hvmloader: Move option ROM loading into a separate optionnal file

Make load_rom field in struct bios_config an optionnal callback rather
than a boolean value. It allow BIOS specific code to implement it's
own option ROM loading methods.

Facilities to scan PCI devices, extract an deploy ROMs are moved into
a separate file that can be compiled optionnaly.

Signed-off-by: Julian Pidancet <julian.pidancet@gmail.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

7 files changed, 259 insertions, 228 deletions

diff --git a/tools/firmware/hvmloader/Makefile b/tools/firmware/hvmloader/Makefile
index 1ea32dbd27..5a5ee41e79 100644
--- a/tools/firmware/hvmloader/Makefile
+++ b/tools/firmware/hvmloader/Makefile
@@ -39,7 +39,7 @@ CIRRUSVGA_DEBUG ?= n
 
 ROMBIOS_DIR := ../rombios
 ifneq ($(ROMBIOS_DIR),)
-OBJS += 32bitbios_support.o rombios.o
+OBJS += optionroms.o 32bitbios_support.o rombios.o
 CFLAGS += -DENABLE_ROMBIOS
 ROMBIOS_ROM := $(ROMBIOS_DIR)/BIOS-bochs-latest
 endif
diff --git a/tools/firmware/hvmloader/config.h b/tools/firmware/hvmloader/config.h
index 9cac9c1000..1f80263676 100644
--- a/tools/firmware/hvmloader/config.h
+++ b/tools/firmware/hvmloader/config.h
@@ -18,8 +18,7 @@ struct bios_config {
     unsigned int bios_address;
 
     /* ROMS */
-    int load_roms;
-    unsigned int optionrom_start, optionrom_end;
+    void (*load_roms)(void);
 
     void (*bios_load)(const struct bios_config *config);
 
diff --git a/tools/firmware/hvmloader/hvmloader.c b/tools/firmware/hvmloader/hvmloader.c
index f120ffea1b..ad501893d5 100644
--- a/tools/firmware/hvmloader/hvmloader.c
+++ b/tools/firmware/hvmloader/hvmloader.c
@@ -24,16 +24,11 @@
 #include "hypercall.h"
 #include "config.h"
 #include "pci_regs.h"
-#include "option_rom.h"
 #include "apic_regs.h"
 #include "acpi/acpi2_0.h"
 #include <xen/version.h>
 #include <xen/hvm/params.h>
 
-#define ROM_INCLUDE_VGABIOS
-#define ROM_INCLUDE_ETHERBOOT
-#include "roms.inc"
-
 asm (
     "    .text                       \n"
     "    .globl _start               \n"
@@ -147,169 +142,6 @@ static void init_hypercalls(void)
     printf("Detected Xen v%u.%u%s\n", eax >> 16, eax & 0xffff, extraversion);
 }
 
