hw/riscv: virt: Enable booting S-mode firmware from pflash

To boot S-mode firmware payload like EDK2 from persistent
flash storage, qemu needs to pass the flash address as the
next_addr in fw_dynamic_info to the opensbi.

When both -kernel and -pflash options are provided in command line,
the kernel (and initrd if -initrd) will be copied to fw_cfg table.
The S-mode FW will load the kernel/initrd from fw_cfg table.

If only pflash is given but not -kernel, then it is the job of
of the S-mode firmware to locate and load the kernel.

In either case, update the kernel_entry with the flash address
so that the opensbi can jump to the entry point of the S-mode
firmware.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221004092351.18209-4-sunilvl@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index de2efccebf..a5bc7353b4 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -1274,7 +1274,23 @@ static void virt_machine_done(Notifier *notifier, void *data)
     s->fw_cfg = create_fw_cfg(machine);
     rom_set_fw(s->fw_cfg);
 
-    if (machine->kernel_filename) {
+    if (drive_get(IF_PFLASH, 0, 1)) {
+        /*
+         * S-mode FW like EDK2 will be kept in second plash (unit 1).
+         * When both kernel, initrd and pflash options are provided in the
+         * command line, the kernel and initrd will be copied to the fw_cfg
+         * table and opensbi will jump to the flash address which is the
+         * entry point of S-mode FW. It is the job of the S-mode FW to load
+         * the kernel and initrd using fw_cfg table.
+         *
+         * If only pflash is given but not -kernel, then it is the job of
+         * of the S-mode firmware to locate and load the kernel.
+         * In either case, the next_addr for opensbi will be the flash address.
+         */
+        riscv_setup_firmware_boot(machine);
+        kernel_entry = virt_memmap[VIRT_FLASH].base +
+                       virt_memmap[VIRT_FLASH].size / 2;
+    } else if (machine->kernel_filename) {
         kernel_start_addr = riscv_calc_kernel_start_addr(&s->soc[0],
                                                          firmware_end_addr);