14 files changed, 993 insertions, 0 deletions

diff --git a/platform/common/fdt.c b/platform/common/fdt.c
new file mode 100644
index 0000000..4f6017c
--- /dev/null
+++ b/platform/common/fdt.c
@@ -0,0 +1,314 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <plat/fdt.h>
+
+#define FDT_MAGIC	0xd00dfeed
+#define FDT_VERSION	17
+
+struct fdt_header {
+	u32 magic;
+	u32 totalsize;
+	u32 off_dt_struct;
+	u32 off_dt_strings;
+	u32 off_mem_rsvmap;
+	u32 version;
+	u32 last_comp_version; /* <= 17 */
+	u32 boot_cpuid_phys;
+	u32 size_dt_strings;
+	u32 size_dt_struct;
+} __attribute__((packed));
+
+#define FDT_BEGIN_NODE	1
+#define FDT_END_NODE	2
+#define FDT_PROP	3
+#define FDT_NOP		4
+#define FDT_END		9
+
+u32 fdt_rev32(u32 v)
+{
+	return ((v & 0x000000FF) << 24) |
+	       ((v & 0x0000FF00) << 8) |
+	       ((v & 0x00FF0000) >> 8) |
+	       ((v & 0xFF000000) >> 24);
+}
+
+ulong fdt_strlen(const char *str)
+{
+	ulong ret = 0;
+
+	while (*str != '\0') {
+		ret++;
+		str++;
+	}
+
+	return ret;
+}
+
+int fdt_strcmp(const char *a, const char *b)
+{
+	/* search first diff or end of string */
+	for (; *a == *b && *a != '\0'; a++, b++);
+	return *a - *b;
+}
+
+int fdt_prop_string_index(const struct fdt_prop *prop,
+			  const char *str)
+{
+	int i;
+	ulong l = 0;
+	const char *p, *end;
+
+	p = prop->value;
+	end = p + prop->len;
+
+	for (i = 0; p < end; i++, p += l) {
+		l = fdt_strlen(p) + 1;
+		if (p + l > end)
+			return -1;
+		if (fdt_strcmp(str, p) == 0)
+			return i; /* Found it; return index */
+	}
+
+	return -1;
+}
+
+struct recursive_iter_info {
+	void (*fn)(const struct fdt_node *node,
+		   const struct fdt_prop *prop,
+		   void *priv);
+	void *fn_priv;
+	const char *str;
+};
+
+#define DATA32(ptr)	fdt_rev32(*((u32*)ptr))
+
+static void recursive_iter(char **data, struct recursive_iter_info *info,
+			   const struct fdt_node *parent)
+{
+	struct fdt_node node;
+	struct fdt_prop prop;
+
+	if (DATA32(*data) != FDT_BEGIN_NODE)
+		return;
+
+	node.data = *data;
+
+	(*data) += sizeof(u32);
+
+	node.parent = parent;
+	node.name = *data;
+
+	*data += fdt_strlen(*data) + 1;
+	while ((ulong)(*data) % sizeof(u32) != 0)
+		(*data)++;
+
+	node.depth = (parent) ? (parent->depth + 1) : 1;
+
+	/* Default cell counts, as per the FDT spec */
+	node.address_cells = 2;
+	node.size_cells = 1;
+
+	info->fn(&node, NULL, info->fn_priv);
+
+	while (DATA32(*data) != FDT_END_NODE) {
+		switch (DATA32(*data)) {
+		case FDT_PROP:
+			prop.node = &node;
+			*data += sizeof(u32);
+			prop.len = DATA32(*data);
+			*data += sizeof(u32);
+			prop.name = &info->str[DATA32(*data)];
+			*data += sizeof(u32);
+			prop.value = *data;
+			*data += prop.len;
+			while ((ulong)(*data) % sizeof(u32) != 0)
+				(*data)++;
+			info->fn(&node, &prop, info->fn_priv);
+			break;
+		case FDT_NOP:
+			*data += sizeof(u32);
+			break;
+		case FDT_BEGIN_NODE:
+			recursive_iter(data, info, &node);
+			break;
+		default:
+			return;
+		};
+	}
+
+	*data += sizeof(u32);
+}
+
+struct match_iter_info {
+	int (*match)(const struct fdt_node *node,
+		     const struct fdt_prop *prop,
+		     void *priv);
+	void *match_priv;
+	void (*fn)(const struct fdt_node *node,
+		   const struct fdt_prop *prop,