-/*
- * Scan the list of Option ROMs at @roms for one which supports 
- * PCI (@vendor_id, @device_id) found at slot @devfn. If one is found,
- * copy it to @dest and return its size rounded up to a multiple 2kB. This
- * function will not copy ROMs beyond address option_rom_end.
- */
-#define round_option_rom(x) (((x) + 2047) & ~2047)
-static int scan_option_rom(
-    unsigned int option_rom_end,
-    uint8_t devfn, uint16_t vendor_id, uint16_t device_id,
-    void *roms, uint32_t dest)
-{
-    struct option_rom_header *rom;
-    struct option_rom_pnp_header *pnph;
-    struct option_rom_pci_header *pcih;
-    uint8_t csum;
-    int i;
-
-    static uint32_t orom_ids[64];
-    static int nr_roms;
-
-    /* Avoid duplicate ROMs. */
-    for ( i = 0; i < nr_roms; i++ )
-        if ( orom_ids[i] == (vendor_id | ((uint32_t)device_id << 16)) )
-            return 0;
-
-    rom = roms;
-    for ( ; ; )
-    {
-        /* Invalid signature means we're out of option ROMs. */
-        if ( strncmp((char *)rom->signature, "\x55\xaa", 2) ||
-             (rom->rom_size == 0) )
-            break;
-
-        /* Invalid checksum means we're out of option ROMs. */
-        csum = 0;
-        for ( i = 0; i < (rom->rom_size * 512); i++ )
-            csum += ((uint8_t *)rom)[i];
-        if ( csum != 0 )
-            break;
-
-        /* Check the PCI PnP header (if any) for a match. */
-        pcih = (struct option_rom_pci_header *)
-            ((char *)rom + rom->pci_header_offset);
-        if ( (rom->pci_header_offset != 0) &&
-             !strncmp((char *)pcih->signature, "PCIR", 4) &&
-             (pcih->vendor_id == vendor_id) &&
-             (pcih->device_id == device_id) )
-            goto found;
-
-        rom = (struct option_rom_header *)
-            ((char *)rom + rom->rom_size * 512);
-    }
-
-    return 0;
-
- found:
-    /* Find the PnP expansion header (if any). */
-    pnph = ((rom->expansion_header_offset != 0)
-            ? ((struct option_rom_pnp_header *)
-               ((char *)rom + rom->expansion_header_offset))
-            : ((struct option_rom_pnp_header *)NULL));
-    while ( (pnph != NULL) && strncmp((char *)pnph->signature, "$PnP", 4) )
-        pnph = ((pnph->next_header_offset != 0)
-                ? ((struct option_rom_pnp_header *)
-                   ((char *)rom + pnph->next_header_offset))
-                : ((struct option_rom_pnp_header *)NULL));
-
-    printf("Loading PCI Option ROM ...\n");
-    if ( (pnph != NULL) && (pnph->manufacturer_name_offset != 0) )
-        printf(" - Manufacturer: %s\n",
-               (char *)rom + pnph->manufacturer_name_offset);
-    if ( (pnph != NULL) && (pnph->product_name_offset != 0) )
-        printf(" - Product name: %s\n",
-               (char *)rom + pnph->product_name_offset);
-
-    if ( (dest + rom->rom_size * 512 + 1) > option_rom_end )
-    {
-        printf("Option ROM size %x exceeds available space\n",
-               rom->rom_size * 512);
-        return 0;
-    }
-
-    orom_ids[nr_roms++] = vendor_id | ((uint32_t)device_id << 16);
-    memcpy((void *)dest, rom, rom->rom_size * 512);
-    *(uint8_t *)(dest + rom->rom_size * 512) = devfn;
-    return round_option_rom(rom->rom_size * 512 + 1);
-}
-
-/*
- * Scan the PCI bus for the first NIC supported by etherboot, and copy
- * the corresponding rom data to *copy_rom_dest. Returns the length of the
- * selected rom, or 0 if no NIC found.
- */
-static int scan_etherboot_nic(unsigned int option_rom_end,
-                              uint32_t copy_rom_dest)
-{
-    uint16_t class, vendor_id, device_id, devfn;
-    int rom_size = 0;
-
-    for ( devfn = 0; (devfn < 256) && !rom_size; devfn++ )
-    {
-        class     = pci_readw(devfn, PCI_CLASS_DEVICE);
-        vendor_id = pci_readw(devfn, PCI_VENDOR_ID);
-        device_id = pci_readw(devfn, PCI_DEVICE_ID);
-
-        /* We're only interested in NICs. */
-        if ( (vendor_id != 0xffff) &&
-             (device_id != 0xffff) &&
-             (class == 0x0200) )
-            rom_size = scan_option_rom(
-                option_rom_end,
-                devfn, vendor_id, device_id, etherboot, copy_rom_dest);
-    }
-
-    return rom_size;
-}
-
-/*
- * Scan the PCI bus for the devices that have an option ROM, and copy
- * the corresponding rom data to rom_phys_addr.
- */
-static int pci_load_option_roms(unsigned int option_rom_end,
-                                uint32_t rom_base_addr)
-{
-    uint32_t option_rom_addr, rom_phys_addr = rom_base_addr;
-    uint16_t vendor_id, device_id, devfn, class;
-
-    for ( devfn = 0; devfn < 256; devfn++ )
-    {
-        class     = pci_readb(devfn, PCI_CLASS_DEVICE + 1);
-        vendor_id = pci_readw(devfn, PCI_VENDOR_ID);
-        device_id = pci_readw(devfn, PCI_DEVICE_ID);
-
-        if ( (vendor_id == 0xffff) && (device_id == 0xffff) )
-            continue;
-
-        /*
-         * Currently only scan options from mass storage devices and serial
-         * bus controller (Fibre Channel included).
-         */
-        if ( (class != 0x1) && (class != 0xc) )
-            continue;
-
-        option_rom_addr = pci_readl(devfn, PCI_ROM_ADDRESS);
-        if ( !option_rom_addr )
-            continue;
-
-        /* Ensure Expansion Bar is enabled before copying */
-        pci_writel(devfn, PCI_ROM_ADDRESS, option_rom_addr | 0x1);
-
-        rom_phys_addr += scan_option_rom(
-            option_rom_end,
-            devfn, vendor_id, device_id,
-            (void *)(option_rom_addr & ~2047), rom_phys_addr);
-
-        /* Restore the default original value of Expansion Bar */
-        pci_writel(devfn, PCI_ROM_ADDRESS, option_rom_addr);
-    }
-
-    return rom_phys_addr - rom_base_addr;
-}
-
 /* Replace possibly erroneous memory-size CMOS fields with correct values. */
 static void cmos_write_memory_size(void)
 {
@@ -421,8 +253,6 @@ static void acpi_enable_sci(void)
 int main(void)
 {
     const struct bios_config *bios;
-    int option_rom_sz = 0, vgabios_sz = 0, etherboot_sz = 0;
-    uint32_t etherboot_phys_addr = 0, option_rom_phys_addr = 0;
     int acpi_enabled;
 
