updates write for coremark

CMakeLists.txt

@@ -1,11 +0,0 @@
-if (NOT DEFINED BOARD)
-	set(BOARD iss)
-endif()
-if (NOT DEFINED ISA)
-	set(ISA imc)
-endif()
-message(STATUS "Building firmware using ${BOARD} board configuration and isa ${ISA}")
-add_custom_target(fw-common ALL 
-	COMMAND make -C hello-world BOARD=${BOARD} ISA=${ISA} && make -C benchmarks/dhrystone BOARD=${BOARD} ISA=${ISA} && make -C benchmarks/coremark BOARD=${BOARD} ISA=${ISA}
-    USES_TERMINAL
-    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})

bare-metal-bsp

@@ -1 +1 @@
-Subproject commit 87dc0ec2304adcb94a25b397a357aadae1304867
+Subproject commit 540397494a48b07b1e8282b6059689246b622564

benchmarks/coremark/CMakeLists.txt

@@ -0,0 +1,46 @@
+cmake_minimum_required(VERSION 3.21)
+project(coremark C)
+set(TARGET coremark)
+#set(CMAKE_BUILD_TYPE Release)
+
+option(HAVE_NO_INIT_FINI "Enable NO_INIT_FINI" OFF)
+
+if(HAVE_NO_INIT_FINI)
+  #if HAVE_NO_INIT_FINI is ON
+  add_definitions(-DHAVE_NO_INIT_FINI)
+endif()
+
+
+# Source files
+set(SOURCES
+    core_portme.c
+    cvt.c
+    ee_printf.c
+    cm/core_list_join.c
+    cm/core_main.c
+    cm/core_matrix.c
+    cm/core_state.c
+    cm/core_util.c
+)
+
+
+# Create executable
+add_executable(coremark ${SOURCES})
+target_include_directories(${TARGET} PRIVATE ${CMAKE_CURRENT_LIST_DIR} ${CMAKE_CURRENT_LIST_DIR}/cm)
+target_compile_options(${TARGET} PRIVATE  -Wno-pointer-to-int-cast -Wno-int-to-pointer-cast -fno-builtin-strnlen -fno-common -funroll-loops -finline-functions -falign-functions=16 -falign-jumps=4 -falign-loops=4 -finline-limit=1000 -fno-if-conversion2 -fselective-scheduling -fno-crossjumping -freorder-blocks-and-partition -Wno-pointer-to-int-cast -Wno-int-to-pointer-cast -fno-common -funroll-loops -finline-functions -falign-functions=16 -falign-jumps=4 -falign-loops=4 -finline-limit=1000 -fno-if-conversion2 -fselective-scheduling -fno-crossjumping -freorder-blocks-and-partition )
+target_compile_definitions(${TARGET} PRIVATE PERFORMANCE_RUN=1 CLOCKS_PER_SEC=10000000 FLAGS_STR="" PERFORMANCE_RUN=1 CLOCKS_PER_SEC=10000000 ITERATIONS=600)
+
+set(BOARD "iss" CACHE STRING "Target board")
+add_subdirectory(../../bare-metal-bsp bsp)
+target_link_libraries(${TARGET} PRIVATE bsp)
+target_link_options(${TARGET} PRIVATE -Wl,-Map=${TARGET}.map)  
+
+include(CMakePrintHelpers)
+cmake_print_properties(TARGETS ${TARGET} PROPERTIES COMPILE_DEFINITIONS COMPILE_OPTIONS LINK_OPTIONS INTERFACE_LINK_OPTIONS)
+
+#message(STATUS "CMAKE_BUILD_TYPE = ${CMAKE_BUILD_TYPE}")
+#message(STATUS "CMAKE_C_FLAGS = ${CMAKE_C_FLAGS}")
+
+add_custom_command(TARGET ${TARGET} POST_BUILD
+        COMMAND ${CMAKE_OBJDUMP} -S  ${TARGET}.elf > ${TARGET}.dis
+        COMMENT "Creating disassembly for ${TARGET}")

