clear_bss();