     /* Initialise hypercall stubs with RET, rendering them no-ops. */
@@ -471,41 +301,7 @@ int main(void)
     }
 
     if ( bios->load_roms )
-    {
-        switch ( virtual_vga )
-        {
-        case VGA_cirrus:
-            printf("Loading Cirrus VGABIOS ...\n");
-            memcpy((void *)VGABIOS_PHYSICAL_ADDRESS,
-                   vgabios_cirrusvga, sizeof(vgabios_cirrusvga));
-            vgabios_sz = round_option_rom(sizeof(vgabios_cirrusvga));
-            break;
-        case VGA_std:
-            printf("Loading Standard VGABIOS ...\n");
-            memcpy((void *)VGABIOS_PHYSICAL_ADDRESS,
-                   vgabios_stdvga, sizeof(vgabios_stdvga));
-            vgabios_sz = round_option_rom(sizeof(vgabios_stdvga));
-            break;
-        case VGA_pt:
-            printf("Loading VGABIOS of passthroughed gfx ...\n");
-            vgabios_sz = round_option_rom(
-                (*(uint8_t *)(VGABIOS_PHYSICAL_ADDRESS+2)) * 512);
-            break;
-        default:
-            printf("No emulated VGA adaptor ...\n");
-            break;
-        }
-
-        etherboot_phys_addr = VGABIOS_PHYSICAL_ADDRESS + vgabios_sz;
-        if ( etherboot_phys_addr < bios->optionrom_start )
-            etherboot_phys_addr = bios->optionrom_start;
-        etherboot_sz = scan_etherboot_nic(bios->optionrom_end,
-                                          etherboot_phys_addr);
-
-        option_rom_phys_addr = etherboot_phys_addr + etherboot_sz;
-        option_rom_sz = pci_load_option_roms(bios->optionrom_end,
-                                             option_rom_phys_addr);
-    }
+        bios->load_roms();
 
     acpi_enabled = !strncmp(xenstore_read("platform/acpi", "1"), "1", 1);
 
@@ -536,18 +332,6 @@ int main(void)
     if ( SCRATCH_PHYSICAL_ADDRESS != scratch_start )
         printf(" %05x-%05lx: Scratch space\n",
                SCRATCH_PHYSICAL_ADDRESS, scratch_start);
-    if ( vgabios_sz )
-        printf(" %05x-%05x: VGA BIOS\n",
-               VGABIOS_PHYSICAL_ADDRESS,
-               VGABIOS_PHYSICAL_ADDRESS + vgabios_sz - 1);
-    if ( etherboot_sz )
-        printf(" %05x-%05x: Etherboot ROM\n",
-               etherboot_phys_addr,
-               etherboot_phys_addr + etherboot_sz - 1);
-    if ( option_rom_sz )
-        printf(" %05x-%05x: PCI Option ROMs\n",
-               option_rom_phys_addr,
-               option_rom_phys_addr + option_rom_sz - 1);
     printf(" %05x-%05x: Main BIOS\n",
            bios->bios_address,
            bios->bios_address + bios->image_size - 1);
diff --git a/tools/firmware/hvmloader/option_rom.h b/tools/firmware/hvmloader/option_rom.h
index f0c7ec482f..1ada3e2209 100644
--- a/tools/firmware/hvmloader/option_rom.h
+++ b/tools/firmware/hvmloader/option_rom.h
@@ -47,6 +47,13 @@ struct option_rom_pci_header {
     uint16_t reserved;
 } __attribute__ ((packed));
 