benchmarks/coremark/CMakePresets.json

@@ -0,0 +1,70 @@
+{
+    "version": 3,
+    "vendor": {
+        "conan": {}
+    },
+    "cmakeMinimumRequired": {
+        "major": 3,
+        "minor": 24,
+        "patch": 0
+    },
+    "configurePresets": [
+        {
+            "name": "debug",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",       
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_moon",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "moonlight",
+                "HAVE_NO_INIT_FINI": "ON",   
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_tgc",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "tgc_vp",   
+                "HAVE_NO_INIT_FINI": "ON",
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_64",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",       
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "debug_64_moon",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "moonlight",
+                "HAVE_NO_INIT_FINI": "ON",   
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "debug_64_tgc",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "tgc_vp",   
+                "HAVE_NO_INIT_FINI": "ON",
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "release",
+            "cacheVariables": {
+                "CMAKE_BUILD_TYPE": "Release",    
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        }
+    ]
+}

benchmarks/coremark/core_portme.c

@@ -15,55 +15,58 @@ limitations under the License.
 
 Original Author: Shay Gal-on
 */
-#include "coremark.h"
 #include "core_portme.h"
-//Read cycle CSR
+#include "coremark.h"
-unsigned long long _read_cycle()
+#include <unistd.h>
-{
+// Read cycle CSR
-    unsigned long long result;
+unsigned long long _read_cycle() {
-    unsigned long lower;
+  unsigned long long result;
-    unsigned long upper1;
+  unsigned long lower;
-    unsigned long upper2;
+  unsigned long upper1;
+  unsigned long upper2;
 
-    asm volatile (
+  asm volatile("repeat_cycle_%=: csrr %0, cycleh;\n"
-        "repeat_cycle_%=: csrr %0, cycleh;\n"
+               "        csrr %1, cycle;\n"
-        "        csrr %1, cycle;\n"
+               "        csrr %2, cycleh;\n"
-        "        csrr %2, cycleh;\n"
+               "        bne %0, %2, repeat_cycle_%=;\n"
-        "        bne %0, %2, repeat_cycle_%=;\n"
+               : "=r"(upper1), "=r"(lower),
-        : "=r" (upper1),"=r" (lower),"=r" (upper2)    // Outputs   : temp variable for load result
+                 "=r"(upper2) // Outputs   : temp variable for load result
-        :
+               :
-        :
+               :);
-    );
+  *(unsigned long *)(&result) = lower;
-    *(unsigned long *)(&result) = lower;
+  *((unsigned long *)(&result) + 1) = upper1;
-    *((unsigned long *)(&result)+1) = upper1;
 
-    return result;
+  return result;
 }
 
-volatile int tohost;
+// extern volatile int tohost;
-volatile int fromhost;
+// extern volatile int fromhost;
 
-void exit(int n){
+void write_hex(int fd, uint32_t hex);
-      tohost = 0x1;
+
-      for (;;);
+void exit(int n) {
+  write_hex(STDERR_FILENO, 1);
+  // tohost = 0x1;
+  for (;;)
+    ;
 }
 
-void __libc_init_array (void) {
+void __libc_init_array(void) {
-/*
+  /*
-    size_t count;
+      size_t count;
-    size_t i;
+      size_t i;
-    count = __preinit_array_end - __preinit_array_start;
+      count = __preinit_array_end - __preinit_array_start;
-    for (i = 0; i < count; i++)
+      for (i = 0; i < count; i++)
-        __preinit_array_start[i] ();
+          __preinit_array_start[i] ();
 
-#ifdef HAVE_INIT_FINI
+  #ifdef HAVE_INIT_FINI
-    _init ();
+      _init ();
-#endif
+  #endif
 
-    count = __init_array_end - __init_array_start;
+      count = __init_array_end - __init_array_start;
-    for (i = 0; i < count; i++)
+      for (i = 0; i < count; i++)
-    __init_array_start[i] ();
+      __init_array_start[i] ();
-*/
+  */
 }
 #if VALIDATION_RUN
 volatile ee_s32 seed1_volatile = 0x3415;
@@ -89,10 +92,7 @@ volatile ee_s32 seed5_volatile = 0;
    time.h and windows.h definitions included.
 */
 CORETIMETYPE
-barebones_clock()
+barebones_clock() { return (CORETIMETYPE)_read_cycle(); }
-{
-    return (CORETIMETYPE)_read_cycle();
-}
 /* Define : TIMER_RES_DIVIDER
         Divider to trade off timer resolution and total time that can be
    measured.
@@ -101,11 +101,11 @@ barebones_clock()
    does not occur. If there are issues with the return value overflowing,
    increase this value.
         */
-#define GETMYTIME(_t)              (*_t = barebones_clock())
+#define GETMYTIME(_t) (*_t = barebones_clock())
-#define MYTIMEDIFF(fin, ini)       ((fin) - (ini))
+#define MYTIMEDIFF(fin, ini) ((fin) - (ini))
-#define TIMER_RES_DIVIDER          1
+#define TIMER_RES_DIVIDER 1
 #define SAMPLE_TIME_IMPLEMENTATION 1
-#define EE_TICKS_PER_SEC           (CLOCKS_PER_SEC / TIMER_RES_DIVIDER)
+#define EE_TICKS_PER_SEC (CLOCKS_PER_SEC / TIMER_RES_DIVIDER)
 
