arc: add cpu files

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Francois Bedard <fbedard@synopsys.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Heiko Schocher <hs@denx.de>

10 files changed, 734 insertions, 0 deletions

diff --git a/arch/arc/config.mk b/arch/arc/config.mk
new file mode 100644
index 0000000..76f4f7c
--- /dev/null
+++ b/arch/arc/config.mk
@@ -0,0 +1,31 @@
+#
+# Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+ifndef CONFIG_SYS_BIG_ENDIAN
+CONFIG_SYS_LITTLE_ENDIAN = 1
+endif
+
+ifdef CONFIG_SYS_LITTLE_ENDIAN
+CROSS_COMPILE ?= arc-buildroot-linux-uclibc-
+endif
+
+ifdef CONFIG_SYS_BIG_ENDIAN
+CROSS_COMPILE ?= arceb-buildroot-linux-uclibc-
+PLATFORM_LDFLAGS += -EB
+endif
+
+PLATFORM_CPPFLAGS += -ffixed-r25 -D__ARC__ -DCONFIG_ARC -gdwarf-2
+
+LDSCRIPT := $(SRCTREE)/$(CPUDIR)/u-boot.lds
+
+# Needed for relocation
+LDFLAGS_FINAL += -pie
+
+# Load address for standalone apps
+CONFIG_STANDALONE_LOAD_ADDR ?= 0x82000000
+
+# Support generic board on ARC
+__HAVE_ARCH_GENERIC_BOARD := y
diff --git a/arch/arc/cpu/arc700/Makefile b/arch/arc/cpu/arc700/Makefile
new file mode 100644
index 0000000..cdc5002
--- /dev/null
+++ b/arch/arc/cpu/arc700/Makefile
@@ -0,0 +1,13 @@
+#
+# Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+extra-y	+= start.o
+
+obj-y	+= cache.o
+obj-y	+= cpu.o
+obj-y	+= interrupts.o
+obj-y	+= reset.o
+obj-y	+= timer.o
diff --git a/arch/arc/cpu/arc700/cache.c b/arch/arc/cpu/arc700/cache.c
new file mode 100644
index 0000000..39d522d
--- /dev/null
+++ b/arch/arc/cpu/arc700/cache.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <config.h>
+#include <asm/arcregs.h>
+
+/* Bit values in IC_CTRL */
+#define IC_CTRL_CACHE_DISABLE	(1 << 0)
+
+/* Bit values in DC_CTRL */
+#define DC_CTRL_CACHE_DISABLE	(1 << 0)
+#define DC_CTRL_INV_MODE_FLUSH	(1 << 6)
+#define DC_CTRL_FLUSH_STATUS	(1 << 8)
+
+int icache_status(void)
+{
+	return (read_aux_reg(ARC_AUX_IC_CTRL) & IC_CTRL_CACHE_DISABLE) !=
+	       IC_CTRL_CACHE_DISABLE;
+}
+
+void icache_enable(void)
+{
+	write_aux_reg(ARC_AUX_IC_CTRL, read_aux_reg(ARC_AUX_IC_CTRL) &
+		      ~IC_CTRL_CACHE_DISABLE);
+}
+
+void icache_disable(void)
+{
+	write_aux_reg(ARC_AUX_IC_CTRL, read_aux_reg(ARC_AUX_IC_CTRL) |
+		      IC_CTRL_CACHE_DISABLE);
+}
+
+void invalidate_icache_all(void)
+{
+#ifndef CONFIG_SYS_ICACHE_OFF
+	/* Any write to IC_IVIC register triggers invalidation of entire I$ */
+	write_aux_reg(ARC_AUX_IC_IVIC, 1);
+#endif /* CONFIG_SYS_ICACHE_OFF */
+}
+
+int dcache_status(void)
+{
+	return (read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_CACHE_DISABLE) !=
+		DC_CTRL_CACHE_DISABLE;
+}
+
+void dcache_enable(void)
+{
+	write_aux_reg(ARC_AUX_DC_CTRL, read_aux_reg(ARC_AUX_DC_CTRL) &
+		      ~(DC_CTRL_INV_MODE_FLUSH | DC_CTRL_CACHE_DISABLE));
+}
+
+void dcache_disable(void)
+{
+	write_aux_reg(ARC_AUX_DC_CTRL, read_aux_reg(ARC_AUX_DC_CTRL) |
+		      DC_CTRL_CACHE_DISABLE);
+}
+
+void flush_dcache_all(void)
+{
+	/* Do flush of entire cache */
+	write_aux_reg(ARC_AUX_DC_FLSH, 1);
+
+	/* Wait flush end */
+	while (read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_FLUSH_STATUS)
+		;
+}
+
+#ifndef CONFIG_SYS_DCACHE_OFF
+static void dcache_flush_line(unsigned addr)
+{
+#if (CONFIG_ARC_MMU_VER > 2)
+	write_aux_reg(ARC_AUX_DC_PTAG, addr);
+#endif
+	write_aux_reg(ARC_AUX_DC_FLDL, addr);
+
+	/* Wait flush end */
+	while (read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_FLUSH_STATUS)
+		;
+
+#ifndef CONFIG_SYS_ICACHE_OFF
+	/*
+	 * Invalidate I$ for addresses range just flushed from D$.
