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, 19 insertions, 0 deletions

diff --git a/target/riscv/cpu_user.h b/target/riscv/cpu_user.h
new file mode 100644
index 000000000..02afad608
--- /dev/null
+++ b/target/riscv/cpu_user.h
@@ -0,0 +1,19 @@
+#ifndef TARGET_RISCV_CPU_USER_H
+#define TARGET_RISCV_CPU_USER_H
+
+#define xRA 1   /* return address (aka link register) */
+#define xSP 2   /* stack pointer */
+#define xGP 3   /* global pointer */
+#define xTP 4   /* thread pointer */
+
+#define xA0 10  /* gpr[10-17] are syscall arguments */
+#define xA1 11
+#define xA2 12
+#define xA3 13
+#define xA4 14
+#define xA5 15
+#define xA6 16
+#define xA7 17  /* syscall number for RVI ABI */
+#define xT0 5   /* syscall number for RVE ABI */
+
+#endif