+		   void *priv);
+	void *fn_priv;
+	const char *str;
+};
+
+static void match_iter(const struct fdt_node *node,
+		       const struct fdt_prop *prop,
+		       void *priv)
+{
+	char *data;
+	struct match_iter_info *minfo = priv;
+	struct fdt_prop nprop;
+
+	/* Do nothing if node+prop dont match */
+	if (!minfo->match(node, prop, minfo->match_priv))
+		return;
+
+	/* Call function for node */
+	if (minfo->fn)
+		minfo->fn(node, NULL, minfo->fn_priv);
+
+	/* Convert node to character stream */
+	data = node->data;
+	data += sizeof(u32);
+
+	/* Skip node name */
+	data += fdt_strlen(data) + 1;
+	while ((ulong)(data) % sizeof(u32) != 0)
+		data++;
+
+	/* Find node property and its value */
+	while (DATA32(data) == FDT_PROP) {
+		nprop.node = node;
+		data += sizeof(u32);
+		nprop.len = DATA32(data);
+		data += sizeof(u32);
+		nprop.name = &minfo->str[DATA32(data)];
+		data += sizeof(u32);
+		nprop.value = data;
+		data += nprop.len;
+		while ((ulong)(data) % sizeof(u32) != 0)
+			(data)++;
+		/* Call function for every property */
+		if (minfo->fn)
+			minfo->fn(node, &nprop, minfo->fn_priv);
+	}
+}
+
+int fdt_match_node_prop(void *fdt,
+			int (*match)(const struct fdt_node *node,
+				     const struct fdt_prop *prop,
+				     void *priv),
+			void *match_priv,
+			void (*fn)(const struct fdt_node *node,
+				   const struct fdt_prop *prop,
+				   void *priv),
+			void *fn_priv)
+{
+	char *data;
+	u32 string_offset, data_offset;
+	struct fdt_header *header;
+	struct match_iter_info minfo;
+	struct recursive_iter_info rinfo;
+
+	if (!fdt || !match)
+		return -1;
+ 
+	header = fdt;
+	if (fdt_rev32(header->magic) != FDT_MAGIC ||
+	    fdt_rev32(header->last_comp_version) > FDT_VERSION)
+		return -1;
+	string_offset = fdt_rev32(header->off_dt_strings);
+	data_offset = fdt_rev32(header->off_dt_struct);
+
+	minfo.match = match;
+	minfo.match_priv = match_priv;
+	minfo.fn = fn;
+	minfo.fn_priv = fn_priv;
+	minfo.str = (const char *)(fdt + string_offset);
+
+	rinfo.fn = match_iter;
+	rinfo.fn_priv = &minfo;
+	rinfo.str = minfo.str;
+
+	data = (char *)(fdt + data_offset);
+	recursive_iter(&data, &rinfo, NULL);
+
+	return 0;
+}
+
+struct match_compat_info {
+	const char *compat;
+};
+
+static int match_compat(const struct fdt_node *node,
+			const struct fdt_prop *prop,
+			void *priv)
+{
+	struct match_compat_info *cinfo = priv;
+
+	if (!prop)
+		return 0;
+
+	if (fdt_strcmp(prop->name, "compatible"))
+		return 0;
+
+	if (fdt_prop_string_index(prop, cinfo->compat) < 0)
+		return 0;
+
+	return 1;
+}
+
+int fdt_compat_node_prop(void *fdt,
+			 const char *compat,
+			 void (*fn)(const struct fdt_node *node,
+				    const struct fdt_prop *prop,
+				    void *priv),
+			 void *fn_priv)
+{
+	struct match_compat_info cinfo = { .compat = compat };
+
+	return fdt_match_node_prop(fdt, match_compat, &cinfo,
+				       fn, fn_priv);
+}
+
+static int match_walk(const struct fdt_node *node,
+		      const struct fdt_prop *prop,
+		      void *priv)
+{
+	if (!prop)
+		return 1;
+
+	return 0;
+}
+
+int fdt_walk(void *fdt,
+	     void (*fn)(const struct fdt_node *node,
+			const struct fdt_prop *prop,
+			void *priv),
+	     void *fn_priv)