+	 * If we try to execute data flushed above it will be valid/correct
+	 */
+#if (CONFIG_ARC_MMU_VER > 2)
+	write_aux_reg(ARC_AUX_IC_PTAG, addr);
+#endif
+	write_aux_reg(ARC_AUX_IC_IVIL, addr);
+#endif /* CONFIG_SYS_ICACHE_OFF */
+}
+#endif /* CONFIG_SYS_DCACHE_OFF */
+
+void flush_dcache_range(unsigned long start, unsigned long end)
+{
+#ifndef CONFIG_SYS_DCACHE_OFF
+	unsigned int addr;
+
+	start = start & (~(CONFIG_SYS_CACHELINE_SIZE - 1));
+	end = end & (~(CONFIG_SYS_CACHELINE_SIZE - 1));
+
+	for (addr = start; addr <= end; addr += CONFIG_SYS_CACHELINE_SIZE)
+		dcache_flush_line(addr);
+#endif /* CONFIG_SYS_DCACHE_OFF */
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long end)
+{
+#ifndef CONFIG_SYS_DCACHE_OFF
+	unsigned int addr;
+
+	start = start & (~(CONFIG_SYS_CACHELINE_SIZE - 1));
+	end = end & (~(CONFIG_SYS_CACHELINE_SIZE - 1));
+
+	for (addr = start; addr <= end; addr += CONFIG_SYS_CACHELINE_SIZE) {
+#if (CONFIG_ARC_MMU_VER > 2)
+		write_aux_reg(ARC_AUX_DC_PTAG, addr);
+#endif
+		write_aux_reg(ARC_AUX_DC_IVDL, addr);
+	}
+#endif /* CONFIG_SYS_DCACHE_OFF */
+}
+
+void invalidate_dcache_all(void)
+{
+#ifndef CONFIG_SYS_DCACHE_OFF
+	/* Write 1 to DC_IVDC register triggers invalidation of entire D$ */
+	write_aux_reg(ARC_AUX_DC_IVDC, 1);
+#endif /* CONFIG_SYS_DCACHE_OFF */
+}
+
+void flush_cache(unsigned long start, unsigned long size)
+{
+	flush_dcache_range(start, start + size);
+}
diff --git a/arch/arc/cpu/arc700/config.mk b/arch/arc/cpu/arc700/config.mk
new file mode 100644
index 0000000..3206ff4
--- /dev/null
+++ b/arch/arc/cpu/arc700/config.mk
@@ -0,0 +1,7 @@
+#
+# Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+PLATFORM_CPPFLAGS += -mA7
diff --git a/arch/arc/cpu/arc700/cpu.c b/arch/arc/cpu/arc700/cpu.c
new file mode 100644
index 0000000..50634b8
--- /dev/null
+++ b/arch/arc/cpu/arc700/cpu.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/arcregs.h>
+#include <asm/cache.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int arch_cpu_init(void)
+{
+#ifdef CONFIG_SYS_ICACHE_OFF
+	icache_disable();
+#else
+	icache_enable();
+	invalidate_icache_all();
+#endif
+
+	flush_dcache_all();
+#ifdef CONFIG_SYS_DCACHE_OFF
+	dcache_disable();
+#else
+	dcache_enable();
+#endif
+	timer_init();
+
+/* In simulation (ISS) "CHIPID" and "ARCNUM" are all "ff" */
+	if ((read_aux_reg(ARC_AUX_IDENTITY) & 0xffffff00) == 0xffffff00)
+		gd->arch.running_on_hw = 0;
+	else
+		gd->arch.running_on_hw = 1;
+
+	gd->cpu_clk = CONFIG_SYS_CLK_FREQ;
