minute-ia: Enable x86 core for Intel ISH

Add intial minute-IA (x86) core to to enable the FW to boot on Intel Integrated Sensor Hub (ISH). BUG=chrome-os-partner:51851 BRANCH=None TEST=`make buildall -j` Change-Id: I4dcf841766f216cd00fb1d4214fae19ba5de5603 Signed-off-by: Jaiber John <jaiber.j.john@intel.com> Signed-off-by: Alex Brill <alexander.brill@intel.com> Reviewed-on: https://chromium-review.googlesource.com/336443 Commit-Ready: Raj Mojumder <raj.mojumder@intel.com> Tested-by: Raj Mojumder <raj.mojumder@intel.com> Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2026-01-09 00:51:29 +00:00 · 2016-03-31 23:34:34 +05:30
parent d54387c18e
commit a625b710c3
17 changed files with 1919 additions and 0 deletions
--- a/core/minute-ia/atomic.c
+++ b/core/minute-ia/atomic.c
@@ -0,0 +1,71 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "atomic.h"
+
+inline int bool_compare_and_swap_u32(uint32_t *var, uint32_t old_value,
+		uint32_t new_value)
+{
+	uint32_t _old_value = old_value;
+
+	__asm__ __volatile__("cmpxchg %1, %2\n"
+			: "=a"(old_value)
+			: "r"(new_value), "m"(*var), "a" (old_value)
+			: "memory");
+
+	return (_old_value == old_value);
+}
+
+inline void atomic_or_u8(uint8_t *addr, uint8_t bits)
+{
+	ATOMIC_OP(or, addr, bits);
+}
+
+inline void atomic_and_u8(uint8_t *addr, uint8_t bits)
+{
+	ATOMIC_OP(and, addr, bits);
+}
+
+inline void atomic_clear(uint32_t volatile *addr, uint32_t bits)
+{
+	ATOMIC_OP(btr, addr, bits >> 1);
+}
+
+inline void atomic_or(uint32_t volatile *addr, uint32_t bits)
+{
+	ATOMIC_OP(orl, addr, bits);
+}
+
+inline void atomic_add(uint32_t volatile *addr, uint32_t value)
+{
+	ATOMIC_OP(addl, addr, value);
+}
+
+inline void atomic_and(uint32_t volatile *addr, uint32_t value)
+{
+	ATOMIC_OP(andl, addr, value);
+}
+
+inline void atomic_sub(uint32_t volatile *addr, uint32_t value)
+{
+	ATOMIC_OP(subl, addr, value);
+}
+
+inline uint32_t atomic_read_clear(uint32_t volatile *addr)
+{
+	int loc = 0;
+
+	if (*addr == 0)
+		return 0;
+
+	asm volatile("bsr %1, %0\n"
+		     "lock; btr %0, %1\n"
+			: "=&r" (loc)
+			: "m" (*addr)
+			: "memory"
+		    );
+
+	return (1 << loc);
+}
--- a/core/minute-ia/atomic.h
+++ b/core/minute-ia/atomic.h
@@ -0,0 +1,33 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Atomic operations for x86 */
+
+#ifndef __CROS_EC_ATOMIC_H
+#define __CROS_EC_ATOMIC_H
+
+#include "common.h"
+#include "util.h"
+
+#define ATOMIC_OP(asm_op, a, v) do {		\
+	__asm__ __volatile__ (			\
+		"lock;" #asm_op " %0, %1\n"	\
+		: 				\
+		: "r" (v), "m" (*a)		\
+		: "memory");			\
+} while (0)
+
+inline int bool_compare_and_swap_u32(uint32_t *var, uint32_t old_value,
+		uint32_t new_value);
+inline void atomic_or_u8(uint8_t *var, uint8_t value);
+inline void atomic_and_u8(uint8_t *var, uint8_t value);
+inline void atomic_clear(uint32_t volatile *addr, uint32_t bits);
+inline void atomic_or(uint32_t volatile *addr, uint32_t bits);
+inline void atomic_add(uint32_t volatile *addr, uint32_t value);
+inline void atomic_and(uint32_t volatile *addr, uint32_t value);
+inline void atomic_sub(uint32_t volatile *addr, uint32_t value);
+inline uint32_t atomic_read_clear(uint32_t volatile *addr);
+
+#endif  /* __CROS_EC_ATOMIC_H */
--- a/core/minute-ia/build.mk
+++ b/core/minute-ia/build.mk
@@ -0,0 +1,32 @@
+# -*- makefile -*-
+# Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# Minute-IA core build
+#
+
+# Select Minute-IA bare-metal toolchain
+CROSS_COMPILE?=i686-pc-linux-gnu-
+
+# FPU compilation flags
+CFLAGS_FPU-$(CONFIG_FPU)=
+
+# CPU specific compilation flags
+CFLAGS_CPU+=-fno-omit-frame-pointer -mno-accumulate-outgoing-args	\
+	    -ffunction-sections -fdata-sections				\
+	    -fno-builtin-printf -fno-builtin-sprintf	 		\
+	    -fno-stack-protector -gdwarf-2  -fno-common -ffreestanding	\
+	    -minline-all-stringops -fno-strict-aliasing
+
+CFLAGS_CPU+=$(CFLAGS_FPU-y)
+
+ifneq ($(CONFIG_LTO),)
+CFLAGS_CPU+=-flto
+LDFLAGS_EXTRA+=-flto
+endif
+
+core-y=cpu.o init.o interrupts.o atomic.o
+core-$(CONFIG_COMMON_PANIC_OUTPUT)+=panic.o
+core-$(CONFIG_COMMON_RUNTIME)+=switch.o task.o
+core-$(CONFIG_MPU)+=mpu.o
--- a/core/minute-ia/config_core.h
+++ b/core/minute-ia/config_core.h
@@ -0,0 +1,15 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_CONFIG_CORE_H
+#define __CROS_EC_CONFIG_CORE_H
+
+/* Linker binary architecture and format */
+#define BFD_ARCH "i386"
+#define BFD_FORMAT "elf32-i386"
+
+#define CONFIG_SOFTWARE_PANIC
+
+#endif /* __CROS_EC_CONFIG_CORE_H */
--- a/core/minute-ia/cpu.c
+++ b/core/minute-ia/cpu.c
@@ -0,0 +1,15 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Set up the LM2 mIA core
+ */
+
+#include <cpu.h>
+
+
+void cpu_init(void)
+{
+	/* Nothing to do now */
+	return;
+}
--- a/core/minute-ia/cpu.h
+++ b/core/minute-ia/cpu.h
@@ -0,0 +1,13 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Registers map and defintions for mIA LM2 processor
+ */
+
+#ifndef __CROS_EC_CPU_H
+#define __CROS_EC_CPU_H
+
+
+void cpu_init(void);
+#endif	/* __CROS_EC_CPU_H */
--- a/core/minute-ia/ec.lds.S
+++ b/core/minute-ia/ec.lds.S