+{
+	return fdt_match_node_prop(fdt, match_walk, NULL,
+				       fn, fn_priv);
+}
+
+u32 fdt_size(void *fdt)
+{
+	struct fdt_header *header;
+
+	if (!fdt)
+		return 0;
+
+	header = fdt;
+	if (fdt_rev32(header->magic) != FDT_MAGIC ||
+	    fdt_rev32(header->last_comp_version) > FDT_VERSION)
+		return 0;
+
+	return fdt_rev32(header->totalsize);
+}
diff --git a/platform/common/include/plat/fdt.h b/platform/common/include/plat/fdt.h
new file mode 100644
index 0000000..246243f
--- /dev/null
+++ b/platform/common/include/plat/fdt.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#ifndef __FDT_H__
+#define __FDT_H__
+
+#include <sbi/sbi_types.h>
+
+struct fdt_node {
+	char *data;
+	const struct fdt_node *parent;
+	const char *name;
+	int depth;
+	int address_cells;
+	int size_cells;
+};
+
+struct fdt_prop {
+	const struct fdt_node *node;
+	const char *name;
+	void *value;
+	u32 len;
+};
+
+/* Reverse byte-order of 32bit number */
+u32 fdt_rev32(u32 v);
+
+/* Length of a string */
+ulong fdt_strlen(const char *str);
+
+/* Compate two strings */
+int fdt_strcmp(const char *a, const char *b);
+
+/* Find index of matching string from a list of strings */
+int fdt_prop_string_index(const struct fdt_prop *prop,
+			      const char *str);
+
+/* Iterate over each property of matching node */
+int fdt_match_node_prop(void *fdt,
+			int (*match)(const struct fdt_node *node,
+				     const struct fdt_prop *prop,
+				     void *priv),
+			void *match_priv,
+			void (*fn)(const struct fdt_node *node,
+				   const struct fdt_prop *prop,
+				   void *priv),
+			void *fn_priv);
+
+/* Iterate over each property of compatible node */
+int fdt_compat_node_prop(void *fdt,
+			 const char *compat,
+			 void (*fn)(const struct fdt_node *node,
+				    const struct fdt_prop *prop,
+				    void *priv),
+			 void *fn_priv);
+
+/* Iterate over each node and property */
+int fdt_walk(void *fdt,
+	     void (*fn)(const struct fdt_node *node,
+		 	const struct fdt_prop *prop,
+			void *priv),
+	     void *fn_priv);
+
+/* Get size of FDT */
+u32 fdt_size(void *fdt);
+
+#endif
diff --git a/platform/common/include/plat/irqchip/plic.h b/platform/common/include/plat/irqchip/plic.h
new file mode 100644
index 0000000..7c062aa
--- /dev/null
+++ b/platform/common/include/plat/irqchip/plic.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#ifndef __IRQCHIP_PLIC_H__
+#define __IRQCHIP_PLIC_H__
+
+#include <sbi/sbi_types.h>
+
+int plic_fdt_fixup(void *fdt, const char *compat);
+
+int plic_warm_irqchip_init(u32 target_hart);
+
+int plic_cold_irqchip_init(unsigned long base,
+			   u32 num_sources, u32 hart_count);
+
+#endif
diff --git a/platform/common/include/plat/serial/sifive-uart.h b/platform/common/include/plat/serial/sifive-uart.h
new file mode 100644
index 0000000..b932b16
--- /dev/null
+++ b/platform/common/include/plat/serial/sifive-uart.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#ifndef __SERIAL_SIFIVE_UART_H__
+#define __SERIAL_SIFIVE_UART_H__
+
+#include <sbi/sbi_types.h>
+
+void sifive_uart_putc(char ch);
+
+char sifive_uart_getc(void);
+
+int sifive_uart_init(unsigned long base,
+		     u32 in_freq, u32 baudrate);
+
+#endif