+	gd->ram_size = CONFIG_SYS_SDRAM_SIZE;
+
+	return 0;
+}
+
+int arch_early_init_r(void)
+{
+	gd->bd->bi_memstart = CONFIG_SYS_SDRAM_BASE;
+	gd->bd->bi_memsize = CONFIG_SYS_SDRAM_SIZE;
+	return 0;
+}
diff --git a/arch/arc/cpu/arc700/interrupts.c b/arch/arc/cpu/arc700/interrupts.c
new file mode 100644
index 0000000..d93a6eb
--- /dev/null
+++ b/arch/arc/cpu/arc700/interrupts.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/arcregs.h>
+#include <asm/ptrace.h>
+
+/* Bit values in STATUS32 */
+#define E1_MASK		(1 << 1)	/* Level 1 interrupts enable */
+#define E2_MASK		(1 << 2)	/* Level 2 interrupts enable */
+
+int interrupt_init(void)
+{
+	return 0;
+}
+
+/*
+ * returns true if interrupts had been enabled before we disabled them
+ */
+int disable_interrupts(void)
+{
+	int status = read_aux_reg(ARC_AUX_STATUS32);
+	int state = (status | E1_MASK | E2_MASK) ? 1 : 0;
+
+	status &= ~(E1_MASK | E2_MASK);
+	/* STATUS32 register is updated indirectly with "FLAG" instruction */
+	__asm__("flag %0" : : "r" (status));
+	return state;
+}
+
+void enable_interrupts(void)
+{
+	unsigned int status = read_aux_reg(ARC_AUX_STATUS32);
+
+	status |= E1_MASK | E2_MASK;
+	/* STATUS32 register is updated indirectly with "FLAG" instruction */
+	__asm__("flag %0" : : "r" (status));
+}
+
+static void print_reg_file(long *reg_rev, int start_num)
+{
+	unsigned int i;
+
+	/* Print 3 registers per line */
+	for (i = start_num; i < start_num + 25; i++) {
+		printf("r%02u: 0x%08lx\t", i, (unsigned long)*reg_rev);
+		if (((i + 1) % 3) == 0)
+			printf("\n");
+
+		/* Because pt_regs has registers reversed */
+		reg_rev--;
+	}
+
+	/* Add new-line if none was inserted in the end of loop above */
+	if (((i + 1) % 3) != 0)
+		printf("\n");
+}
+
+void show_regs(struct pt_regs *regs)
+{
+	printf("RET:\t0x%08lx\nBLINK:\t0x%08lx\nSTAT32:\t0x%08lx\n",
+	       regs->ret, regs->blink, regs->status32);
+	printf("GP: 0x%08lx\t r25: 0x%08lx\t\n", regs->r26, regs->r25);
+	printf("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n", regs->bta,
+	       regs->sp, regs->fp);
+	printf("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", regs->lp_start,
+	       regs->lp_end, regs->lp_count);
+
+	print_reg_file(&(regs->r0), 0);
+}
+
+void bad_mode(struct pt_regs *regs)
+{
+	if (regs)
+		show_regs(regs);
+
+	panic("Resetting CPU ...\n");
+}
+
+void do_memory_error(unsigned long address, struct pt_regs *regs)
+{
+	printf("Memory error exception @ 0x%lx\n", address);
