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/arch/riscv/cpu/qemu/cpu.c b/arch/riscv/cpu/qemu/cpu.c
new file mode 100644
index 0000000..a064639
--- /dev/null
+++ b/arch/riscv/cpu/qemu/cpu.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <command.h>
+
+/*
+ * cleanup_before_linux() is called just before we call linux
+ * it prepares the processor for linux
+ *
+ * we disable interrupt and caches.
+ */
+int cleanup_before_linux(void)
+{
+ disable_interrupts();
+
+ /* turn off I/D-cache */
+
+ return 0;
+}
+
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+ printf("reset unsupported yet\n");
+
+ return 0;
+}