diff --git a/platform/common/include/plat/serial/uart8250.h b/platform/common/include/plat/serial/uart8250.h
new file mode 100644
index 0000000..ca19a9f
--- /dev/null
+++ b/platform/common/include/plat/serial/uart8250.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#ifndef __SERIAL_UART8250_H__
+#define __SERIAL_UART8250_H__
+
+#include <sbi/sbi_types.h>
+
+void uart8250_putc(char ch);
+
+char uart8250_getc(void);
+
+int uart8250_init(unsigned long base,
+		  u32 in_freq, u32 baudrate,
+		  u32 reg_shift, u32 reg_width);
+
+#endif
diff --git a/platform/common/include/plat/sys/clint.h b/platform/common/include/plat/sys/clint.h
new file mode 100644
index 0000000..642d83a
--- /dev/null
+++ b/platform/common/include/plat/sys/clint.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#ifndef __SYS_CLINT_H__
+#define __SYS_CLINT_H__
+
+#include <sbi/sbi_types.h>
+
+void clint_ipi_inject(u32 target_hart, u32 source_hart);
+
+void clint_ipi_sync(u32 target_hart, u32 source_hart);
+
+void clint_ipi_clear(u32 target_hart);
+
+int clint_warm_ipi_init(u32 target_hart);
+
+int clint_cold_ipi_init(unsigned long base, u32 hart_count);
+
+u64 clint_timer_value(void);
+
+void clint_timer_event_stop(u32 target_hart);
+
+void clint_timer_event_start(u32 target_hart, u64 next_event);
+
+int clint_warm_timer_init(u32 target_hart);
+
+int clint_cold_timer_init(unsigned long base, u32 hart_count);
+
+#endif
diff --git a/platform/common/irqchip/objects.mk b/platform/common/irqchip/objects.mk
new file mode 100644
index 0000000..84fffa6
--- /dev/null
+++ b/platform/common/irqchip/objects.mk
@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2018 Western Digital Corporation or its affiliates.
+#
+# Authors:
+#   Anup Patel <anup.patel@wdc.com>
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+platform-common-objs-$(PLATFORM_IRQCHIP_PLIC) += irqchip/plic.o
diff --git a/platform/common/irqchip/plic.c b/platform/common/irqchip/plic.c
new file mode 100644
index 0000000..404d1b7
--- /dev/null
+++ b/platform/common/irqchip/plic.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <sbi/riscv_io.h>
+#include <plat/fdt.h>
+#include <plat/irqchip/plic.h>
+
+#define PLIC_PRIORITY_BASE		0x0
+#define PLIC_PENDING_BASE		0x1000
+#define PLIC_ENABLE_BASE		0x2000
+#define PLIC_ENABLE_STRIDE		0x80
+#define PLIC_CONTEXT_BASE		0x200000
+#define PLIC_CONTEXT_STRIDE		0x1000
+
+static u32 plic_hart_count;
+static u32 plic_num_sources;
+static volatile void *plic_base;
+
+static void plic_set_priority(u32 source, u32 val)
+{
+	writel(val, plic_base);
+}
+
+static void plic_set_m_thresh(u32 hartid, u32 val)
+{
+	volatile void *plic_m_thresh = plic_base +
+				PLIC_CONTEXT_BASE +
+				PLIC_CONTEXT_STRIDE * (2 * hartid);
+	writel(val, plic_m_thresh);
+}
+
+static void plic_set_s_thresh(u32 hartid, u32 val)
+{
+	volatile void *plic_s_thresh = plic_base +
+				PLIC_CONTEXT_BASE +
+				PLIC_CONTEXT_STRIDE * (2 * hartid + 1);
+	writel(val, plic_s_thresh);
+}
+
+static void plic_set_s_ie(u32 hartid, u32 word_index, u32 val)
+{
+	volatile void *plic_s_ie = plic_base +
+				PLIC_ENABLE_BASE +
+				PLIC_ENABLE_STRIDE * (2 * hartid + 1);
+	writel(val, plic_s_ie + word_index * 4);
+}
+