+	bad_mode(regs);
+}
+
+void do_instruction_error(unsigned long address, struct pt_regs *regs)
+{
+	printf("Instruction error exception @ 0x%lx\n", address);
+	bad_mode(regs);
+}
+
+void do_machine_check_fault(unsigned long address, struct pt_regs *regs)
+{
+	printf("Machine check exception @ 0x%lx\n", address);
+	bad_mode(regs);
+}
+
+void do_interrupt_handler(void)
+{
+	printf("Interrupt fired\n");
+	bad_mode(0);
+}
+
+void do_itlb_miss(struct pt_regs *regs)
+{
+	printf("I TLB miss exception\n");
+	bad_mode(regs);
+}
+
+void do_dtlb_miss(struct pt_regs *regs)
+{
+	printf("D TLB miss exception\n");
+	bad_mode(regs);
+}
+
+void do_tlb_prot_violation(unsigned long address, struct pt_regs *regs)
+{
+	printf("TLB protection violation or misaligned access @ 0x%lx\n",
+	       address);
+	bad_mode(regs);
+}
+
+void do_privilege_violation(struct pt_regs *regs)
+{
+	printf("Privilege violation exception\n");
+	bad_mode(regs);
+}
+
+void do_trap(struct pt_regs *regs)
+{
+	printf("Trap exception\n");
+	bad_mode(regs);
+}
+
+void do_extension(struct pt_regs *regs)
+{
+	printf("Extension instruction exception\n");
+	bad_mode(regs);
+}
diff --git a/arch/arc/cpu/arc700/reset.c b/arch/arc/cpu/arc700/reset.c
new file mode 100644
index 0000000..98ebf1d
--- /dev/null
+++ b/arch/arc/cpu/arc700/reset.c
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <command.h>
+#include <common.h>
+
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	printf("Put your restart handler here\n");
+
+#ifdef DEBUG
+	/* Stop debug session here */
+	__asm__("brk");
+#endif
+	return 0;
+}
diff --git a/arch/arc/cpu/arc700/start.S b/arch/arc/cpu/arc700/start.S
new file mode 100644
index 0000000..563513b
--- /dev/null
+++ b/arch/arc/cpu/arc700/start.S
@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <asm-offsets.h>
+#include <config.h>
+#include <asm/arcregs.h>
+
+/*
+ * Note on the LD/ST addressing modes with address register write-back
+ *
+ * LD.a same as LD.aw
+ *
+ * LD.a    reg1, [reg2, x]  => Pre Incr
+ *      Eff Addr for load = [reg2 + x]
+ *
+ * LD.ab   reg1, [reg2, x]  => Post Incr
+ *      Eff Addr for load = [reg2]
+ */
+
+.macro PUSH reg
+	st.a	\reg, [%sp, -4]
+.endm
+
+.macro PUSHAX aux
+	lr	%r9, [\aux]
+	PUSH	%r9
+.endm
+
+.macro  SAVE_R1_TO_R24
+	PUSH	%r1
+	PUSH	%r2
+	PUSH	%r3
+	PUSH	%r4
+	PUSH	%r5
+	PUSH	%r6
+	PUSH	%r7
+	PUSH	%r8
+	PUSH	%r9
+	PUSH	%r10
+	PUSH	%r11
+	PUSH	%r12
+	PUSH	%r13
+	PUSH	%r14
+	PUSH	%r15
+	PUSH	%r16
+	PUSH	%r17
+	PUSH	%r18
