arch: native: Run Zephyr natively in a POSIX OS

A new arch (posix) which relies on pthreads to emulate the context
switching
A new soc for it (inf_clock) which emulates a CPU running at an
infinely high clock (so when the CPU is awaken it runs till completion
in 0 time)
A new board, which provides a trivial system tick timer and
irq generation.

Origin: Original

Fixes #1891

Signed-off-by: Alberto Escolar Piedras <[email protected]>
Signed-off-by: Anas Nashif <[email protected]>

Author: aescolar

CMakeLists.txt

@@ -64,7 +64,6 @@ zephyr_include_directories(
   ${STDINCLUDE}
 )
 
-
 zephyr_compile_definitions(
   KERNEL
   __ZEPHYR__=1
@@ -95,11 +94,13 @@ zephyr_compile_options(
   -Wformat
   -Wformat-security
   -Wno-format-zero-length
-  -Wno-main
+  -imacros ${AUTOCONF_H}
   -ffreestanding
-  -include ${AUTOCONF_H}
+  -Wno-main
+  ${NOSTDINC_F}
 )
 
+
 zephyr_compile_options(
   $<$<COMPILE_LANGUAGE:C>:-std=c99>
 
@@ -114,13 +115,15 @@ zephyr_compile_options(
   $<$<COMPILE_LANGUAGE:ASM>:-D_ASMLANGUAGE>
 )
 
+if(NOT CONFIG_NATIVE_APPLICATION)
 zephyr_ld_options(
   -nostartfiles
   -nodefaultlibs
   -nostdlib
   -static
   -no-pie
-  )
+)
+endif()
 
 # ==========================================================================
 #
@@ -231,7 +234,6 @@ endif()
 zephyr_cc_option_ifdef(CONFIG_DEBUG_SECTION_MISMATCH -fno-inline-functions-called-once)
 zephyr_cc_option_ifdef(CONFIG_STACK_USAGE            -fstack-usage)
 
-zephyr_compile_options(-nostdinc)
 zephyr_system_include_directories(${NOSTDINC})
 
 # Force an error when things like SYS_INIT(foo, ...) occur with a missing header.
@@ -248,9 +250,15 @@ if(IS_TEST)
 endif()
 
 set_ifndef(LINKERFLAGPREFIX -Wl)
+
+if(NOT CONFIG_NATIVE_APPLICATION)
 zephyr_ld_options(
   ${LINKERFLAGPREFIX},-X
   ${LINKERFLAGPREFIX},-N
+  )
+endif()
+
+zephyr_ld_options(
   ${LINKERFLAGPREFIX},--gc-sections
   ${LINKERFLAGPREFIX},--build-id=none
   )
@@ -502,7 +510,7 @@ add_custom_command(
   # TODO: Remove duplication
   COMMAND ${CMAKE_C_COMPILER}
   -x assembler-with-cpp
-  -nostdinc
+  ${NOSTDINC_F}
   -undef
   -MD -MF linker.cmd.dep -MT ${BASE_NAME}/linker.cmd
   ${ZEPHYR_INCLUDES}
@@ -676,12 +684,20 @@ endif()
 get_property(GKOF GLOBAL PROPERTY GENERATED_KERNEL_OBJECT_FILES)
 get_property(GKSF GLOBAL PROPERTY GENERATED_KERNEL_SOURCE_FILES)
 
+get_property(TOPT GLOBAL PROPERTY TOPT)
+set_ifndef(  TOPT -T)
+
 # FIXME: Is there any way to get rid of empty_file.c?
 add_executable(       zephyr_prebuilt misc/empty_file.c)
-target_link_libraries(zephyr_prebuilt -T${PROJECT_BINARY_DIR}/linker.cmd ${zephyr_lnk})
+target_link_libraries(zephyr_prebuilt ${TOPT} ${PROJECT_BINARY_DIR}/linker.cmd ${zephyr_lnk})
 set_property(TARGET   zephyr_prebuilt PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker.cmd)
 add_dependencies(     zephyr_prebuilt linker_script offsets)
 
+
+if(NOT CONFIG_NATIVE_APPLICATION)
+	set(NOSTDINC_F -nostdinc)
+endif()
+
 if(GKOF OR GKSF)
   set(logical_target_for_zephyr_elf kernel_elf)
 
