riscv: Add QEMU virt board support
This adds QEMU RISC-V 'virt' board target support, with the hope of
helping people easily test U-Boot on RISC-V.
The QEMU virt machine models a generic RISC-V virtual machine with
support for the VirtIO standard networking and block storage devices.
It has CLINT, PLIC, 16550A UART devices in addition to VirtIO and
it also uses device-tree to pass configuration information to guest
software. It implements RISC-V privileged architecture spec v1.10.
Both 32-bit and 64-bit builds are supported. Support is pretty much
preliminary, only booting to U-Boot shell with the UART driver on
a single core. Booting Linux is not supported yet.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
diff --git a/board/emulation/qemu-riscv/qemu-riscv.c b/board/emulation/qemu-riscv/qemu-riscv.c
new file mode 100644
index 0000000..041e716
--- /dev/null
+++ b/board/emulation/qemu-riscv/qemu-riscv.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+
+#define MROM_FDT_ADDR 0x1020
+
+int board_init(void)
+{
+ return 0;
+}
+
+void *board_fdt_blob_setup(void)
+{
+ /*
+ * QEMU loads a generated DTB for us immediately
+ * after the reset vectors in the MROM
+ */
+ return (void *)MROM_FDT_ADDR;
+}