+	PUSH	%r19
+	PUSH	%r20
+	PUSH	%r21
+	PUSH	%r22
+	PUSH	%r23
+	PUSH	%r24
+.endm
+
+.macro SAVE_ALL_SYS
+
+	st	%r0, [%sp]
+	lr	%r0, [%ecr]
+	st	%r0, [%sp, 8]	/* ECR */
+	st	%sp, [%sp, 4]
+
+	SAVE_R1_TO_R24
+	PUSH	%r25
+	PUSH	%gp
+	PUSH	%fp
+	PUSH	%blink
+	PUSHAX	%eret
+	PUSHAX	%erstatus
+	PUSH	%lp_count
+	PUSHAX	%lp_end
+	PUSHAX	%lp_start
+	PUSHAX	%erbta
+.endm
+
+.align 4
+.globl _start
+_start:
+	/* Critical system events */
+	j	reset			/* 0 - 0x000 */
+	j	memory_error		/* 1 - 0x008 */
+	j	instruction_error	/* 2 - 0x010 */
+
+	/* Device interrupts */
+.rept	29
+	j	interrupt_handler	/* 3:31 - 0x018:0xF8 */
+.endr
+	/* Exceptions */
+	j	EV_MachineCheck		/* 0x100, Fatal Machine check  (0x20) */
+	j	EV_TLBMissI		/* 0x108, Intruction TLB miss  (0x21) */
+	j	EV_TLBMissD		/* 0x110, Data TLB miss        (0x22) */
+	j	EV_TLBProtV		/* 0x118, Protection Violation (0x23)
+							or Misaligned Access  */
+	j	EV_PrivilegeV		/* 0x120, Privilege Violation  (0x24) */
+	j	EV_Trap			/* 0x128, Trap exception       (0x25) */
+	j	EV_Extension		/* 0x130, Extn Intruction Excp (0x26) */
+
+memory_error:
+	SAVE_ALL_SYS
+	lr	%r0, [%efa]
+	mov	%r1, %sp
+	j	do_memory_error
+
+instruction_error:
+	SAVE_ALL_SYS
+	lr	%r0, [%efa]
+	mov	%r1, %sp
+	j	do_instruction_error
+
+interrupt_handler:
+	/* Todo - save and restore CPU context when interrupts will be in use */
+	bl	do_interrupt_handler
+	rtie
+
+EV_MachineCheck:
+	SAVE_ALL_SYS
+	lr	%r0, [%efa]
+	mov	%r1, %sp
+	j	do_machine_check_fault
+
+EV_TLBMissI:
+	SAVE_ALL_SYS
+	mov	%r0, %sp
+	j	do_itlb_miss
+
+EV_TLBMissD:
+	SAVE_ALL_SYS
+	mov	%r0, %sp
+	j	do_dtlb_miss
+
+EV_TLBProtV:
+	SAVE_ALL_SYS
+	lr	%r0, [%efa]
+	mov	%r1, %sp
+	j	do_tlb_prot_violation
+
+EV_PrivilegeV:
+	SAVE_ALL_SYS
+	mov	%r0, %sp
+	j	do_privilege_violation
+
+EV_Trap:
+	SAVE_ALL_SYS
+	mov	%r0, %sp
+	j	do_trap
+
+EV_Extension:
+	SAVE_ALL_SYS
+	mov	%r0, %sp
+	j	do_extension
+
+
+reset:
+	/* Setup interrupt vector base that matches "__text_start" */
+	sr	__text_start, [ARC_AUX_INTR_VEC_BASE]
+
+	/* Setup stack pointer */
+	mov	%sp, CONFIG_SYS_INIT_SP_ADDR
+	mov	%fp, %sp
+
+	/* Clear bss */
+	mov	%r0, __bss_start
+	mov	%r1, __bss_end
+
+clear_bss:
+	st.ab	0, [%r0, 4]
+	brlt	%r0, %r1, clear_bss
+
+	/* Zero the one and only argument of "board_init_f" */
+	mov_s	%r0, 0
+	j	board_init_f
+
+/*
+ * void relocate_code (addr_sp, gd, addr_moni)
+ *
+ * This "function" does not return, instead it continues in RAM
+ * after relocating the monitor code.