@@ -694,7 +710,7 @@ if(GKOF OR GKSF)
     ${LINKER_SCRIPT_DEP}
     COMMAND ${CMAKE_C_COMPILER}
     -x assembler-with-cpp
-    -nostdinc
+    ${NOSTDINC_F}
     -undef
     -MD -MF linker_pass2.cmd.dep -MT ${BASE_NAME}/linker_pass2.cmd
     ${ZEPHYR_INCLUDES}
@@ -713,7 +729,7 @@ if(GKOF OR GKSF)
     )
 
   add_executable(       kernel_elf misc/empty_file.c ${GKSF})
-  target_link_libraries(kernel_elf ${GKOF} -T${PROJECT_BINARY_DIR}/linker_pass2.cmd ${zephyr_lnk})
+  target_link_libraries(kernel_elf ${GKOF} ${TOPT} ${PROJECT_BINARY_DIR}/linker_pass2.cmd ${zephyr_lnk})
   set_property(TARGET   kernel_elf PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker_pass2.cmd)
   add_dependencies(     kernel_elf linker_pass2_script)
 else()

arch/Kconfig

@@ -34,6 +34,14 @@ config RISCV32
 config XTENSA
 	bool "Xtensa architecture"
 
+config ARCH_POSIX
+	bool "POSIX (native) architecture"
+	select ATOMIC_OPERATIONS_BUILTIN
+	select ARCH_HAS_CUSTOM_SWAP_TO_MAIN
+	select ARCH_HAS_CUSTOM_BUSY_WAIT
+	select ARCH_HAS_THREAD_ABORT
+	select NATIVE_APPLICATION
+
 endchoice
 
 

arch/posix/CMakeLists.txt

@@ -0,0 +1,37 @@
+zephyr_cc_option_ifdef(CONFIG_LTO -flto)
+
+zephyr_compile_options(
+  -fno-freestanding
+  -Wno-undef
+  -Wno-implicit-function-declaration
+  -m32
+  -MMD
+  -MP
+  ${TOOLCHAIN_C_FLAGS}
+  ${ARCH_FLAG}
+  -include ${PROJECT_SOURCE_DIR}/arch/posix/include/posix_cheats.h
+  )
+
+zephyr_compile_definitions(_POSIX_C_SOURCE=199309)
+
+zephyr_ld_options(
+  -ldl
+  -pthread
+  -m32
+)
+
+# About the -include directive: The reason to do it this way, is because in this
+# manner it is transparent to the application. Otherwise posix_cheats.h needs to
+# be included in all the applications' files which define main( ), and in any
+# app file which uses the pthreads like API provided by Zephyr
+# ( include/posix/pthread.h / kernel/pthread.c ) [And any future API added to
+# Zephyr which will clash with the native POSIX API] . It would also need to
+# be included in a few zephyr kernel files.
+
+
+add_subdirectory(soc)
+add_subdirectory(core)
+
+# Override the flag used with linker.cmd
+# "-Wl,--just-symbols linker.cmd" instead of "-T linker.cmd"
+set_property(GLOBAL PROPERTY TOPT -Wl,--just-symbols)

arch/posix/Kconfig

@@ -0,0 +1,31 @@
+# Kconfig - General configuration options
+
+#
+# Copyright (c) 2017 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+choice
+	prompt "POSIX Configuration Selection"
+	depends on ARCH_POSIX
+
+	source "arch/posix/soc/*/Kconfig.soc"
+endchoice
+
+menu "POSIX (native) Options"
+	depends on ARCH_POSIX
+
+config ARCH
+	default "posix"
+
+config ARCH_DEFCONFIG
+	string
+	default "arch/posix/defconfig"
+
+source "arch/posix/core/Kconfig"
+
+
+source "arch/posix/soc/*/Kconfig"
+
+endmenu

arch/posix/core/CMakeLists.txt

@@ -0,0 +1,9 @@
+zephyr_library()
+zephyr_library_compile_definitions(_POSIX_CHEATS_H)
+zephyr_library_sources(
+	cpuhalt.c
+	fatal.c
+	posix_core.c
+	swap.c
+	thread.c
+	)

arch/posix/core/cpuhalt.c

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2011-2015 Wind River Systems, Inc.
+ * Copyright (c) 2017 Oticon A/S
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+/**
+ * @file  CPU power management code for POSIX
+ *
+ * This module provides an implementation of the architecture-specific
+ * k_cpu_idle() primitive required by the kernel idle loop component.
+ * It can be called within an implementation of _sys_power_save_idle(),
+ * which is provided for the kernel by the platform.
+ *
+ * The module also provides an implementation of k_cpu_atomic_idle(), which
+ * atomically re-enables interrupts and enters low power mode.
+ *
+ */
+
+#include "posix_core.h"
+#include "posix_soc_if.h"
+
+/**
+ *
+ * @brief Power save idle routine for IA-32
+ *
+ * This function will be called by the kernel idle loop or possibly within
+ * an implementation of _sys_power_save_idle in the kernel when the
+ * '_sys_power_save_flag' variable is non-zero.
+ *
+ * This function is just a pass thru to the SOC one
+ *
+ * @return N/A
+ */
+void k_cpu_idle(void)
+{
+	posix_irq_full_unlock();
+	posix_halt_cpu();
+}
+
+/**
+ *
+ * @brief Atomically re-enable interrupts and enter low power mode
+ *
+ * INTERNAL
+ * The requirements for k_cpu_atomic_idle() are as follows:
+ * 1) The enablement of interrupts and entering a low-power mode needs to be
+ *    atomic, i.e. there should be no period of time where interrupts are
+ *    enabled before the processor enters a low-power mode.  See the comments
+ *    in k_lifo_get(), for example, of the race condition that
+ *    occurs if this requirement is not met.
+ *
+ * 2) After waking up from the low-power mode, the interrupt lockout state
+ *    must be restored as indicated in the 'imask' input parameter.
+ *
+ * This function is just a pass thru to the SOC one
+ *
+ * @return N/A
+ */
+
+void k_cpu_atomic_idle(unsigned int imask)
+{
+	posix_atomic_halt_cpu(imask);
+}

