hw/arm/aspeed: Add support for loading vbootrom image via "-bios"

Introduce "aspeed_load_vbootrom()" to support loading a virtual boot ROM image
into the vbootrom memory region, using the "-bios" command-line option.

Introduce a new "vbootrom" field in the AspeedMachineClass to indicate whether
a machine supports the virtual boot ROM region.

Set this field to true by default for the AST2700-A0 and AST2700-A1 EVB
machines.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Nabih Estefan <nabihestefan@google.com>
Tested-by: Nabih Estefan <nabihestefan@google.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250424075135.3715128-4-jamin_lin@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/arm/aspeed.c

@@ -27,6 +27,7 @@
 #include "system/reset.h"
 #include "hw/loader.h"
 #include "qemu/error-report.h"
+#include "qemu/datadir.h"
 #include "qemu/units.h"
 #include "hw/qdev-clock.h"
 #include "system/system.h"
@@ -305,6 +306,33 @@ static void aspeed_install_boot_rom(AspeedMachineState *bmc, BlockBackend *blk,
                    rom_size, &error_abort);
 }
 
+#define VBOOTROM_FILE_NAME  "ast27x0_bootrom.bin"
+
+/*
+ * This function locates the vbootrom image file specified via the command line
+ * using the -bios option. It loads the specified image into the vbootrom
+ * memory region and handles errors if the file cannot be found or loaded.
+ */
+static void aspeed_load_vbootrom(AspeedMachineState *bmc, const char *bios_name,
+                                 Error **errp)
+{
+    g_autofree char *filename = NULL;
+    AspeedSoCState *soc = bmc->soc;
+    int ret;
+
+    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
+    if (!filename) {
+        error_setg(errp, "Could not find vbootrom image '%s'", bios_name);
+        return;
+    }
+
+    ret = load_image_mr(filename, &soc->vbootrom);
+    if (ret < 0) {
+        error_setg(errp, "Failed to load vbootrom image '%s'", bios_name);
+        return;
+    }
+}
+
 void aspeed_board_init_flashes(AspeedSMCState *s, const char *flashtype,
                                       unsigned int count, int unit0)
 {
@@ -380,6 +408,7 @@ static void aspeed_machine_init(MachineState *machine)
     AspeedMachineClass *amc = ASPEED_MACHINE_GET_CLASS(machine);
     AspeedSoCClass *sc;
     int i;
+    const char *bios_name = NULL;
     DriveInfo *emmc0 = NULL;
     bool boot_emmc;
 
@@ -482,6 +511,11 @@ static void aspeed_machine_init(MachineState *machine)
         }
     }
 
+    if (amc->vbootrom) {
+        bios_name = machine->firmware ?: VBOOTROM_FILE_NAME;
+        aspeed_load_vbootrom(bmc, bios_name, &error_abort);
+    }
+
     arm_load_kernel(ARM_CPU(first_cpu), machine, &aspeed_board_binfo);
 }
 
@@ -1701,6 +1735,7 @@ static void aspeed_machine_ast2700a0_evb_class_init(ObjectClass *oc,
     amc->macs_mask = ASPEED_MAC0_ON | ASPEED_MAC1_ON | ASPEED_MAC2_ON;
     amc->uart_default = ASPEED_DEV_UART12;
     amc->i2c_init  = ast2700_evb_i2c_init;
+    amc->vbootrom = true;
     mc->auto_create_sdcard = true;
     mc->default_ram_size = 1 * GiB;
     aspeed_machine_class_init_cpus_defaults(mc);
@@ -1722,6 +1757,7 @@ static void aspeed_machine_ast2700a1_evb_class_init(ObjectClass *oc,
     amc->macs_mask = ASPEED_MAC0_ON | ASPEED_MAC1_ON | ASPEED_MAC2_ON;
     amc->uart_default = ASPEED_DEV_UART12;
     amc->i2c_init  = ast2700_evb_i2c_init;
+    amc->vbootrom = true;
     mc->auto_create_sdcard = true;
     mc->default_ram_size = 1 * GiB;
     aspeed_machine_class_init_cpus_defaults(mc);

include/hw/arm/aspeed.h

@@ -40,6 +40,7 @@ struct AspeedMachineClass {
     void (*i2c_init)(AspeedMachineState *bmc);
     uint32_t uart_default;
     bool sdhci_wp_inverted;
+    bool vbootrom;
 };