@@ -0,0 +1,160 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "config.h"
+#include "rsa.h"
+
+OUTPUT_FORMAT(BFD_FORMAT, BFD_FORMAT, BFD_FORMAT)
+OUTPUT_ARCH(BFD_ARCH)
+ENTRY(reset)
+
+SECTIONS
+{
+	. = CONFIG_ISH_BOOT_START; /* ISH SRAM (640KB) begins at 0xFF000000 */
+
+	/* .init section should be first, since it contains the boot code */
+	.init : { *(.init*); }
+	.text : { *(.text.*); }
+	.text.unlikely : { *(.text.unlikely*); }
+
+	. = ALIGN(4);
+	.rodata : {
+		/* Symbols defined here are declared in link_defs.h */
+		 __irqprio = .;
+	        KEEP(*(.rodata.irqprio))
+		 __irqprio_end = .;
+
+		 __irq_data = .;
+	        KEEP(*(.rodata.irqs))
+		 __irq_data_end = .;
+
+		. = ALIGN(4);
+		 __cmds = .;
+		 KEEP(*(SORT(.rodata.cmds*)))
+		 __cmds_end = .;
+
+		 . = ALIGN(4);
+		 __extension_cmds = .;
+		 KEEP(*(.rodata.extensioncmds))
+		 __extension_cmds_end = .;
+
+		 . = ALIGN(4);
+		 __hcmds = .;
+		 KEEP(*(.rodata.hcmds))
+		 __hcmds_end = .;
+
+		 . = ALIGN(4);
+		 __mkbp_evt_srcs = .;
+		 KEEP(*(.rodata.evtsrcs))
+		 __mkbp_evt_srcs_end = .;
+
+		 . = ALIGN(4);
+		__hooks_init = .;
+		KEEP(*(.rodata.HOOK_INIT))
+		__hooks_init_end = .;
+
+		__hooks_pre_freq_change = .;
+		KEEP(*(.rodata.HOOK_PRE_FREQ_CHANGE))
+		__hooks_pre_freq_change_end = .;
+
+		__hooks_freq_change = .;
+		KEEP(*(.rodata.HOOK_FREQ_CHANGE))
+		__hooks_freq_change_end = .;
+
+		__hooks_sysjump = .;
+		KEEP(*(.rodata.HOOK_SYSJUMP))
+		__hooks_sysjump_end = .;
+
+		__hooks_chipset_pre_init = .;
+		KEEP(*(.rodata.HOOK_CHIPSET_PRE_INIT))
+		__hooks_chipset_pre_init_end = .;
+
+		__hooks_chipset_startup = .;
+		KEEP(*(.rodata.HOOK_CHIPSET_STARTUP))
+		__hooks_chipset_startup_end = .;
+
+		__hooks_chipset_resume = .;
+		KEEP(*(.rodata.HOOK_CHIPSET_RESUME))
+		__hooks_chipset_resume_end = .;
+
+		__hooks_chipset_suspend = .;
+		KEEP(*(.rodata.HOOK_CHIPSET_SUSPEND))
+		__hooks_chipset_suspend_end = .;
+
+		__hooks_chipset_shutdown = .;
+		KEEP(*(.rodata.HOOK_CHIPSET_SHUTDOWN))
+		__hooks_chipset_shutdown_end = .;
+
+		__hooks_chipset_reset = .;
+		KEEP(*(.rodata.HOOK_CHIPSET_RESET))
+		__hooks_chipset_reset_end = .;
+
+		__hooks_ac_change = .;
+		KEEP(*(.rodata.HOOK_AC_CHANGE))
+		__hooks_ac_change_end = .;
+
+		__hooks_lid_change = .;
+		KEEP(*(.rodata.HOOK_LID_CHANGE))
+		__hooks_lid_change_end = .;
+
+		__hooks_pwrbtn_change = .;
+		KEEP(*(.rodata.HOOK_POWER_BUTTON_CHANGE))
+		__hooks_pwrbtn_change_end = .;
+
+		__hooks_charge_state_change = .;
+		KEEP(*(.rodata.HOOK_CHARGE_STATE_CHANGE))
+		__hooks_charge_state_change_end = .;
+
+		__hooks_battery_soc_change = .;
+		KEEP(*(.rodata.HOOK_BATTERY_SOC_CHANGE))
+		__hooks_battery_soc_change_end = .;
+
+		__hooks_tick = .;
+		KEEP(*(.rodata.HOOK_TICK))
+		__hooks_tick_end = .;
+
+		__hooks_second = .;
+		KEEP(*(.rodata.HOOK_SECOND))
+		__hooks_second_end = .;
+
+		__deferred_funcs = .;
+		KEEP(*(.rodata.deferred))
+		__deferred_funcs_end = .;
+
+		 . = ALIGN(4);
+		 KEEP(*(.rodata.*))
+	}
+
+	.data : {
+		 __data_start = .;
+		*(.data.*);
+		 __data_end = .;
+	 }
+
+	. = ALIGN(4);
+	.note.gnu.build-id : { *(.note.gnu.build-id); }
+
+	.bss : {
+		__bss_start = .;
+
+		*(.bss*);
+		*(COMMON*);
+
+		# Reserve space for deferred function firing times.  Each time
+		# is a uint64_t, each func is a 32-bit pointer, thus the scaling
+		# factor of two.  The 8 byte alignment of uint64_t is required
+		# by the ABI.
+
+		 . = ALIGN(8);
+		 __deferred_until = .;
+		 . += (__deferred_funcs_end - __deferred_funcs) * (8 / 4);
+		 __deferred_until_end = .;
+
+		 __bss_end = .;
+		__bss_size_words = (__bss_end - __bss_start) / 4;
+	}
+
+	def_irq_low  = ABSOLUTE(default_int_handler) & 0xFFFF;
+	def_irq_high = ABSOLUTE(default_int_handler) >> 16;
+}
--- a/core/minute-ia/include/math.h
+++ b/core/minute-ia/include/math.h
@@ -0,0 +1,37 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Math utility functions for minute-IA */
+
+#ifndef __CROS_EC_MATH_H
+#define __CROS_EC_MATH_H
+
+#ifdef CONFIG_FPU
+static inline float sqrtf(float v)
+{
+	float root;
+
+	asm volatile(
+		"fsqrt %0, %1"
+		: "=w" (root)
+		: "w" (v)
+	);
+	return root;
+}
+
+static inline float fabsf(float v)
+{
+	float root;
+
+	asm volatile(
+		"fabs %0, %1"
+		: "=w" (root)
+		: "w" (v)
+	);
+	return root;
+}
+#endif  /* CONFIG_FPU */
+
+#endif  /* __CROS_EC_MATH_H */
--- a/core/minute-ia/init.S
+++ b/core/minute-ia/init.S
@@ -0,0 +1,334 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * ISH minute-IA CPU initialization
+ */
+
+#include "config.h"
+#include "interrupts.h"
+
+.global __idt
+
+# GDT is loaded by ISH ROM. The FW code retains the same GDT
+# and hence the same segment selector
+.set code_seg, 0x8
+
+.section .text.vecttable
+
+# Macro that defines an interrupt descriptor
+.macro interrupt_descriptor
+	.word def_irq_low	# low 16 bits of default_int_handler
+	.word code_seg
+	.byte 0
+	.byte IDT_FLAGS
+	.word def_irq_high	# high 16 bits of default_int_handler
+.endm
+
+.align 32
+# Static Interrupt descriptor table (vectors 0-255), all vectors initialized
+# to default_int_handler. DECLARE_IRQ() remaps to the appropriate handler.