arch/posix/core/fatal.c

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2017 Oticon A/S
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <kernel.h>
+#include <arch/cpu.h>
+#include <kernel_structs.h>
+#include <misc/printk.h>
+#include <inttypes.h>
+#include "posix_soc_if.h"
+
+const NANO_ESF _default_esf = {
+	0xdeadbaad
+};
+
+/**
+ *
+ * @brief Kernel fatal error handler
+ *
+ * This routine is called when a fatal error condition is detected
+ *
+ * The caller is expected to always provide a usable ESF.  In the event that the
+ * fatal error does not have a hardware generated ESF, the caller should either
+ * create its own or call _Fault instead.
+ *
+ * @param reason the reason that the handler was called
+ * @param pEsf pointer to the exception stack frame
+ *
+ * @return This function does not return.
+ */
+FUNC_NORETURN void _NanoFatalErrorHandler(unsigned int reason,
+		const NANO_ESF *esf)
+{
+#ifdef CONFIG_PRINTK
+	switch (reason) {
+	case _NANO_ERR_CPU_EXCEPTION:
+	case _NANO_ERR_SPURIOUS_INT:
+		break;
+
+	case _NANO_ERR_INVALID_TASK_EXIT:
+		printk("***** Invalid Exit Software Error! *****\n");
+		break;
+
+
+	case _NANO_ERR_ALLOCATION_FAIL:
+		printk("**** Kernel Allocation Failure! ****\n");
+		break;
+
+	case _NANO_ERR_KERNEL_OOPS:
+		printk("***** Kernel OOPS! *****\n");
+		break;
+
+	case _NANO_ERR_KERNEL_PANIC:
+		printk("***** Kernel Panic! *****\n");
+		break;
+
+#ifdef CONFIG_STACK_SENTINEL
+	case _NANO_ERR_STACK_CHK_FAIL:
+		printk("***** Stack overflow *****\n");
+		break;
+#endif
+	default:
+		printk("**** Unknown Fatal Error %u! ****\n", reason);
+		break;
+	}
+
+#endif
+
+	void _SysFatalErrorHandler(unsigned int reason,
+			const NANO_ESF *pEsf);
+	_SysFatalErrorHandler(reason, esf);
+}
+
+
+/**
+ *
+ * @brief Fatal error handler
+ *
+ * This routine implements the corrective action to be taken when the system
+ * detects a fatal error.
+ *
+ * This sample implementation attempts to abort the current thread and allow
+ * the system to continue executing, which may permit the system to continue
+ * functioning with degraded capabilities.
+ *
+ * System designers may wish to enhance or substitute this sample
+ * implementation to take other actions, such as logging error (or debug)
+ * information to a persistent repository and/or rebooting the system.
+ *
+ * @param reason the fatal error reason
+ * @param pEsf pointer to exception stack frame
+ *
+ * @return N/A
+ */
+FUNC_NORETURN __weak void _SysFatalErrorHandler(unsigned int reason,
+		const NANO_ESF *pEsf)
+{
+	ARG_UNUSED(pEsf);
+
+#ifdef CONFIG_STACK_SENTINEL
+	if (reason == _NANO_ERR_STACK_CHK_FAIL) {
+		goto hang_system;
+	}
+#endif
+	if (reason == _NANO_ERR_KERNEL_PANIC) {
+		goto hang_system;
+	}
+	if (k_is_in_isr() || _is_thread_essential()) {
+		posix_print_error_and_exit(
+			"Fatal fault in %s! Stopping...\n",
+			k_is_in_isr() ? "ISR" : "essential thread");
+	}
+	printk("Fatal fault in thread %p! Aborting.\n", _current);
+	k_thread_abort(_current);
+
+hang_system:
+
+	posix_print_error_and_exit(
+		"Stopped in _SysFatalErrorHandler()\n");
+	CODE_UNREACHABLE;
+}