+#define round_option_rom(x) (((x) + 2047) & ~2047)
+int scan_etherboot_nic(unsigned int option_rom_end,
+                       uint32_t copy_rom_dest,
+                       void *etherboot_rom);
+int pci_load_option_roms(unsigned int option_rom_end,
+                         uint32_t rom_base_addr);
+
 #endif /* __HVMLOADER_OPTION_ROM_H__ */
 
 /*
diff --git a/tools/firmware/hvmloader/optionroms.c b/tools/firmware/hvmloader/optionroms.c
new file mode 100644
index 0000000000..e35aebc58e
--- /dev/null
+++ b/tools/firmware/hvmloader/optionroms.c
@@ -0,0 +1,189 @@
+/*
+ * optionroms.c: Option ROM loading support.
+ *
+ * Leendert van Doorn, leendert@watson.ibm.com
+ * Copyright (c) 2005, International Business Machines Corporation.
+ *
+ * Copyright (c) 2006, Keir Fraser, XenSource Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "config.h"
+#include "option_rom.h"
+#include "util.h"
+#include "pci_regs.h"
+
+/*
+ * Scan the list of Option ROMs at @roms for one which supports 
+ * PCI (@vendor_id, @device_id) found at slot @devfn. If one is found,
+ * copy it to @dest and return its size rounded up to a multiple 2kB. This
+ * function will not copy ROMs beyond address option_rom_end.
+ */
+static int scan_option_rom(
+    unsigned int option_rom_end,
+    uint8_t devfn, uint16_t vendor_id, uint16_t device_id,
+    void *roms, uint32_t dest)
+{
+    struct option_rom_header *rom;
+    struct option_rom_pnp_header *pnph;
+    struct option_rom_pci_header *pcih;
+    uint8_t csum;
+    int i;
+
+    static uint32_t orom_ids[64];
+    static int nr_roms;
+
+    /* Avoid duplicate ROMs. */
+    for ( i = 0; i < nr_roms; i++ )
+        if ( orom_ids[i] == (vendor_id | ((uint32_t)device_id << 16)) )
+            return 0;
+
+    rom = roms;
+    for ( ; ; )
+    {
+        /* Invalid signature means we're out of option ROMs. */
+        if ( strncmp((char *)rom->signature, "\x55\xaa", 2) ||
+             (rom->rom_size == 0) )
+            break;
+
+        /* Invalid checksum means we're out of option ROMs. */
+        csum = 0;
+        for ( i = 0; i < (rom->rom_size * 512); i++ )
+            csum += ((uint8_t *)rom)[i];
+        if ( csum != 0 )
+            break;
+
+        /* Check the PCI PnP header (if any) for a match. */
+        pcih = (struct option_rom_pci_header *)
+            ((char *)rom + rom->pci_header_offset);
+        if ( (rom->pci_header_offset != 0) &&
+             !strncmp((char *)pcih->signature, "PCIR", 4) &&
+             (pcih->vendor_id == vendor_id) &&
+             (pcih->device_id == device_id) )
+            goto found;
+
+        rom = (struct option_rom_header *)
+            ((char *)rom + rom->rom_size * 512);
+    }
+
+    return 0;
+
+ found:
+    /* Find the PnP expansion header (if any). */
+    pnph = ((rom->expansion_header_offset != 0)
+            ? ((struct option_rom_pnp_header *)
+               ((char *)rom + rom->expansion_header_offset))
+            : ((struct option_rom_pnp_header *)NULL));
+    while ( (pnph != NULL) && strncmp((char *)pnph->signature, "$PnP", 4) )
+        pnph = ((pnph->next_header_offset != 0)
+                ? ((struct option_rom_pnp_header *)
+                   ((char *)rom + pnph->next_header_offset))
+                : ((struct option_rom_pnp_header *)NULL));
+
+    printf("Loading PCI Option ROM ...\n");
+    if ( (pnph != NULL) && (pnph->manufacturer_name_offset != 0) )
+        printf(" - Manufacturer: %s\n",
