RISC-V Linux User Emulation

Implementation of linux user emulation for RISC-V.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Sagar Karandikar <sagark@eecs.berkeley.edu>
Signed-off-by: Michael Clark <mjc@sifive.com>

linux-user/riscv/target_signal.h

@@ -0,0 +1,23 @@
+#ifndef TARGET_SIGNAL_H
+#define TARGET_SIGNAL_H
+
+#include "cpu.h"
+
+typedef struct target_sigaltstack {
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
+} target_stack_t;
+
+#define TARGET_SS_ONSTACK 1
+#define TARGET_SS_DISABLE 2
+
+#define TARGET_MINSIGSTKSZ 2048
+#define TARGET_SIGSTKSZ 8192
+
+static inline abi_ulong get_sp_from_cpustate(CPURISCVState *state)
+{
+   return state->gpr[xSP];
+}
+
+#endif /* TARGET_SIGNAL_H */