+__idt:
+interrupt_descriptor		#  0 - Divide error
+interrupt_descriptor		#  1 - Debug
+interrupt_descriptor		#  2 - NMI interrupt
+interrupt_descriptor		#  3 - Breakpoint
+interrupt_descriptor		#  4 - Overflow
+interrupt_descriptor		#  5 - Bound range exceeded
+interrupt_descriptor		#  6 - Invalid opcode
+interrupt_descriptor		#  7 - Device not available
+interrupt_descriptor		#  8 - Double fault
+interrupt_descriptor		#  9 - Coprocessor overrun
+interrupt_descriptor		# 10 - Invalid TSS
+interrupt_descriptor		# 11 - Segment not present
+interrupt_descriptor		# 12 - Stack segment fault
+interrupt_descriptor		# 13 - General protection
+interrupt_descriptor		# 14 - Page fault
+interrupt_descriptor		# 15 - Reserved
+interrupt_descriptor		# 16 - Floating point error
+interrupt_descriptor		# 17 - Alignment check
+interrupt_descriptor		# 18 - Machine check
+interrupt_descriptor		# 19 - SIMD floating-point exception
+interrupt_descriptor		# 20 - Virtualization exception
+interrupt_descriptor		# 21..31 - Reserved
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor		# 32..255 - User-defined, Maskable Interrupts
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor		# 64
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor		# 96
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor		# 128
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor		# 160
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor		# 192
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor		# 224
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor
+interrupt_descriptor		# 255
+
+#.section .data
+__idt_ptr:
+	.word 2047	# Table size in bytes, count from 0
+			# (8N - 1). N = 256 - the number of vectors
+	.long __idt	# Base address of IDT
+
+
+.section .init
+.code32
+
+# The .init section is mapped to linear address 0xFF000000, the SRAM start.
+# ISH BUP (bring-up) downloads ISH FW to ISH SRAM and jumps to start address.
+.global reset
+
+# Entry point - core is already set to 32-bit linear mode by ISH ROM
+reset:
+
+	# Disabling interrupts initially. It will be enabled when tasks start
+	cli
+
+	# Clear .bss section.
+	xorl %eax, %eax
+	cld
+	movl $__bss_start, %edi
+	movl $__bss_size_words, %ecx
+	rep stosl
+
+	# System stack is within .bss, already cleared
+	movl $stack_end, %esp
+
+	# Load IDT
+	lidt __idt_ptr
+
+#ifdef CONFIG_FPU
+	fninit
+#endif
+
+	# Jump to C code
+	jmp main
+
+# Reserve space for system stack
+.section .bss.system_stack
+stack_start:
+.space CONFIG_STACK_SIZE, 0
+stack_end:
+.global stack_end
--- a/core/minute-ia/interrupts.c
+++ b/core/minute-ia/interrupts.c
@@ -0,0 +1,150 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Set up the LM2 mIA core & interrupts
+ */
+
+#include "common.h"
+#include "util.h"
+#include "interrupts.h"
+#include "registers.h"
+#include "task_defs.h"
+#include "irq_handler.h"
+#include "console.h"
+
+/* Console output macros */
+#define CPUTS(outstr) cputs(CC_SYSTEM, outstr)
+#define CPRINTF(format, args...) cprintf(CC_SYSTEM, format, ## args)
+#define CPRINTS(format, args...) cprints(CC_SYSTEM, format, ## args)
+
+/* The IDT  - initialized in init.S */
+extern IDT_entry __idt[NUM_VECTORS];
+
+/* To count the interrupt nesting depth. Usually it is not nested */
+volatile uint32_t __in_isr;
+
+void write_ioapic_reg(const uint32_t reg, const uint32_t val)
+{
+	REG32(IOAPIC_IDX) = (uint8_t)reg;
+	REG32(IOAPIC_WDW) = val;
+}
+
+uint32_t read_ioapic_reg(const uint32_t reg)
+{
+	REG32(IOAPIC_IDX) = (uint8_t)reg;
+	return REG32(IOAPIC_WDW);
+}
+
+void set_ioapic_redtbl_raw(const unsigned irq, const uint32_t val)
+{
+	const uint32_t redtbl_lo = IOAPIC_IOREDTBL + 2 * irq;
+	const uint32_t redtbl_hi = redtbl_lo + 1;
+
+	write_ioapic_reg(redtbl_lo, val);
+	write_ioapic_reg(redtbl_hi, DEST_APIC_ID);
+}
+
+void unmask_interrupt(uint32_t irq)
+{
+	uint32_t val;
+	const uint32_t redtbl_lo = IOAPIC_IOREDTBL + 2 * irq;
+
+	val = read_ioapic_reg(redtbl_lo);
+	val &= ~IOAPIC_REDTBL_MASK;
+	set_ioapic_redtbl_raw(irq, val);
+}
+
+void mask_interrupt(uint32_t irq)
+{
+	uint32_t val;
+	const uint32_t redtbl_lo = IOAPIC_IOREDTBL + 2 * irq;
+
+	val = read_ioapic_reg(redtbl_lo);
+	val |= IOAPIC_REDTBL_MASK;
+	set_ioapic_redtbl_raw(irq, val);
+}
+
+/* Maps IRQs to vectors. To be programmed in IOAPIC redirection table */
+static const irq_desc_t system_irqs[] = {
+	LEVEL_INTR(ISH30_I2C0_IRQ, ISH30_I2C0_VEC),
+	LEVEL_INTR(ISH30_I2C1_IRQ, ISH30_I2C1_VEC),
+	LEVEL_INTR(ISH30_I2C2_IRQ, ISH30_I2C2_VEC),
+	LEVEL_INTR(ISH30_IPC_HOST2ISH_IRQ, ISH30_IPC_VEC),
+	LEVEL_INTR(ISH30_HPET_TIMER0_IRQ, ISH30_HPET_TIMER0_VEC),
+	LEVEL_INTR(ISH30_HPET_TIMER1_IRQ, ISH30_HPET_TIMER1_VEC),
+};
+
+
+void set_interrupt_gate(uint8_t num, isr_handler_t func, uint8_t flags)
+{
+	uint16_t code_segment;
+	uint32_t base = (uint32_t) func;
+
+	__idt[num].ISR_low = (uint16_t) (base & USHRT_MAX);
+	__idt[num].ISR_high = (uint16_t) ((base >> 16UL) & USHRT_MAX);
