Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 58 insertions, 0 deletions

diff --git a/include/hw/riscv/boot_opensbi.h b/include/hw/riscv/boot_opensbi.h
new file mode 100644
index 000000000..0d5ddd6c3
--- /dev/null
+++ b/include/hw/riscv/boot_opensbi.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (c) 2019 Western Digital Corporation or its affiliates.
+ *
+ * Based on include/sbi/{fw_dynamic.h,sbi_scratch.h} from the OpenSBI project.
+ */
+#ifndef OPENSBI_H
+#define OPENSBI_H
+
+/** Expected value of info magic ('OSBI' ascii string in hex) */
+#define FW_DYNAMIC_INFO_MAGIC_VALUE     0x4942534f
+
+/** Maximum supported info version */
+#define FW_DYNAMIC_INFO_VERSION         0x2
+
+/** Possible next mode values */
+#define FW_DYNAMIC_INFO_NEXT_MODE_U     0x0
+#define FW_DYNAMIC_INFO_NEXT_MODE_S     0x1
+#define FW_DYNAMIC_INFO_NEXT_MODE_M     0x3
+
+enum sbi_scratch_options {
+    /** Disable prints during boot */
+    SBI_SCRATCH_NO_BOOT_PRINTS = (1 << 0),
+    /** Enable runtime debug prints */
+    SBI_SCRATCH_DEBUG_PRINTS = (1 << 1),
+};
+
+/** Representation dynamic info passed by previous booting stage */
+struct fw_dynamic_info {
+    /** Info magic */
+    target_long magic;
+    /** Info version */
+    target_long version;
+    /** Next booting stage address */
+    target_long next_addr;
+    /** Next booting stage mode */
+    target_long next_mode;
+    /** Options for OpenSBI library */
+    target_long options;
+    /**
+     * Preferred boot HART id
+     *
+     * It is possible that the previous booting stage uses same link
+     * address as the FW_DYNAMIC firmware. In this case, the relocation
+     * lottery mechanism can potentially overwrite the previous booting
+     * stage while other HARTs are still running in the previous booting
+     * stage leading to boot-time crash. To avoid this boot-time crash,
+     * the previous booting stage can specify last HART that will jump
+     * to the FW_DYNAMIC firmware as the preferred boot HART.
+     *
+     * To avoid specifying a preferred boot HART, the previous booting
+     * stage can set it to -1UL which will force the FW_DYNAMIC firmware
+     * to use the relocation lottery mechanism.
+     */
+    target_long boot_hart;
+};
+
+#endif