 /** Define Host specific (POSIX), or target specific global time variables. */
 static CORETIMETYPE start_time_val, stop_time_val;
@@ -118,11 +118,7 @@ static CORETIMETYPE start_time_val, stop_time_val;
    example code) or zeroing some system parameters - e.g. setting the cpu clocks
    cycles to 0.
 */
-void
+void start_time(void) { GETMYTIME(&start_time_val); }
-start_time(void)
-{
-    GETMYTIME(&start_time_val);
-}
 /* Function : stop_time
         This function will be called right after ending the timed portion of the
    benchmark.
@@ -131,11 +127,7 @@ start_time(void)
    example code) or other system parameters - e.g. reading the current value of
    cpu cycles counter.
 */
-void
+void stop_time(void) { GETMYTIME(&stop_time_val); }
-stop_time(void)
-{
-    GETMYTIME(&stop_time_val);
-}
 /* Function : get_time
         Return an abstract "ticks" number that signifies time on the system.
 
@@ -146,11 +138,9 @@ stop_time(void)
    controlled by <TIMER_RES_DIVIDER>
 */
 CORE_TICKS
-get_time(void)
+get_time(void) {
-{
+  CORE_TICKS elapsed = (CORE_TICKS)(MYTIMEDIFF(stop_time_val, start_time_val));
-    CORE_TICKS elapsed
+  return elapsed;
-        = (CORE_TICKS)(MYTIMEDIFF(stop_time_val, start_time_val));
-    return elapsed;
 }
 /* Function : time_in_secs
         Convert the value returned by get_time to seconds.
@@ -159,11 +149,9 @@ get_time(void)
    floating point. Default implementation implemented by the EE_TICKS_PER_SEC
    macro above.
 */
-secs_ret
+secs_ret time_in_secs(CORE_TICKS ticks) {
-time_in_secs(CORE_TICKS ticks)
+  secs_ret retval = ((secs_ret)ticks) / (secs_ret)EE_TICKS_PER_SEC;
-{
+  return retval;
-    secs_ret retval = ((secs_ret)ticks) / (secs_ret)EE_TICKS_PER_SEC;
-    return retval;
 }
 
 ee_u32 default_num_contexts = 1;
@@ -172,27 +160,18 @@ ee_u32 default_num_contexts = 1;
         Target specific initialization code
         Test for some common mistakes.
 */
-void
+void portable_init(core_portable *p, int *argc, char *argv[]) {
-portable_init(core_portable *p, int *argc, char *argv[])
+  if (sizeof(ee_ptr_int) != sizeof(ee_u8 *)) {
-{
+    ee_printf("ERROR! Please define ee_ptr_int to a type that holds a "
-    if (sizeof(ee_ptr_int) != sizeof(ee_u8 *))
+              "pointer!\n");
-    {
+  }
-        ee_printf(
+  if (sizeof(ee_u32) != 4) {
-            "ERROR! Please define ee_ptr_int to a type that holds a "
+    ee_printf("ERROR! Please define ee_u32 to a 32b unsigned type!\n");
-            "pointer!\n");
+  }
-    }
+  p->portable_id = 1;
-    if (sizeof(ee_u32) != 4)
+  ee_printf("portable_init finished.\n");
-    {
-        ee_printf("ERROR! Please define ee_u32 to a 32b unsigned type!\n");
-    }
-    p->portable_id = 1;
-    ee_printf("portable_init finished.\n");
 }
 /* Function : portable_fini
         Target specific final code
 */
-void
+void portable_fini(core_portable *p) { p->portable_id = 0; }
-portable_fini(core_portable *p)
-{
-    p->portable_id = 0;
-}