+
+	/* When the flat model is used the CS will never change. */
+	__asm volatile ("mov %%cs, %0":"=r" (code_segment));
+	__idt[num].segment_selector = code_segment;
+	__idt[num].zero = 0;
+	__idt[num].flags = flags;
+}
+
+void unhandled_vector(void)
+{
+	uint32_t vec = 0xff, i;
+	uint32_t ioapic_icr_last = LAPIC_ISR_REG; /* In service register */
+
+	/* Scan ISRs */
+	for (i = 7; i >= 0; i--, ioapic_icr_last -= 0x10) {
+
+		asm("movl (%1), %0\n" : "=&r" (vec) : "r" (ioapic_icr_last));
+		if (vec) {
+			vec = (32 * __fls(vec)) + i;
+			break;
+		}
+	}
+
+	CPRINTF("Ignoring vector 0x%0x!\n", vec);
+	asm("" : : "a" (vec));
+}
+
+/* This needs to be moved to link_defs.h */
+extern const struct irq_data __irq_data[], __irq_data_end[];
+
+void init_interrupts(void)
+{
+	unsigned entry;
+	const struct irq_data *p = __irq_data;
+	unsigned num_system_irqs = ARRAY_SIZE(system_irqs);
+	unsigned max_entries = (read_ioapic_reg(IOAPIC_VERSION) >> 16) & 0xff;
+
+	/* Setup gates for IRQs declared by drivers using DECLARE_IRQ */
+	for (; p < __irq_data_end; p++)
+		set_interrupt_gate(IRQ_TO_VEC(p->irq), p->routine, IDT_FLAGS);
+
+	/* Mask all interrupts by default in IOAPIC */
+	for (entry = 0; entry < max_entries; entry++)
+		set_ioapic_redtbl_raw(entry, IOAPIC_REDTBL_MASK);
+
+	/* Enable pre-defined interrupts */
+	for (entry = 0; entry < num_system_irqs; entry++)
+		set_ioapic_redtbl_raw(system_irqs[entry].irq,
+				      system_irqs[entry].vector |
+				      IOAPIC_REDTBL_DELMOD_FIXED |
+				      IOAPIC_REDTBL_DESTMOD_PHYS |
+				      IOAPIC_REDTBL_MASK |
+				      system_irqs[entry].polarity |
+				      system_irqs[entry].trigger);
+
+	set_interrupt_gate(ISH_TS_VECTOR, __switchto, IDT_FLAGS);
+
+	/* Note: At reset, ID field is already set to 0 in APIC ID register */
+
+	/* Enable the APIC, mapping the spurious interrupt at the same time. */
+	APIC_SPURIOUS_INT = LAPIC_SPURIOUS_INT_VECTOR | APIC_ENABLE_BIT;
+
+	/* Set timer error vector. */
+	APIC_LVT_ERROR = LAPIC_LVT_ERROR_VECTOR;
+}
--- a/core/minute-ia/interrupts.h
+++ b/core/minute-ia/interrupts.h
@@ -0,0 +1,72 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Registers map and defintions for mIA LM2 processor
+ */
+
+#ifndef __CROS_EC_IA32_INTERRUPTS_H
+#define __CROS_EC_IA32_INTERRUPTS_H
+
+#ifndef __ASSEMBLER__
+#include <stdint.h>
+
+#define USHRT_MAX		0xFFFF
+typedef struct {
+	unsigned irq;
+	unsigned trigger;
+	unsigned polarity;
+	unsigned vector;
+} irq_desc_t;
+
+#define INTR_DESC(__irq,__vector,__trig)                    \
+    {                                                       \
+        .irq            = __irq,                            \
+        .trigger        = __trig,                           \
+        .polarity       = IOAPIC_REDTBL_INTPOL_HIGH,        \
+        .vector         = __vector	                    \
+    }
+
+#define LEVEL_INTR(__irq, __vector) \
+	INTR_DESC(__irq, __vector, IOAPIC_REDTBL_TRIGGER_LEVEL)
+#define EDGE_INTR(__irq, __vector) \
+	INTR_DESC(__irq, __vector, IOAPIC_REDTBL_TRIGGER_EDGE)
+#endif
+
+/* ISH has a single core processor */
+#define DEST_APIC_ID			0
+#define NUM_VECTORS			256
+
+/* Default flags setting for entries in the IDT.
+ * 7	- Present bit
+ * 6:5	- Descriptor privilage level
+ * 4	- Storage segment (0 for interrupt gate)
+ * 3:0	- Gate type (1110 = Interrupt gate)
+ */
+#define IDT_FLAGS			0x8E
+
+/* APIC bit definitions. */
+#define APIC_DIV_16			0x03
+#define APIC_ENABLE_BIT			(1UL << 8UL)
+#define APIC_SPURIOUS_INT		REG32(LAPIC_BASE + 0xF0UL )
+#define APIC_LVT_ERROR			REG32(LAPIC_BASE + 0x370UL)
+
+#ifndef __ASSEMBLER__
+/* Interrupt descriptor entry */
+struct IDT_entry_t {
+	uint16_t ISR_low;	/* Low 16 bits of handler address. */
+	uint16_t segment_selector;	/* Flat model means this is not changed. */
+	uint8_t zero;		/* Must be set to zero. */
+	uint8_t flags;		/* Flags for this entry. */
+	uint16_t ISR_high;	/* High 16 bits of handler address. */
+} __attribute__ ((packed));
+typedef struct IDT_entry_t IDT_entry;
+
+typedef void (*isr_handler_t) (void);
+
+void init_interrupts(void);
+void mask_interrupt(unsigned int irq);
+void unmask_interrupt(unsigned int irq);
+#endif
+
+#endif	/* __CROS_EC_IA32_INTERRUPTS_H */
--- a/core/minute-ia/irq_handler.h
+++ b/core/minute-ia/irq_handler.h
@@ -0,0 +1,62 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Helper to declare IRQ handling routines */
+
+#ifndef __CROS_EC_IRQ_HANDLER_H
+#define __CROS_EC_IRQ_HANDLER_H
+
+#include "registers.h"
+
+struct irq_data {
+	void (*routine)(void);
+	int irq;
+};
+
+/* Helper macros to build the IRQ handler and priority struct names */
+#define IRQ_HANDLER(irqname) CONCAT3(_irq_, irqname, _handler)
+#define IRQ_PRIORITY(irqname) CONCAT2(prio_, irqname)
+/*
+ * Macro to connect the interrupt handler "routine" to the irq number "irq" and
+ * ensure it is enabled in the interrupt controller with the right priority.