+               (char *)rom + pnph->manufacturer_name_offset);
+    if ( (pnph != NULL) && (pnph->product_name_offset != 0) )
+        printf(" - Product name: %s\n",
+               (char *)rom + pnph->product_name_offset);
+
+    if ( (dest + rom->rom_size * 512 + 1) > option_rom_end )
+    {
+        printf("Option ROM size %x exceeds available space\n",
+               rom->rom_size * 512);
+        return 0;
+    }
+
+    orom_ids[nr_roms++] = vendor_id | ((uint32_t)device_id << 16);
+    memcpy((void *)dest, rom, rom->rom_size * 512);
+    *(uint8_t *)(dest + rom->rom_size * 512) = devfn;
+    return round_option_rom(rom->rom_size * 512 + 1);
+}
+
+/*
+ * Scan the PCI bus for the first NIC supported by etherboot, and copy
+ * the corresponding rom data to *copy_rom_dest. Returns the length of the
+ * selected rom, or 0 if no NIC found.
+ */
+int scan_etherboot_nic(unsigned int option_rom_end,
+                       uint32_t copy_rom_dest,
+                       void *etherboot_rom)
+{
+    uint16_t class, vendor_id, device_id, devfn;
+    int rom_size = 0;
+
+    for ( devfn = 0; (devfn < 256) && !rom_size; devfn++ )
+    {
+        class     = pci_readw(devfn, PCI_CLASS_DEVICE);
+        vendor_id = pci_readw(devfn, PCI_VENDOR_ID);
+        device_id = pci_readw(devfn, PCI_DEVICE_ID);
+
+        /* We're only interested in NICs. */
+        if ( (vendor_id != 0xffff) &&
+             (device_id != 0xffff) &&
+             (class == 0x0200) )
+            rom_size = scan_option_rom(
+                option_rom_end,
+                devfn, vendor_id, device_id, etherboot_rom, copy_rom_dest);
+    }
+
+    return rom_size;
+}
+
+/*
+ * Scan the PCI bus for the devices that have an option ROM, and copy
+ * the corresponding rom data to rom_phys_addr.
+ */
+int pci_load_option_roms(unsigned int option_rom_end,
+                         uint32_t rom_base_addr)
+{
+    uint32_t option_rom_addr, rom_phys_addr = rom_base_addr;
+    uint16_t vendor_id, device_id, devfn, class;
+
+    for ( devfn = 0; devfn < 256; devfn++ )
+    {
+        class     = pci_readb(devfn, PCI_CLASS_DEVICE + 1);
+        vendor_id = pci_readw(devfn, PCI_VENDOR_ID);
+        device_id = pci_readw(devfn, PCI_DEVICE_ID);
+
+        if ( (vendor_id == 0xffff) && (device_id == 0xffff) )
+            continue;
+
+        /*
+         * Currently only scan options from mass storage devices and serial
+         * bus controller (Fibre Channel included).
+         */
+        if ( (class != 0x1) && (class != 0xc) )
+            continue;
+
+        option_rom_addr = pci_readl(devfn, PCI_ROM_ADDRESS);
+        if ( !option_rom_addr )
+            continue;
+
+        /* Ensure Expansion Bar is enabled before copying */
+        pci_writel(devfn, PCI_ROM_ADDRESS, option_rom_addr | 0x1);
+
+        rom_phys_addr += scan_option_rom(
+            option_rom_end,
+            devfn, vendor_id, device_id,
+            (void *)(option_rom_addr & ~2047), rom_phys_addr);
+
+        /* Restore the default original value of Expansion Bar */
+        pci_writel(devfn, PCI_ROM_ADDRESS, option_rom_addr);
+    }
+
+    return rom_phys_addr - rom_base_addr;
+}
diff --git a/tools/firmware/hvmloader/rombios.c b/tools/firmware/hvmloader/rombios.c
index d5831aa9cf..e0d418227f 100644
--- a/tools/firmware/hvmloader/rombios.c
+++ b/tools/firmware/hvmloader/rombios.c
@@ -29,10 +29,13 @@
 #include "pci_regs.h"
 #include "util.h"
 #include "hypercall.h"
+#include "option_rom.h"
 