benchmarks/dhrystone/.gitignore

@@ -1,2 +1,3 @@
 dhrystone
 /dhrystone.dis
+build/

benchmarks/dhrystone/CMakeLists.txt

@@ -0,0 +1,31 @@
+cmake_minimum_required(VERSION 3.21)
+project(dhrystone C)
+set(TARGET dhrystone)
+
+option(HAVE_NO_INIT_FINI "Enable NO_INIT_FINI" OFF)
+
+if(HAVE_NO_INIT_FINI)
+  #if HAVE_NO_INIT_FINI is ON
+  add_definitions(-DHAVE_NO_INIT_FINI)
+endif()
+
+set(ITERATIONS 50000) # 20000 for TGC
+
+add_executable(${TARGET} dhry_1.c dhry_2.c dhry_stubs.c)
+target_include_directories(${TARGET} PRIVATE ${CMAKE_CURRENT_LIST_DIR})
+target_compile_options(${TARGET} PRIVATE -fno-inline -fno-builtin-printf -fno-common -Wno-implicit -funroll-loops -fpeel-loops -fgcse-sm -fgcse-las)
+target_compile_definitions(${TARGET} PRIVATE ITERATIONS=${ITERATIONS} HZ=32768 TIME NO_INIT)
+
+set(BOARD "iss" CACHE STRING "Target board")
+add_subdirectory(../../bare-metal-bsp bsp)
+target_link_libraries(${TARGET} PRIVATE bsp)
+target_link_options(${TARGET} PRIVATE LINKER:--wrap=scanf)
+#target_link_options(${TARGET} PRIVATE LINKER:--wrap=scanf -Wl,--no-gc-sections)
+
+target_link_options(${TARGET} PRIVATE -Wl,-Map=${TARGET}.map)  
+include(CMakePrintHelpers)
+cmake_print_properties(TARGETS ${TARGET} PROPERTIES COMPILE_DEFINITIONS COMPILE_OPTIONS LINK_OPTIONS INTERFACE_LINK_OPTIONS)
+
+add_custom_command(TARGET ${TARGET} POST_BUILD
+        COMMAND ${CMAKE_OBJDUMP} -S  ${TARGET}.elf > ${TARGET}.dis
+        COMMENT "Creating disassembly for ${TARGET}")

benchmarks/dhrystone/CMakePresets.json

@@ -0,0 +1,70 @@
+{
+    "version": 3,
+    "vendor": {
+        "conan": {}
+    },
+    "cmakeMinimumRequired": {
+        "major": 3,
+        "minor": 24,
+        "patch": 0
+    },
+    "configurePresets": [
+        {
+            "name": "debug",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",       
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_moon",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "moonlight",
+                "HAVE_NO_INIT_FINI": "ON",   
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_tgc",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "tgc_vp",   
+                "HAVE_NO_INIT_FINI": "ON",
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_64",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",       
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "debug_64_moon",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "moonlight",
+                "HAVE_NO_INIT_FINI": "ON",   
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "debug_64_tgc",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "tgc_vp",   
+                "HAVE_NO_INIT_FINI": "ON",
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "release",
+            "cacheVariables": {
+                "CMAKE_BUILD_TYPE": "Release",    
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        }
+    ]
+}

benchmarks/dhrystone/Makefile

@@ -17,6 +17,7 @@ endif
 # '-lgcc -lm' are needed to add softfloat routines
 CFLAGS  := -g -O3 -DITERATIONS=$(ITERATIONS) -DHZ=32768 -DTIME -DNO_INIT -fno-inline -fno-builtin-printf -fno-common -Wno-implicit \
  -funroll-loops -fpeel-loops -fgcse-sm -fgcse-las
+LDFLAGS := -Wl,--wrap=scanf
 
 TOOL_DIR=$(dir $(compiler))
 

benchmarks/dhrystone/dhry_stubs.c

@@ -1,4 +1,5 @@
 #include "platform.h"
+#include <unistd.h>
 #ifndef ITERATIONS
 #define ITERATIONS 20000
 #endif
@@ -6,20 +7,16 @@
 /* The functions in this file are only meant to support Dhrystone on an
  * embedded RV32 system and are obviously incorrect in general. */
 
-long time(void)
+long time(void) { return get_timer_value(); }
-{
-  return get_timer_value();
-}
 