+ *
+ * Note: No 'naked' function support for x86, so function is implemented within
+ * __asm__
+ */
+#define DECLARE_IRQ(irq, routine) DECLARE_IRQ_(irq, routine, irq + 32 + 10)
+/* Each irq has a irq_data structure placed in .rodata.irqs section,
+ * to be used for dynamically setting up interrupt gates */
+#define DECLARE_IRQ_(irq, routine, vector)				\
+	void __keep routine(void);					\
+	void IRQ_HANDLER(irq)(void); 					\
+	__asm__ (".section .rodata.irqs\n");				\
+	const struct irq_data __keep CONCAT4(__irq_, irq, _, routine)	\
+	__attribute__((section(".rodata.irqs")))= {IRQ_HANDLER(irq), irq};\
+	__asm__ (							\
+		".section .text._irq_"#irq"_handler\n"			\
+		"_irq_"#irq"_handler:\n"				\
+			"pusha\n"					\
+			"add  $1, __in_isr\n"				\
+			"call "#routine"\n"				\
+			"push $0\n"					\
+			"push $0\n"					\
+			"call switch_handler\n"				\
+			"addl $0x08, %esp\n"				\
+			"test %eax, %eax\n"				\
+			"je 1f\n"					\
+			"movl current_task, %eax\n"			\
+			"movl %esp, (%eax)\n"				\
+			"movl next_task, %eax\n"			\
+			"movl %eax, current_task\n"			\
+			"movl (%eax), %esp\n"				\
+			"1:\n"						\
+			"movl $"#vector ", (0xFEC00040)\n"              \
+			"sub  $1, __in_isr\n"				\
+			"movl $0x00, (0xFEE000B0)\n" 			\
+			"popa\n"					\
+			"iret\n"					\
+		);
+
+#endif  /* __CROS_EC_IRQ_HANDLER_H */
--- a/core/minute-ia/mpu.c
+++ b/core/minute-ia/mpu.c
@@ -0,0 +1,17 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* MPU module for ISH */
+
+#include "mpu.h"
+#include "console.h"
+#include "registers.h"
+#include "task.h"
+#include "util.h"
+
+int mpu_pre_init(void)
+{
+	return EC_SUCCESS;
+}
--- a/core/minute-ia/panic.c
+++ b/core/minute-ia/panic.c
@@ -0,0 +1,72 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "common.h"
+#include "console.h"
+#include "cpu.h"
+#include "host_command.h"
+#include "panic.h"
+#include "printf.h"
+#include "system.h"
+#include "task.h"
+#include "timer.h"
+#include "util.h"
+#include "watchdog.h"
+
+/* Whether bus fault is ignored */
+static int bus_fault_ignored;
+
+/* Panic data goes at the end of RAM. */
+static struct panic_data * const pdata_ptr = PANIC_DATA_PTR;
+
+/* Preceded by stack, rounded down to nearest 64-bit-aligned boundary */
+static const uint32_t pstack_addr = (CONFIG_RAM_BASE + CONFIG_RAM_SIZE
+				     - sizeof(struct panic_data)) & ~7;
+
+/*
+ * Print panic data
+ */
+void panic_data_print(const struct panic_data *pdata)
+{
+}
+
+void __keep report_panic(void)
+{
+}
+
+/**
+ * Default exception handler, which reports a panic.
+ *
+ * Declare this as a naked call so we can extract raw LR and IPSR values.
+ */
+void __keep exception_panic(void);
+void exception_panic(void)
+{
+}
+
+#ifdef CONFIG_SOFTWARE_PANIC
+void software_panic(uint32_t reason, uint32_t info)
+{
+}
+
+void panic_set_reason(uint32_t reason, uint32_t info, uint8_t exception)
+{
+}
+
+void panic_get_reason(uint32_t *reason, uint32_t *info, uint8_t *exception)
+{
+}
+#endif
+
+void bus_fault_handler(void)
+{
+	if (!bus_fault_ignored)
+		exception_panic();
+}
+
+void ignore_bus_fault(int ignored)
+{
+	bus_fault_ignored = ignored;
+}
--- a/core/minute-ia/switch.S
+++ b/core/minute-ia/switch.S
@@ -0,0 +1,110 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * x86 task swtching and interrupt handling
+ */
+
+#include "config.h"
+#include "registers.h"
+#include "task_defs.h"
+
+.text
+
+.extern current_task
+.extern next_task
+
+.global __task_start
+.global __switchto
+.global default_int_handler
+
+# Start the task scheduling. Start current_task (hook_task)
+# This function is not an ISR but imitates the sequence.
+.align 4
+.func __task_start
+__task_start:
+	movl current_task, %eax
+	movl (%eax), %esp
+	popa
+	iret
+.endfunc
+
+# Default interrupt handler - to handle exceptions
+# and prints error
+.align 4
+.func default_int_handler
+default_int_handler:
+
+	pusha
+	add $1, __in_isr
+
+	call unhandled_vector		# Handle system interrupts and
+					# unregistered user interrupts
+
+	cmpl $LAPIC_SPURIOUS_INT_VECTOR, %eax
+	je 1f				# No EOI for LAPIC_SPURIOUS_INT_VECTOR
+
+	movl %eax, IOAPIC_EOI_REG	# Indicate completion of servicing the
+					# interrupt to IOAPIC first
+	sub $1, __in_isr
+	movl $0x00, LAPIC_EOI_REG	# Indicate completion of servicing the
+					# interrupt to LAPIC next
+	1:
+	popa
+	iret
+
+.endfunc
+
+# Switches from one task to another if ready.
+# __schedule triggeres software interrupt ISH_TS_VECTOR, which is handled by
+# __switchto
+.align 4
+.func __switchto
+__switchto:
+
+	# Save current task
+	pusha
+	addl $1, __in_isr
+
+	# __schedule() copies 'resched' to %ecx and 'desched' to %edx before
+	# triggering ISH_TS_VECTOR
+	#
+	# Push %ecx and %edx into stack to pass them as function parameters
+	# to switch_handler(desched, resched)
+
+	push %ecx
+	push %edx
+	call switch_handler
+	addl $0x8, %esp		# Clean up stack
+
+	test %eax, %eax		# Check if task switch required
+	jz 1f
+
+	movl current_task, %eax
+
+#ifdef CONFIG_FPU
+	fnsave 20(%eax)		# Save current FPU context at current->fp_ctx
+#endif
+
+	# Save SP of current task and switch to new task
+	movl %esp, (%eax)
+	movl next_task, %eax
+	movl %eax, current_task
+	movl (%eax), %esp
+
+#ifdef CONFIG_FPU
+	frstor 20(%eax)		# Restore next FPU context
+#endif
+
+	1:
+	subl $1, __in_isr
+
+	# Indicate completion of servicing the interrupt to LAPIC.
+	# No IOAPIC EOI needed as this is SW triggered.
+	movl $0x00, LAPIC_EOI_REG
+
+	# Restore general purpose registers.
+	popa
+	iret
+
+.endfunc
--- a/core/minute-ia/task.c
+++ b/core/minute-ia/task.c
@@ -0,0 +1,679 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Task scheduling / events module for Chrome EC operating system */
+
+#include "atomic.h"
+#include "common.h"
+#include "console.h"
+#include "link_defs.h"
+#include "panic.h"
+#include "task.h"
+#include "timer.h"
+#include "util.h"
+#include "task_defs.h"
+#include "interrupts.h"
+#include "ipc.h"
+#include "hpet.h"
+
+/* Console output macros */
+#define CPUTS(outstr) cputs(CC_SYSTEM, outstr)
+#define CPRINTF(format, args...) cprintf(CC_SYSTEM, format, ## args)
+#define CPRINTS(format, args...) cprints(CC_SYSTEM, format, ## args)
+
+/* Value to store in unused stack */
+#define STACK_UNUSED_VALUE 0xdeadd00d
+
+/* declare task routine prototypes */
+#define TASK(n, r, d, s) int r(void *);
+void __idle(void);
+CONFIG_TASK_LIST
+CONFIG_TEST_TASK_LIST
+#undef TASK
+
+/* This is set by interrupt handlers */
+extern volatile uint32_t __in_isr;
+
+/* Task names for easier debugging */
+#define TASK(n, r, d, s)  #n,
+static const char * const task_names[] = {
+	"<< idle >>",
+	CONFIG_TASK_LIST
+	CONFIG_TEST_TASK_LIST
+};
+#undef TASK
+
+#ifdef CONFIG_TASK_PROFILING
+static uint64_t task_start_time; /* Time task scheduling started */
+static uint64_t exc_start_time;  /* Time of task->exception transition */
+static uint64_t exc_end_time;    /* Time of exception->task transition */
+static uint64_t exc_total_time;  /* Total time in exceptions */
+static uint32_t svc_calls;	 /* Number of service calls */
+static uint32_t task_switches;	/* Number of times active task changed */
+static uint32_t irq_dist[CONFIG_IRQ_COUNT];	/* Distribution of IRQ calls */
+#endif
+
+void __schedule(int desched, int resched);
+
+#ifndef CONFIG_LOW_POWER_IDLE
+/* Idle task.  Executed when no tasks are ready to be scheduled. */
+void __idle(void)
+{
+	uint32_t idelay = 1000;
+
+	while (1) {
+		/*
+		 * Wait for the next irq event.  This stops the CPU clock
+		 * (sleep / deep sleep, depending on chip config).