+static void plic_fdt_fixup_prop(const struct fdt_node *node,
+				const struct fdt_prop *prop,
+				void *priv)
+{
+	u32 *cells;
+	u32 i, cells_count;
+
+	if (!prop)
+		return;
+	if (fdt_strcmp(prop->name, "interrupts-extended"))
+		return;
+
+	cells = prop->value;
+	cells_count = prop->len / sizeof(u32);
+
+	if (!cells_count)
+		return;
+
+	for (i = 0; i < cells_count; i++) {
+		if (i % 4 == 1)
+			cells[i] = fdt_rev32(0xffffffff);
+	}
+}
+
+int plic_fdt_fixup(void *fdt, const char *compat)
+{
+	fdt_compat_node_prop(fdt, compat, plic_fdt_fixup_prop, NULL);
+	return 0;
+}
+
+int plic_warm_irqchip_init(u32 target_hart)
+{
+	size_t i, ie_words = plic_num_sources / 32 + 1;
+
+	if (plic_hart_count <= target_hart)
+		return -1;
+
+	/* By default, enable all IRQs for S-mode of target HART */
+	for (i = 0; i < ie_words; i++)
+		plic_set_s_ie(target_hart, i, -1);
+
+	/* By default, enable M-mode threshold */
+	plic_set_m_thresh(target_hart, 1);
+
+	/* By default, disable S-mode threshold */
+	plic_set_s_thresh(target_hart, 0);
+
+	return 0;
+}
+
+int plic_cold_irqchip_init(unsigned long base,
+			   u32 num_sources, u32 hart_count)
+{
+	int i;
+
+	plic_hart_count = hart_count;
+	plic_num_sources = num_sources;
+	plic_base = (void *)base;
+
+	/* Configure default priorities of all IRQs */
+	for (i = 0; i < plic_num_sources; i++)
+		plic_set_priority(i, 1);
+
+	return 0;
+}
diff --git a/platform/common/objects.mk b/platform/common/objects.mk
new file mode 100644
index 0000000..712e950
--- /dev/null
+++ b/platform/common/objects.mk
@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2018 Western Digital Corporation or its affiliates.
+#
+# Authors:
+#   Anup Patel <anup.patel@wdc.com>
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+platform-common-objs-y += fdt.o
diff --git a/platform/common/serial/objects.mk b/platform/common/serial/objects.mk
new file mode 100644
index 0000000..cb6062d
--- /dev/null
+++ b/platform/common/serial/objects.mk
@@ -0,0 +1,11 @@
+#
+# Copyright (c) 2018 Western Digital Corporation or its affiliates.
+#
+# Authors:
+#   Anup Patel <anup.patel@wdc.com>
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+platform-common-objs-$(PLATFORM_SERIAL_UART8250) += serial/uart8250.o
+platform-common-objs-$(PLATFORM_SERIAL_SIFIVE_UART) += serial/sifive-uart.o
diff --git a/platform/common/serial/sifive-uart.c b/platform/common/serial/sifive-uart.c
new file mode 100644
index 0000000..60eade3
--- /dev/null
+++ b/platform/common/serial/sifive-uart.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <sbi/riscv_io.h>
+#include <sbi/sbi_console.h>
+#include <plat/serial/sifive-uart.h>
+
+#define UART_REG_TXFIFO		0
+#define UART_REG_RXFIFO		1
+#define UART_REG_TXCTRL		2
+#define UART_REG_RXCTRL		3
+#define UART_REG_IE		4
+#define UART_REG_IP		5
+#define UART_REG_DIV		6
+
+#define UART_TXFIFO_FULL	0x80000000
+#define UART_RXFIFO_EMPTY	0x80000000
+#define UART_RXFIFO_DATA	0x000000ff
+#define UART_TXCTRL_TXEN	0x1
+#define UART_RXCTRL_RXEN	0x1
+
+static volatile void *uart_base;
+static u32 uart_in_freq;
+static u32 uart_baudrate;
+
+/**
+ * Find minimum divisor divides in_freq to max_target_hz;
+ * Based on uart driver n SiFive FSBL.