 // set the number of dhrystone iterations
-void __wrap_scanf(const char* fmt, int* n)
+void __wrap_scanf(const char *fmt, int *n) { *n = ITERATIONS; }
-{
-  *n = ITERATIONS;
-}
 
-extern volatile uint32_t tohost;
+// extern volatile uint64_t tohost;
 
-void exit(int n){
+void exit(int n) {
-      tohost = 0x1;
+  // tohost = 0x1;
-      for (;;);
+  write_hex(STDERR_FILENO, 1);
+  for (;;)
+    ;
 }

hello-world/.gitignore

@@ -1,2 +1,3 @@
 /hello
 /hello.dis
+build/

hello-world/CMakeLists.txt

@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.21)
+project(hello-world C)
+set(TARGET hello)
+option(HAVE_NO_INIT_FINI "Enable NO_INIT_FINI" OFF)
+
+if(HAVE_NO_INIT_FINI)
+  #if HAVE_NO_INIT_FINI is ON
+  add_definitions(-DHAVE_NO_INIT_FINI)
+endif()
+
+add_executable(${TARGET} hello.c)
+
+
+
+set(BOARD "iss" CACHE STRING "Target board")
+message(" BOARD = ${BOARD}")
+add_subdirectory(../bare-metal-bsp bsp)
+target_link_libraries(${TARGET} PRIVATE bsp)
+target_link_options(${TARGET} PRIVATE -Wl,-Map=${TARGET}.map)  
+
+add_custom_command(TARGET ${TARGET} POST_BUILD
+        COMMAND ${CMAKE_OBJDUMP} -S  ${TARGET}.elf > ${TARGET}.dis
+        COMMENT "Creating disassembly for ${TARGET}")

hello-world/CMakePresets.json

@@ -0,0 +1,70 @@
+{
+    "version": 3,
+    "vendor": {
+        "conan": {}
+    },
+    "cmakeMinimumRequired": {
+        "major": 3,
+        "minor": 24,
+        "patch": 0
+    },
+    "configurePresets": [
+        {
+            "name": "debug",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",       
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_moon",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "moonlight",
+                "HAVE_NO_INIT_FINI": "ON",   
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_tgc",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "tgc_vp",   
+                "HAVE_NO_INIT_FINI": "ON",
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        },
+        {
+            "name": "debug_64",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",       
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "debug_64_moon",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "moonlight",
+                "HAVE_NO_INIT_FINI": "ON",   
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "debug_64_tgc",
+            "cacheVariables": {    
+                "CMAKE_BUILD_TYPE": "Debug",  
+                "BOARD": "tgc_vp",   
+                "HAVE_NO_INIT_FINI": "ON",
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv64gc.cmake"
+            }
+        },
+        {
+            "name": "release",
+            "cacheVariables": {
+                "CMAKE_BUILD_TYPE": "Release",    
+                "CMAKE_TOOLCHAIN_FILE": "../../bare-metal-bsp/cmake/rv32imc.cmake"
+            }
+        }
+    ]
+}

hello-world/hello.c

@@ -1,24 +1,37 @@
 #include <stdint.h>
 #include <stdio.h>
+#include <sys/types.h>
 #include <unistd.h>
 
-#include "platform.h"
 #include "encoding.h"
+#include "platform.h"
+#include <string.h>
 
-int factorial(int i){
+int factorial(int i) {
 
-	volatile int result = 1;
+  volatile int result = 1;
-	for (int ii = 1; ii <= i; ii++) {
+  for (int ii = 1; ii <= i; ii++) {
-		result = result * ii;
+    result = result * ii;
-	}
+  }
-	return result;
+  return result;
+}
+extern volatile uintptr_t tohost;
 
+void write_tohost(char *string) {
+  volatile uint64_t payload[4] = {64, 0, (uintptr_t)string,
+                                  (strlen(string) + 1)};
+  tohost = (uintptr_t)payload;
 }
 
-int main()
+int main() {
-{
+  char string[] = "hello world with write in hello";
-	volatile int result = factorial (10);
+
-	printf("Factorial is %d\n", result);
+  write_tohost(string);
-	printf("End of execution");
+
-	return 0;
+  write(STDOUT_FILENO, string, sizeof(string));
+
+  int result = factorial(10);
+  printf("Factorial is %d", result);
+
+  return 0;
 }