+		 *
+		 * Todo - implement sleep instead of delay
+		 */
+		udelay(idelay);
+	}
+}
+
+#endif /* !CONFIG_LOW_POWER_IDLE */
+
+static void task_exit_trap(void)
+{
+	int i = task_get_current();
+
+	cprints(CC_TASK, "Task %d (%s) exited!", i, task_names[i]);
+	/* Exited tasks simply sleep forever */
+	while (1)
+		task_wait_event(-1);
+}
+
+/* Startup parameters for all tasks. */
+#define TASK(n, r, d, s)  {	\
+	.r0 = (uint32_t)d,	\
+	.pc = (uint32_t)r,	\
+	.stack_size = s,	\
+},
+static const struct {
+	uint32_t r0;
+	uint32_t pc;
+	uint16_t stack_size;
+} const tasks_init[] = {
+	TASK(IDLE, __idle, 0, IDLE_TASK_STACK_SIZE)
+	CONFIG_TASK_LIST
+	CONFIG_TEST_TASK_LIST
+};
+
+#undef TASK
+
+/* Contexts for all tasks */
+static task_ tasks[TASK_ID_COUNT];
+/* Sanity checks about static task invariants */
+BUILD_ASSERT(TASK_ID_COUNT <= sizeof(unsigned) * 8);
+BUILD_ASSERT(TASK_ID_COUNT < (1 << (sizeof(task_id_t) * 8)));
+
+
+/* Stacks for all tasks */
+#define TASK(n, r, d, s)  + s
+uint8_t task_stacks[0
+		    TASK(IDLE, __idle, 0, IDLE_TASK_STACK_SIZE)
+		    CONFIG_TASK_LIST
+		    CONFIG_TEST_TASK_LIST
+] __aligned(8);
+
+#undef TASK
+
+
+task_ *current_task, *next_task;
+/*
+ * Should IRQs chain to switch_handler()?  This should be set if either of the
+ * following is true:
+ *
+ * 1) Task scheduling has started, and task profiling is enabled.  Task
+ * profiling does its tracking in switch_handler().
+ *
+ * 2) An event was set by an interrupt; this could result in a higher-priority
+ * task unblocking.  After checking for a task switch, switch_handler() will
+ * clear  the flag (unless profiling is also enabled; then the flag remains
+ * set).
+ */
+static int need_resched_or_profiling;
+
+/*
+ * Bitmap of all tasks ready to be run.
+ *
+ * Start off with only the hooks task marked as ready such that all the modules
+ * can do their init within a task switching context.  The hooks task will then
+ * make a call to enable all tasks.
+ */
+static uint32_t tasks_ready = (1 << TASK_ID_HOOKS);
+
+static int start_called;  /* Has task swapping started */
+
+static inline task_ *__task_id_to_ptr(task_id_t id)
+{
+	return tasks + id;
+}
+
+void interrupt_disable(void)
+{
+	__asm__ __volatile__ ("cli");
+}
+
+void interrupt_enable(void)
+{
+	__asm__ __volatile__ ("sti");
+}
+
+inline int in_interrupt_context(void)
+{
+	return !!__in_isr;
+}
+
+inline int get_interrupt_context(void)
+{
+	return 0;
+}
+
+task_id_t task_get_current(void)
+{
+#ifdef CONFIG_DEBUG_BRINGUP
+	/* If we haven't done a context switch then our task ID isn't valid */
+	ASSERT(task_start_called() != 1);
+#endif
+	return current_task - tasks;
+}
+
+uint32_t *task_get_event_bitmap(task_id_t tskid)
+{
+	task_ *tsk = __task_id_to_ptr(tskid);
+
+	return &tsk->events;
+}
+
+int task_start_called(void)
+{
+	return start_called;
+}
+
+/**
+ * Scheduling system call
+ */
+uint32_t switch_handler(int desched, task_id_t resched)
+{
+	task_ *current, *next;
+#ifdef CONFIG_TASK_PROFILING
+	int exc = get_interrupt_context();
+	uint64_t t;
+#endif
+
+
+#ifdef CONFIG_TASK_PROFILING
+	/*
+	 * SVCall isn't triggered via DECLARE_IRQ(), so it needs to track its
+	 * start time explicitly.
+	 */
+	if (exc == 0xb) {
+		exc_start_time = get_time().val;
+		svc_calls++;
+	}
+#endif
+
+	/* Stay in hook till task_enable_all_tasks() */
+	if (!task_start_called() && tasks_ready > 3)
+		tasks_ready = 3;
+
+	current = current_task;
+
+#ifdef CONFIG_DEBUG_STACK_OVERFLOW
+	if (*current->stack != STACK_UNUSED_VALUE) {
+		panic_printf("\n\nStack overflow in %s task!\n",
+				task_names[current - tasks]);
+#ifdef CONFIG_SOFTWARE_PANIC
+		software_panic(PANIC_SW_STACK_OVERFLOW, current - tasks);
+#endif
+	}
+#endif
+
+	if (desched && !current->events) {
+		/*
+		 * Remove our own ready bit (current - tasks is same as
+		 * task_get_current())
+		 */
+		tasks_ready &= ~(1 << (current - tasks));
+	}
+	tasks_ready |= 1 << resched;
+
+	ASSERT(tasks_ready);
+	next = __task_id_to_ptr(__fls(tasks_ready));
+
+#ifdef CONFIG_TASK_PROFILING
+	/* Track time in interrupts */
+	t = get_time().val;
+	exc_total_time += (t - exc_start_time);
+
+	/*
+	 * Bill the current task for time between the end of the last interrupt
+	 * and the start of this one.
+	 */
+	current->runtime += (exc_start_time - exc_end_time);
+	exc_end_time = t;
+#else
+	/*
+	 * Don't chain here from interrupts until the next time an interrupt
+	 * sets an event.
+	 */
+	need_resched_or_profiling = 0;
+#endif
+
+	/* Nothing to do */
+	if (next == current)
+		return 0;
+
+#ifdef ISH_DEBUG
+	CPRINTF("[%d -> %d]\n", current - tasks, next - tasks);
+#endif
+
+	/* Switch to new task */
+#ifdef CONFIG_TASK_PROFILING
+	task_switches++;
+#endif
+	next_task = next;
+
+	/* TS required */
+	return 1;
+}
+
+void __schedule(int desched, int resched)
+{
+	__asm__ __volatile__ ("int %0"
+			:
+			: "i" (ISH_TS_VECTOR),
+			  "d" (desched), "c" (resched)
+			);
+}
+
+#ifdef CONFIG_TASK_PROFILING
+void __keep task_start_irq_handler(void *excep_return)
+{
+	/*
+	 * Get time before checking depth, in case this handler is
+	 * pre-empted.