+ *
+ * f_baud = f_in / (div + 1) => div = (f_in / f_baud) - 1
+ * The nearest integer solution requires rounding up as to not exceed max_target_hz.
+ * div  = ceil(f_in / f_baud) - 1
+ *	= floor((f_in - 1 + f_baud) / f_baud) - 1
+ * This should not overflow as long as (f_in - 1 + f_baud) does not exceed
+ * 2^32 - 1, which is unlikely since we represent frequencies in kHz.
+ */
+static inline unsigned int uart_min_clk_divisor(uint64_t in_freq,
+						uint64_t max_target_hz)
+{
+	uint64_t quotient = (in_freq + max_target_hz - 1) / (max_target_hz);
+	// Avoid underflow
+	if (quotient == 0) {
+		return 0;
+	} else {
+		return quotient - 1;
+	}
+}
+
+static u32 get_reg(u32 num)
+{
+	return readl(uart_base + (num * 0x4));
+}
+
+static void set_reg(u32 num, u32 val)
+{
+	writel(val, uart_base + (num * 0x4));
+}
+
+void sifive_uart_putc(char ch)
+{
+	while (get_reg(UART_REG_TXFIFO) & UART_TXFIFO_FULL);
+
+	set_reg(UART_REG_TXFIFO, ch);
+}
+
+char sifive_uart_getc(void)
+{
+	u32 ret = get_reg(UART_REG_RXFIFO);
+	if (!(ret & UART_RXFIFO_EMPTY))
+		return ret & UART_RXFIFO_DATA;
+	return 0;
+}
+
+int sifive_uart_init(unsigned long base,
+		     u32 in_freq, u32 baudrate)
+{
+	uart_base = (volatile void *)base;
+	uart_in_freq = in_freq;
+	uart_baudrate = baudrate;
+
+	/* Configure baudrate */
+	set_reg(UART_REG_DIV, uart_min_clk_divisor(in_freq, baudrate));
+	/* Disable interrupts */
+	set_reg(UART_REG_IE, 0);
+	/* Enable TX */
+	set_reg(UART_REG_TXCTRL, UART_TXCTRL_TXEN);
+	/* Enable Rx */
+	set_reg(UART_REG_RXCTRL, UART_RXCTRL_RXEN);
+
+	return 0;
+}
diff --git a/platform/common/serial/uart8250.c b/platform/common/serial/uart8250.c
new file mode 100644
index 0000000..7a99045
--- /dev/null
+++ b/platform/common/serial/uart8250.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <sbi/riscv_io.h>
+#include <plat/serial/uart8250.h>
+
+#define UART_RBR_OFFSET		0	/* In:  Recieve Buffer Register */
+#define UART_THR_OFFSET		0	/* Out: Transmitter Holding Register */
+#define UART_DLL_OFFSET		0	/* Out: Divisor Latch Low */
+#define UART_IER_OFFSET		1	/* I/O: Interrupt Enable Register */
+#define UART_DLM_OFFSET		1	/* Out: Divisor Latch High */
+#define UART_FCR_OFFSET		2	/* Out: FIFO Control Register */
+#define UART_IIR_OFFSET		2	/* I/O: Interrupt Identification Register */
+#define UART_LCR_OFFSET		3	/* Out: Line Control Register */
+#define UART_MCR_OFFSET		4	/* Out: Modem Control Register */
+#define UART_LSR_OFFSET		5	/* In:  Line Status Register */
+#define UART_MSR_OFFSET		6	/* In:  Modem Status Register */
+#define UART_SCR_OFFSET		7	/* I/O: Scratch Register */
+#define UART_MDR1_OFFSET	8	/* I/O:  Mode Register */
+
+#define UART_LSR_FIFOE		0x80    /* Fifo error */
+#define UART_LSR_TEMT		0x40    /* Transmitter empty */
+#define UART_LSR_THRE		0x20    /* Transmit-hold-register empty */
+#define UART_LSR_BI		0x10    /* Break interrupt indicator */