 #include <xen/hvm/params.h>
 
 #define ROM_INCLUDE_ROMBIOS
+#define ROM_INCLUDE_VGABIOS
+#define ROM_INCLUDE_ETHERBOOT
 #include "roms.inc"
 
 #define ROMBIOS_BEGIN          0x000F0000
@@ -64,6 +67,61 @@ static void rombios_setup_bios_info(void)
     memset(info, 0, sizeof(*info));
 }
 
+static void rombios_load_roms(void)
+{
+    int option_rom_sz = 0, vgabios_sz = 0, etherboot_sz = 0;
+    uint32_t etherboot_phys_addr = 0, option_rom_phys_addr = 0;
+
+    switch ( virtual_vga )
+    {
+    case VGA_cirrus:
+        printf("Loading Cirrus VGABIOS ...\n");
+        memcpy((void *)VGABIOS_PHYSICAL_ADDRESS,
+               vgabios_cirrusvga, sizeof(vgabios_cirrusvga));
+        vgabios_sz = round_option_rom(sizeof(vgabios_cirrusvga));
+        break;
+    case VGA_std:
+        printf("Loading Standard VGABIOS ...\n");
+        memcpy((void *)VGABIOS_PHYSICAL_ADDRESS,
+               vgabios_stdvga, sizeof(vgabios_stdvga));
+        vgabios_sz = round_option_rom(sizeof(vgabios_stdvga));
+        break;
+    case VGA_pt:
+        printf("Loading VGABIOS of passthroughed gfx ...\n");
+        vgabios_sz = round_option_rom(
+            (*(uint8_t *)(VGABIOS_PHYSICAL_ADDRESS+2)) * 512);
+        break;
+    default:
+        printf("No emulated VGA adaptor ...\n");
+        break;
+    }
+
+    etherboot_phys_addr = VGABIOS_PHYSICAL_ADDRESS + vgabios_sz;
+    if ( etherboot_phys_addr < OPTIONROM_PHYSICAL_ADDRESS )
+        etherboot_phys_addr = OPTIONROM_PHYSICAL_ADDRESS;
+    etherboot_sz = scan_etherboot_nic(OPTIONROM_PHYSICAL_END,
+                                      etherboot_phys_addr,
+                                      etherboot);
+
+    option_rom_phys_addr = etherboot_phys_addr + etherboot_sz;
+    option_rom_sz = pci_load_option_roms(OPTIONROM_PHYSICAL_END,
+                                         option_rom_phys_addr);
+
+    printf("Option ROMs:\n");
+    if ( vgabios_sz )
+        printf(" %05x-%05x: VGA BIOS\n",
+               VGABIOS_PHYSICAL_ADDRESS,
+               VGABIOS_PHYSICAL_ADDRESS + vgabios_sz - 1);
+    if ( etherboot_sz )
+        printf(" %05x-%05x: Etherboot ROM\n",
+               etherboot_phys_addr,
+               etherboot_phys_addr + etherboot_sz - 1);
+    if ( option_rom_sz )
+        printf(" %05x-%05x: PCI Option ROMs\n",
+               option_rom_phys_addr,
+               option_rom_phys_addr + option_rom_sz - 1);
+}
+
 static void rombios_load(const struct bios_config *config)
 {
     uint32_t bioshigh;
@@ -158,10 +216,7 @@ struct bios_config rombios_config =  {
 
     .bios_address = ROMBIOS_PHYSICAL_ADDRESS,
 
-    .load_roms = 1,
-
-    .optionrom_start = OPTIONROM_PHYSICAL_ADDRESS,
-    .optionrom_end = OPTIONROM_PHYSICAL_END,
+    .load_roms = rombios_load_roms,
 
     .bios_load = rombios_load,
 
diff --git a/tools/firmware/hvmloader/seabios.c b/tools/firmware/hvmloader/seabios.c
index 3045157633..15ddf358a4 100644
--- a/tools/firmware/hvmloader/seabios.c
+++ b/tools/firmware/hvmloader/seabios.c
@@ -143,10 +143,7 @@ struct bios_config seabios_config = {
 
     .bios_address = SEABIOS_PHYSICAL_ADDRESS,
 
-    .load_roms = 0,
-
-    .optionrom_start = 0,
-    .optionrom_end = 0,
+    .load_roms = NULL,
 
     .bios_load = NULL,