+	 */
+	uint64_t t = get_time().val;
+	int irq = get_interrupt_context() - 16;
+
+	/*
+	 * Track IRQ distribution.  No need for atomic add, because an IRQ
+	 * can't pre-empt itself.
+	 */
+	if (irq < ARRAY_SIZE(irq_dist))
+		irq_dist[irq]++;
+
+	/*
+	 * Continue iff a rescheduling event happened or profiling is active,
+	 * and we are not called from another exception (this must match the
+	 * logic for when we chain to svc_handler() below).
+	 */
+	if (!need_resched_or_profiling || (((uint32_t)excep_return & 0xf) == 1))
+		return;
+
+	exc_start_time = t;
+}
+#endif
+
+void __keep task_resched_if_needed(void *excep_return)
+{
+	/*
+	 * Continue iff a rescheduling event happened or profiling is active,
+	 * and we are not called from another exception.
+	 */
+	if (!need_resched_or_profiling || (((uint32_t)excep_return & 0xf) == 1))
+		return;
+
+	switch_handler(0, 0);
+}
+
+static uint32_t __wait_evt(int timeout_us, task_id_t resched)
+{
+	task_ *tsk = current_task;
+	task_id_t me = tsk - tasks;
+	uint32_t evt;
+	int ret __attribute__((unused));
+
+	ASSERT(!in_interrupt_context());
+
+	if (timeout_us > 0) {
+		timestamp_t deadline = get_time();
+
+		deadline.val += timeout_us;
+		ret = timer_arm(deadline, me);
+		ASSERT(ret == EC_SUCCESS);
+	}
+	while (!(evt = atomic_read_clear(&tsk->events))) {
+		/* Remove ourself and get the next task in the scheduler */
+		__schedule(1, resched);
+		resched = TASK_ID_IDLE;
+	}
+	if (timeout_us > 0)
+		timer_cancel(me);
+	return evt;
+}
+
+uint32_t task_set_event(task_id_t tskid, uint32_t event, int wait)
+{
+	task_ *receiver = __task_id_to_ptr(tskid);
+
+	if (tskid > TASK_ID_COUNT) {
+		receiver = current_task;
+		tskid = receiver - tasks;
+	} else {
+		receiver = __task_id_to_ptr(tskid);
+	}
+
+	ASSERT(receiver);
+
+	/* Set the event bit in the receiver message bitmap */
+	atomic_or(&receiver->events, event);
+
+	/* Re-schedule if priorities have changed */
+	if (in_interrupt_context()) {
+		/* The receiver might run again */
+		atomic_or(&tasks_ready, 1 << tskid);
+#ifndef CONFIG_TASK_PROFILING
+		if (start_called)
+			need_resched_or_profiling = 1;
+#endif
+	} else {
+		if (wait)
+			return __wait_evt(-1, tskid);
+		else
+			__schedule(0, tskid);
+	}
+
+	return 0;
+}
+
+uint32_t task_wait_event(int timeout_us)
+{
+	return __wait_evt(timeout_us, TASK_ID_IDLE);
+}
+
+uint32_t task_wait_event_mask(uint32_t event_mask, int timeout_us)
+{
+	uint64_t deadline = get_time().val + timeout_us;
+	uint32_t events = 0;
+	int time_remaining_us = timeout_us;
+
+	/* Add the timer event to the mask so we can indicate a timeout */
+	event_mask |= TASK_EVENT_TIMER;
+
+	while (!(events & event_mask)) {
+		/* Collect events to re-post later */
+		events |= __wait_evt(time_remaining_us, TASK_ID_IDLE);
+
+		time_remaining_us = deadline - get_time().val;
+		if (timeout_us > 0 && time_remaining_us <= 0) {
+			/* Ensure we return a TIMER event if we timeout */
+			events |= TASK_EVENT_TIMER;
+			break;
+		}
+	}
+
+	/* Re-post any other events collected */
+	if (events & ~event_mask)
+		atomic_or(&current_task->events, events & ~event_mask);
+
+	return events & event_mask;
+}
+
+void task_enable_all_tasks(void)
+{
+	/* Mark all tasks as ready to run. */
+	tasks_ready = (1 << TASK_ID_COUNT) - 1;
+
+	start_called = 1;
+
+	/* The host OS driver should wait till the FW completes all hook inits.
+	 * Otherwise, FW may fail to respond to host commands or crash when
+	 * not fully initialized. This MNG (management) type IPC message sent
+	 * asynchronously from the FW indicates completion of initialization.
+	 */
+	CPUTS("*** MNG FW ready ****\n");
+	REG32(IPC_ISH2HOST_DOORBELL) = IPC_BUILD_MNG_MSG(0x8, 1);
+
+	interrupt_enable();
+	/* Reschedule the highest priority task. */
+	__schedule(0, 0);
+}
+
+void task_enable_irq(int irq)
+{
+	unmask_interrupt(irq);
+}
+
+void __keep task_disable_irq(int irq)
+{
+	mask_interrupt(irq);
+}
+
+void task_clear_pending_irq(int irq)
+{
+}
+
+void task_trigger_irq(int irq)
+{
+	/* Writing to Local APIC Interrupt Command Register (ICR) causes an
+	 * IPI (Inter-processor interrupt) on the APIC bus. Here we direct the
+	 * IPI to originating prccessor to generate self-interrupt
+	 */
+	REG32(LAPIC_ICR_REG) = LAPIC_ICR_BITS | IRQ_TO_VEC(irq);
+}
+
+void mutex_lock(struct mutex *mtx)
+{
+	uint32_t old_val = 0, value = 1;
+	uint32_t id = 1 << task_get_current();
+
+	ASSERT(id != TASK_ID_INVALID);
+	atomic_or(&mtx->waiters, id);
+
+	do {
+		__asm__ __volatile__(
+				"lock; cmpxchg %1, %2\n"
+				: "=a" (old_val)
+				: "r" (value), "m" (mtx->lock), "a" (old_val)
+				: "memory");
+
+		if (old_val != 0) {
+			/* Contention on the mutex */
+			task_wait_event_mask(TASK_EVENT_MUTEX, 0);
+		}
+	} while (old_val);
+
+	atomic_clear(&mtx->waiters, id);
+}
+
+void mutex_unlock(struct mutex *mtx)
+{
+	uint32_t waiters = 0;
+	uint32_t old_val = 1, val = 0;
+	task_ *tsk = current_task;
+
+	__asm__ __volatile__(
+			"lock; cmpxchg %1, %2\n"
+			: "=a" (old_val)
+			: "r" (val), "m" (mtx->lock), "a" (old_val)
+			: "memory");
+	if (old_val == 1)
+		waiters = mtx->waiters;
+	/* else? Does unlock fail - what to do then ? */
+	while (waiters) {
+		task_id_t id = __fls(waiters);
+
+		waiters &= ~(1 << id);
+
+		/* Somebody is waiting on the mutex */
+		task_set_event(id, TASK_EVENT_MUTEX, 0);