+#define UART_LSR_FE		0x08    /* Frame error indicator */
+#define UART_LSR_PE		0x04    /* Parity error indicator */
+#define UART_LSR_OE		0x02    /* Overrun error indicator */
+#define UART_LSR_DR		0x01    /* Receiver data ready */
+#define UART_LSR_BRK_ERROR_BITS	0x1E    /* BI, FE, PE, OE bits */
+
+static volatile void *uart8250_base;
+static u32 uart8250_in_freq;
+static u32 uart8250_baudrate;
+static u32 uart8250_reg_width;
+static u32 uart8250_reg_shift;
+
+static u32 get_reg(u32 num)
+{
+	u32 offset = num << uart8250_reg_shift;
+
+	if (uart8250_reg_width == 1)
+		return readb(uart8250_base + offset);
+	else if (uart8250_reg_width == 2)
+		return readw(uart8250_base + offset);
+	else
+		return readl(uart8250_base + offset);
+}
+
+static void set_reg(u32 num, u32 val)
+{
+	u32 offset = num << uart8250_reg_shift;
+
+	if (uart8250_reg_width == 1)
+		writeb(val, uart8250_base + offset);
+	else if (uart8250_reg_width == 2)
+		writew(val, uart8250_base + offset);
+	else
+		writel(val, uart8250_base + offset);
+}
+
+void uart8250_putc(char ch)
+{
+	while ((get_reg(UART_LSR_OFFSET) & UART_LSR_THRE) == 0);
+
+	set_reg(UART_THR_OFFSET, ch);
+}
+
+char uart8250_getc(void)
+{
+	if (get_reg(UART_LSR_OFFSET) & UART_LSR_DR)
+		return get_reg(UART_RBR_OFFSET);
+	return 0;
+}
+
+int uart8250_init(unsigned long base,
+		  u32 in_freq, u32 baudrate,
+		  u32 reg_shift, u32 reg_width)
+{
+	u16 bdiv;
+
+	uart8250_base = (volatile void *)base;
+	uart8250_reg_shift = reg_shift;
+	uart8250_reg_width = reg_width;
+	uart8250_in_freq = in_freq;
+	uart8250_baudrate = baudrate;
+
+	bdiv = uart8250_in_freq / (16 * uart8250_baudrate);
+
+	/* Disable all interrupts */
+	set_reg(UART_IER_OFFSET, 0x00);
+	/* Enable DLAB */
+	set_reg(UART_LCR_OFFSET, 0x80);
+	/* Set divisor low byte */
+	set_reg(UART_DLL_OFFSET, bdiv & 0xff);
+	/* Set divisor high byte */
+	set_reg(UART_DLM_OFFSET, (bdiv >> 8) & 0xff);
+	/* 8 bits, no parity, one stop bit */
+	set_reg(UART_LCR_OFFSET, 0x03);
+	/* Enable FIFO */
+	set_reg(UART_FCR_OFFSET, 0x01);
+	/* No modem control DTR RTS */
+	set_reg(UART_MCR_OFFSET, 0x00);
+	/* Clear line status */
+	get_reg(UART_LSR_OFFSET);
+	/* Read receive buffer */
+	get_reg(UART_RBR_OFFSET);
+	/* Set scratchpad */
+	set_reg(UART_SCR_OFFSET, 0x00);
+
+	return 0;
+}
diff --git a/platform/common/sys/clint.c b/platform/common/sys/clint.c
new file mode 100644
index 0000000..e84c382
--- /dev/null
+++ b/platform/common/sys/clint.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2018 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <sbi/riscv_io.h>
+#include <sbi/riscv_atomic.h>
+#include <plat/sys/clint.h>
+
+static u32 clint_ipi_hart_count;
+static volatile void *clint_ipi_base;
+static volatile u32 *clint_ipi;
+
+void clint_ipi_inject(u32 target_hart, u32 source_hart)
+{
+	if ((clint_ipi_hart_count <= target_hart) ||