+ *
+ * r0 = start_addr_sp
+ * r1 = new__gd
+ * r2 = relocaddr
+ */
+.align 4
+.globl	relocate_code
+relocate_code:
+	/*
+	 * r0-r12 might be clobbered by C functions
+	 * so we use r13-r16 for storage here
+	 */
+	mov	%r13, %r0		/* save addr_sp */
+	mov	%r14, %r1		/* save addr of gd */
+	mov	%r15, %r2		/* save addr of destination */
+
+	mov	%r16, %r2		/* %r9 - relocation offset */
+	sub	%r16, %r16, __image_copy_start
+
+/* Set up the stack */
+stack_setup:
+	mov	%sp, %r13
+	mov	%fp, %sp
+
+/* Check if monitor is loaded right in place for relocation */
+	mov	%r0, __image_copy_start
+	cmp	%r0, %r15		/* skip relocation if code loaded */
+	bz	do_board_init_r		/* in target location already */
+
+/* Copy data (__image_copy_start - __image_copy_end) to new location */
+	mov	%r1, %r15
+	mov	%r2, __image_copy_end
+	sub	%r2, %r2, %r0		/* r3 <- amount of bytes to copy */
+	asr	%r2, %r2, 2		/* r3 <- amount of words to copy */
+	mov	%lp_count, %r2
+	lp	copy_end
+	ld.ab	%r2,[%r0,4]
+	st.ab	%r2,[%r1,4]
+copy_end:
+
+/* Fix relocations related issues */
+	bl	do_elf_reloc_fixups
+#ifndef CONFIG_SYS_ICACHE_OFF
+	bl	invalidate_icache_all
+#endif
+#ifndef CONFIG_SYS_DCACHE_OFF
+	bl	flush_dcache_all
+#endif
+
+/* Update position of intterupt vector table */
+	lr	%r0, [ARC_AUX_INTR_VEC_BASE]	/* Read current position */
+	add	%r0, %r0, %r16			/* Update address */
+	sr	%r0, [ARC_AUX_INTR_VEC_BASE]	/* Write new position */
+
+do_board_init_r:
+/* Prepare for exection of "board_init_r" in relocated monitor */
+	mov	%r2, board_init_r	/* old address of "board_init_r()" */
+	add	%r2, %r2, %r16		/* new address of "board_init_r()" */
+	mov	%r0, %r14		/* 1-st parameter: gd_t */
+	mov	%r1, %r15		/* 2-nd parameter: dest_addr */
+	j	[%r2]
diff --git a/arch/arc/cpu/arc700/timer.c b/arch/arc/cpu/arc700/timer.c
new file mode 100644
index 0000000..a0acbbc
--- /dev/null
+++ b/arch/arc/cpu/arc700/timer.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <asm/arcregs.h>
+
+#define NH_MODE	(1 << 1)	/* Disable timer if CPU is halted */
+
+int timer_init(void)
+{
+	write_aux_reg(ARC_AUX_TIMER0_CTRL, NH_MODE);
+	/* Set max value for counter/timer */
+	write_aux_reg(ARC_AUX_TIMER0_LIMIT, 0xffffffff);
+	/* Set initial count value and restart counter/timer */
+	write_aux_reg(ARC_AUX_TIMER0_CNT, 0);
+	return 0;
+}
+
+unsigned long timer_read_counter(void)
+{
+	return read_aux_reg(ARC_AUX_TIMER0_CNT);
+}
diff --git a/arch/arc/cpu/arc700/u-boot.lds b/arch/arc/cpu/arc700/u-boot.lds
new file mode 100644
index 0000000..2d01b21
--- /dev/null
+++ b/arch/arc/cpu/arc700/u-boot.lds
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+OUTPUT_FORMAT("elf32-littlearc", "elf32-littlearc", "elf32-littlearc")
+OUTPUT_ARCH(arc)
+ENTRY(_start)
+SECTIONS
+{
+	. = ALIGN(4);
+	.text :	{
+		*(.__text_start)
+		*(.__image_copy_start)
+		CPUDIR/start.o (.text*)
+		*(.text*)
+	}
+
+	. = ALIGN(4);
+	.text_end :
+	{
+		*(.__text_end)
+	}
+
+	. = ALIGN(4);
+	.rodata : {
+		*(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*)))
+	}
+
+	. = ALIGN(4);
+	.data : {
+		*(.data*)
+	}
+
+	. = ALIGN(4);
+	.u_boot_list : {
+		KEEP(*(SORT(.u_boot_list*)));
+	}
+
+	. = ALIGN(4);
+	.rel_dyn_start : {
+		*(.__rel_dyn_start)
+	}
+
+	.rela.dyn : {
+		*(.rela.dyn)
+	}
+
+	.rel_dyn_end : {
+		*(.__rel_dyn_end)
+	}
+
+	. = ALIGN(4);
+	.bss_start : {
+		*(.__bss_start);
+	}
+
+	.bss : {
+		*(.bss*)
+	}
+
+	.bss_end : {
+		*(.__bss_end);
+	}
+
+	. = ALIGN(4);
+	.image_copy_end : {
+		*(.__image_copy_end)
+		*(.__init_end)
+	}
+}