+	}
+
+	/* Ensure no event is remaining from mutex wake-up */
+	atomic_clear(&tsk->events, TASK_EVENT_MUTEX);
+}
+
+void task_print_list(void)
+{
+	int i;
+
+	ccputs("Task Ready Name         Events      Time (s)  StkUsed\n");
+
+	for (i = 0; i < TASK_ID_COUNT; i++) {
+		char is_ready = (tasks_ready & (1<<i)) ? 'R' : ' ';
+		uint32_t *sp;
+
+		int stackused = tasks_init[i].stack_size;
+
+		for (sp = tasks[i].stack;
+		     sp < (uint32_t *)tasks[i].sp && *sp == STACK_UNUSED_VALUE;
+		     sp++)
+			stackused -= sizeof(uint32_t);
+
+		ccprintf("%4d %c %-16s %08x %11.6ld  %3d/%3d\n", i, is_ready,
+			 task_names[i], tasks[i].events, tasks[i].runtime,
+			 stackused, tasks_init[i].stack_size);
+		cflush();
+	}
+}
+
+int command_task_info(int argc, char **argv)
+{
+#ifdef CONFIG_TASK_PROFILING
+	int total = 0;
+	int i;
+#endif
+
+	task_print_list();
+
+#ifdef CONFIG_TASK_PROFILING
+	ccputs("IRQ counts by type:\n");
+	cflush();
+	for (i = 0; i < ARRAY_SIZE(irq_dist); i++) {
+		if (irq_dist[i]) {
+			ccprintf("%4d %8d\n", i, irq_dist[i]);
+			total += irq_dist[i];
+		}
+	}
+	ccprintf("Service calls:          %11d\n", svc_calls);
+	ccprintf("Total exceptions:       %11d\n", total + svc_calls);
+	ccprintf("Task switches:          %11d\n", task_switches);
+	ccprintf("Task switching started: %11.6ld s\n", task_start_time);
+	ccprintf("Time in tasks:          %11.6ld s\n",
+		 get_time().val - task_start_time);
+	ccprintf("Time in exceptions:     %11.6ld s\n", exc_total_time);
+#endif
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(taskinfo, command_task_info,
+			NULL,
+			"Print task info",
+			NULL);
+
+#ifdef CONFIG_CMD_TASKREADY
+static int command_task_ready(int argc, char **argv)
+{
+	if (argc < 2) {
+		ccprintf("tasks_ready: 0x%08x\n", tasks_ready);
+	} else {
+		tasks_ready = strtoi(argv[1], NULL, 16);
+		ccprintf("Setting tasks_ready to 0x%08x\n", tasks_ready);
+		__schedule(0, 0);
+	}
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(taskready, command_task_ready,
+			"[setmask]",
+			"Print/set ready tasks",
+			NULL);
+#endif
+
+void task_pre_init(void)
+{
+	int i, cs;
+	uint32_t *stack_next = (uint32_t *)task_stacks;
+
+	uint8_t default_fp_ctx[] = { /*Initial FP state */
+		0x7f, 0x03, 0xff, 0xff, 0x00, 0x00,
+		0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+
+	__asm__ __volatile__ ("movl %%cs, %0":"=r" (cs));
+
+	/* Fill the task memory with initial values */
+	for (i = 0; i < TASK_ID_COUNT; i++) {
+		uint32_t *sp;
+		/* Stack size in words */
+		uint32_t ssize = tasks_init[i].stack_size / 4;
+
+		tasks[i].stack = stack_next;
+
+		/*
+		 * Update stack used by first frame: 8 words for the register
+		 * stack, plus 8 for task context.
+		 */
+		sp = stack_next + ssize - 16;
+		tasks[i].sp = (uint32_t)sp;
+
+		/* Initial context on stack (see __switchto()) */
+
+		/* For POPA */
+#if 0
+		/* For debug */
+		sp[0] = 0xee;	/* EDI */
+		sp[1] = 0xe5;	/* ESI */
+		sp[2] = 0x00;	/* EBP */
+		sp[3] = 0x00;	/* ESP - ignored anyway */
+		sp[4] = 0xeb1;	/* EBX */
+		sp[5] = 0xed1;	/* EDX */
+		sp[6] = 0xec;	/* ECX */
+		sp[7] = 0xea;	/* EAX */
+#endif
+		/* For IRET */
+		sp[8] = tasks_init[i].pc;	/* pc */
+		sp[9] = cs;
+		sp[10] = INITIAL_EFLAGS;
+
+		sp[11] = (uint32_t) task_exit_trap;
+		sp[12] = 0x00;
+		sp[13] = 0x00;
+		sp[14] = 0x00;
+		sp[15] = 0x00;
+
+#ifdef CONFIG_FPU
+		/* Copy default x86 FPU state for each task */
+		memcpy(tasks[i].fp_ctx, default_fp_ctx,
+			sizeof(default_fp_ctx));
+#endif
+		/* Fill unused stack; also used to detect stack overflow. */
+		for (sp = stack_next; sp < (uint32_t *)tasks[i].sp; sp++)
+			*sp = STACK_UNUSED_VALUE;
+
+		stack_next += ssize;
+	}
+
+	current_task = __task_id_to_ptr(1);
+
+	/* Initialize IRQs */
+	init_interrupts();
+
+}
+
+void task_clear_fp_used(void)
+{
+}
+
+int task_start(void)
+{
+#ifdef CONFIG_TASK_PROFILING
+	task_start_time = exc_end_time = get_time().val;
+#endif
+	return __task_start(&need_resched_or_profiling);
+}
--- a/core/minute-ia/task_defs.h
+++ b/core/minute-ia/task_defs.h
@@ -0,0 +1,47 @@
+/* Copyright (c) 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_TASK_DEFS_H
+#define __CROS_EC_TASK_DEFS_H
+
+#define FPU_CTX_SZ		108 /* 28 bytes header + 80 bytes registers */
+#define FPU_CTX_OFFSET		20  /* offsetof(task_, fp_ctx) */
+
+#ifndef __ASSEMBLER__
+typedef union {
+	struct {
+		/*
+		 * Note that sp must be the first element in the task struct
+		 * for __switchto() to work.
+		 */
+		uint32_t sp;	/* Saved stack pointer for context switch */
+		uint32_t events;	/* Bitmaps of received events */
+		uint64_t runtime;	/* Time spent in task */
+		uint32_t *stack;	/* Start of stack */
+#ifdef CONFIG_FPU
+		uint8_t fp_ctx[FPU_CTX_SZ]; /* x87 FPU context */
+#endif
+	};
+} task_;
+
+int __task_start(int *task_stack_ready);
+void __switchto(void);
+
+/* Only the IF bit is set so tasks start with interrupts enabled. */
+#define INITIAL_EFLAGS		(0x200UL)
+
+/* LAPIC ICR bit fields
+ *	7:0	- vector
+ *	10:8	- Delivery mode (0 = fixed)
+ *	11	- Destination mode (0 = physical)
+ *	12	- Delivery status (0 = Idle)
+ *	14	- Level (1 = assert)
+ *	15	- Trigger mode (0 = edge)
+ *	20:18	- Destination (1 = self)
+ */
+#define LAPIC_ICR_BITS		0x44000
+
+#endif /* __ASSEMBLER__ */
+#endif /* __CROS_EC_TASK_DEFS_H */