[opensbi] create opensbi from T-Head official:

repo: https://github.com/T-head-Semi/opensbi
	commit: 89182b257c8798e15e4c685c1af0c2862d528d2a

Change-Id: I7b39d66729e0108661a6f4c9e28acbdb303684ea

opensbi/lib/sbi/sbi_platform.c

@@ -0,0 +1,81 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Atish Patra <atish.patra@wdc.com>
+ */
+
+#include <sbi/sbi_console.h>
+#include <sbi/sbi_platform.h>
+#include <sbi/sbi_string.h>
+
+static inline char *sbi_platform_feature_id2string(unsigned long feature)
+{
+	char *fstr = NULL;
+
+	if (!feature)
+		return NULL;
+
+	switch (feature) {
+	case SBI_PLATFORM_HAS_MFAULTS_DELEGATION:
+		fstr = "mfdeleg";
+		break;
+	default:
+		break;
+	}
+
+	return fstr;
+}
+
+void sbi_platform_get_features_str(const struct sbi_platform *plat,
+				   char *features_str, int nfstr)
+{
+	unsigned long features, feat = 1UL;
+	char *temp;
+	int offset = 0;
+
+	if (!plat || !features_str || !nfstr)
+		return;
+	sbi_memset(features_str, 0, nfstr);
+
+	features = sbi_platform_get_features(plat);
+	if (!features)
+		goto done;
+
+	do {
+		if (features & feat) {
+			temp = sbi_platform_feature_id2string(feat);
+			if (temp) {
+				sbi_snprintf(features_str + offset, nfstr,
+					     "%s,", temp);
+				offset = offset + sbi_strlen(temp) + 1;
+			}
+		}
+		feat = feat << 1;
+	} while (feat <= SBI_PLATFORM_HAS_LAST_FEATURE);
+
+done:
+	if (offset)
+		features_str[offset - 1] = '\0';
+	else
+		sbi_strncpy(features_str, "none", nfstr);
+}
+
+u32 sbi_platform_hart_index(const struct sbi_platform *plat, u32 hartid)
+{
+	u32 i;
+
+	if (!plat)
+		return -1U;
+	if (plat->hart_index2id) {
+		for (i = 0; i < plat->hart_count; i++) {
+			if (plat->hart_index2id[i] == hartid)
+				return i;
+		}
+		return -1U;
+	}
+
+	return hartid;
+}