[opensbi] create opensbi from T-Head official:

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

Change-Id: I7b39d66729e0108661a6f4c9e28acbdb303684ea

opensbi/lib/sbi/sbi_system.c

@@ -0,0 +1,74 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2019 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *   Nick Kossifidis <mick@ics.forth.gr>
+ */
+
+#include <sbi/riscv_asm.h>
+#include <sbi/sbi_bitops.h>
+#include <sbi/sbi_domain.h>
+#include <sbi/sbi_hart.h>
+#include <sbi/sbi_hsm.h>
+#include <sbi/sbi_platform.h>
+#include <sbi/sbi_system.h>
+#include <sbi/sbi_ipi.h>
+#include <sbi/sbi_init.h>
+
+static const struct sbi_system_reset_device *reset_dev = NULL;
+
+const struct sbi_system_reset_device *sbi_system_reset_get_device(void)
+{
+	return reset_dev;
+}
+
+void sbi_system_reset_set_device(const struct sbi_system_reset_device *dev)
+{
+	if (!dev || reset_dev)
+		return;
+
+	reset_dev = dev;
+}
+
+bool sbi_system_reset_supported(u32 reset_type, u32 reset_reason)
+{
+	if (reset_dev && reset_dev->system_reset_check &&
+	    reset_dev->system_reset_check(reset_type, reset_reason))
+		return TRUE;
+
+	return FALSE;
+}
+
+#include <sbi/riscv_io.h>
+void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason)
+{
+	ulong hbase = 0, hmask;
+	u32 cur_hartid = current_hartid();
+	struct sbi_domain *dom = sbi_domain_thishart_ptr();
+	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
+
+	/* Send HALT IPI to every hart other than the current hart */
+	while (!sbi_hsm_hart_interruptible_mask(dom, hbase, &hmask)) {
+		if (hbase <= cur_hartid)
+			hmask &= ~(1UL << (cur_hartid - hbase));
+		if (hmask)
+			sbi_ipi_send_halt(hmask, hbase);
+		hbase += BITS_PER_LONG;
+	}
+
+	/* Stop current HART */
+	sbi_hsm_hart_stop(scratch, FALSE);
+
+	/* Platform specific reset if domain allowed system reset */
+	if (dom->system_reset_allowed &&
+	    reset_dev && reset_dev->system_reset)
+		reset_dev->system_reset(reset_type, reset_reason);
+
+	writew(0x5555, (void *)0x100000); // qemu poweroff
+
+	/* If platform specific reset did not work then do sbi_exit() */
+	sbi_exit(scratch);
+}