Make nic option rom loading less painful.

The code how it is today, is totally painful to read and keep.
To begin with, the code is duplicated with the option rom loading
code that linux_boot and vga are already using.

This patch introduces a "bootable" state in NICInfo structure,
that we can use to keep track of whether or not a given nic should
be bootable, avoiding the introduction of yet another global state.

With that in hands, we move the code in vl.c to hw/pc.c, and use
the already existing infra structure to load those option roms.

Error checking code suggested by Mark McLoughlin

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/pc.c b/hw/pc.c
index 143b697..3521d29 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -977,8 +977,23 @@
     }
 
     for (i = 0; i < nb_option_roms; i++) {
-        oprom_area_size += load_option_rom(option_rom[i],
-                                           0xc0000 + oprom_area_size, 0xe0000);
+        oprom_area_size += load_option_rom(option_rom[i], 0xc0000 + oprom_area_size,
+                                           0xe0000);
+    }
+
+    for (i = 0; i < nb_nics; i++) {
+        char nic_oprom[1024];
+        const char *model = nd_table[i].model;
+
+        if (!nd_table[i].bootable)
+            continue;
+
+        if (model == NULL)
+            model = "ne2k_pci";
+        snprintf(nic_oprom, sizeof(nic_oprom), "pxe-%s.bin", model);
+
+        oprom_area_size += load_option_rom(nic_oprom, 0xc0000 + oprom_area_size,
+                                           0xe0000);
     }
 
     /* map all the bios at the top of memory */
diff --git a/net.c b/net.c
index af9de73..c83999b 100644
--- a/net.c
+++ b/net.c
@@ -2457,6 +2457,26 @@
     return net_client_init(NULL, device, p);
 }
 
+void net_set_boot_mask(int net_boot_mask)
+{
+    int i;
+
+    /* Only the first four NICs may be bootable */
+    net_boot_mask = net_boot_mask & 0xF;
+
+    for (i = 0; i < nb_nics; i++) {
+        if (net_boot_mask & (1 << i)) {
+            nd_table[i].bootable = 1;
+            net_boot_mask &= ~(1 << i);
+        }
+    }
+
+    if (net_boot_mask) {
+        fprintf(stderr, "Cannot boot from non-existent NIC\n");
+        exit(1);
+    }
+}
+
 void do_info_network(Monitor *mon)
 {
     VLANState *vlan;
diff --git a/net.h b/net.h
index 89e7706..a9abf63 100644
--- a/net.h
+++ b/net.h
@@ -91,6 +91,7 @@
     VLANState *vlan;
     void *private;
     int used;
+    int bootable;
 };
 
 extern int nb_nics;
@@ -126,6 +127,7 @@
 void net_cleanup(void);
 int slirp_is_inited(void);
 void net_client_check(void);
+void net_set_boot_mask(int boot_mask);
 void net_host_device_add(Monitor *mon, const char *device, const char *opts);
 void net_host_device_remove(Monitor *mon, int vlan_id, const char *device);
 
diff --git a/vl.c b/vl.c
index 3242c23..2d9f04e 100644
--- a/vl.c
+++ b/vl.c
@@ -5801,7 +5801,6 @@
         exit(1);
     }
     linux_boot = (kernel_filename != NULL);
-    net_boot = (boot_devices_bitmap >> ('n' - 'a')) & 0xF;
 
     if (!linux_boot && *kernel_cmdline != '\0') {
         fprintf(stderr, "-append only allowed with -kernel option\n");
@@ -5849,41 +5848,11 @@
         if (net_client_parse(net_clients[i]) < 0)
             exit(1);
     }
-    net_client_check();
 
-#ifdef TARGET_I386
-    /* XXX: this should be moved in the PC machine instantiation code */
-    if (net_boot != 0) {
-        int netroms = 0;
-	for (i = 0; i < nb_nics && i < 4; i++) {
-	    const char *model = nd_table[i].model;
-	    char buf[1024];
-            char *filename;
-            if (net_boot & (1 << i)) {
-                if (model == NULL)
-                    model = "ne2k_pci";
-                snprintf(buf, sizeof(buf), "pxe-%s.bin", model);
-                filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, buf);
-                if (filename && get_image_size(filename) > 0) {
-                    if (nb_option_roms >= MAX_OPTION_ROMS) {
-                        fprintf(stderr, "Too many option ROMs\n");
-                        exit(1);
-                    }
-                    option_rom[nb_option_roms] = qemu_strdup(buf);
-                    nb_option_roms++;
-                    netroms++;
-                }
-                if (filename) {
-                    qemu_free(filename);
-                }
-            }
-	}
-	if (netroms == 0) {
-	    fprintf(stderr, "No valid PXE rom found for network device\n");
-	    exit(1);
-	}
-    }
-#endif
+    net_boot = (boot_devices_bitmap >> ('n' - 'a')) & 0xF;
+    net_set_boot_mask(net_boot);
+
+    net_client_check();
 
     /* init the bluetooth world */
     for (i = 0; i < nb_bt_opts; i++)