+	    (clint_ipi_hart_count <= source_hart))
+		return;
+
+	/* Set CLINT IPI */
+	writel(1, &clint_ipi[target_hart]);
+}
+
+void clint_ipi_sync(u32 target_hart, u32 source_hart)
+{
+	u32 target_ipi, incoming_ipi;
+
+	if ((clint_ipi_hart_count <= target_hart) ||
+	    (clint_ipi_hart_count <= source_hart))
+		return;
+
+	/* Wait until target HART has handled IPI */
+	incoming_ipi = 0;
+	while (1) {
+		target_ipi = readl(&clint_ipi[target_hart]);
+		if (!target_ipi)
+			break;
+
+		incoming_ipi |=
+			atomic_raw_xchg_uint(&clint_ipi[source_hart], 0);
+	}
+
+	if (incoming_ipi)
+		writel(incoming_ipi, &clint_ipi[source_hart]);
+}
+
+void clint_ipi_clear(u32 target_hart)
+{
+	if (clint_ipi_hart_count <= target_hart)
+		return;
+
+	/* Clear CLINT IPI */
+	writel(0, &clint_ipi[target_hart]);
+}
+
+int clint_warm_ipi_init(u32 target_hart)
+{
+	if (clint_ipi_hart_count <= target_hart ||
+	    !clint_ipi_base)
+		return -1;
+
+	/* Clear CLINT IPI */
+	clint_ipi_clear(target_hart);
+
+	return 0;
+}
+
+int clint_cold_ipi_init(unsigned long base, u32 hart_count)
+{
+	/* Figure-out CLINT IPI register address */
+	clint_ipi_hart_count = hart_count;
+	clint_ipi_base = (void *)base;
+	clint_ipi = (u32 *)clint_ipi_base;
+
+	return 0;
+}
+
+static u32 clint_time_hart_count;
+static volatile void *clint_time_base;
+static volatile u64 *clint_time_val;
+static volatile u64 *clint_time_cmp;
+
+u64 clint_timer_value(void)
+{
+	return readq_relaxed(clint_time_val);
+}
+
+void clint_timer_event_stop(u32 target_hart)
+{
+	if (clint_time_hart_count <= target_hart)
+		return;
+
+	/* Clear CLINT Time Compare */
+	writeq_relaxed(-1ULL, &clint_time_cmp[target_hart]);
+}
+
+void clint_timer_event_start(u32 target_hart, u64 next_event)
+{
+	if (clint_time_hart_count <= target_hart)
+		return;
+
+	/* Program CLINT Time Compare */
+	writeq_relaxed(next_event, &clint_time_cmp[target_hart]);
+}
+
+int clint_warm_timer_init(u32 target_hart)
+{
+	if (clint_time_hart_count <= target_hart ||
+	    !clint_time_base)
+		return -1;
+
+	/* Clear CLINT Time Compare */
+	writeq_relaxed(-1ULL, &clint_time_cmp[target_hart]);
+
+	return 0;
+}
+
+int clint_cold_timer_init(unsigned long base, u32 hart_count)
+{
+	/* Figure-out CLINT Time register address */
+	clint_time_hart_count = hart_count;
+	clint_time_base = (void *)base;
+	clint_time_val = (u64 *)(clint_time_base + 0xbff8);
+	clint_time_cmp = (u64 *)(clint_time_base + 0x4000);
+
+	return 0;
+}
diff --git a/platform/common/sys/objects.mk b/platform/common/sys/objects.mk
new file mode 100644
index 0000000..183d8db
--- /dev/null
+++ b/platform/common/sys/objects.mk
@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2018 Western Digital Corporation or its affiliates.
+#
+# Authors:
+#   Anup Patel <anup.patel@wdc.com>
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+platform-common-objs-$(PLATFORM_SYS_CLINT) += sys/clint.o