Makefile

@@ -3,7 +3,7 @@ CPPFLAGS = -MMD
 AS=nasm
 ASFLAGS += -f elf32
 LDFLAGS += -m elf_i386
-CFLAGS += -m32 -Wall -Wextra -Werror -ffreestanding -fno-exceptions -fno-pie -fno-stack-protector -fno-tree-vectorize -D__KERNEL__
+CFLAGS += -m32 -pipe -Wall -Wextra -Werror -ffreestanding -fno-exceptions -fno-pie -fno-stack-protector -fno-tree-vectorize -D__KERNEL__
 #keep .i and .s
 #CFLAGS += -save-temps
 #CFLAGS += -fanalyzer -Wno-analyzer-malloc-leak -Wno-analyzer-out-of-bounds
@@ -88,11 +88,16 @@ test: clean kernel disk.img
 run:kernel disk.img          ## Run the OS on qemu
 	qemu-system-x86_64 -kernel $< -serial stdio $(QEMU_OPT)
 
-debug: CFLAGS += $(DEBUG_FLAGS) ## Run the OS on qemu and attach a debugger to it (may need a clean befor to have the debug symbols)
+debug: CFLAGS += $(DEBUG_FLAGS) ## Run the OS on qemu and attach a debugger to it (may need a clean before to have the debug symbols)
 debug: CXXFLAGS += $(DEBUG_FLAGS)
 debug:kernel kernel.debug disk.img
 	gdb -q -x debug.gdb
 
+isodebug: CFLAGS += $(DEBUG_FLAGS) ## Same than previous but kernel is loaded by grub. So, for example, we can access the elf debug info
+isodebug: CXXFLAGS += $(DEBUG_FLAGS)
+isodebug:fd.iso disk.img
+	gdb -q -x debug.iso.gdb
+
 debug_test: CFLAGS += $(DEBUG_FLAGS) -DRUN_TEST
 debug_test: debug
 

arch/x86/exception.c

@@ -53,10 +53,12 @@ void print_handler(struct cpu_state *frame, ulong intr)
 
 void pagefault_handler(struct cpu_state *frame, ulong intr)
 {
-
+    // PAGE_FAULT is a interrupt with an error code (see exception_wrapper.S)
+    uint32_t error_code = cpu_context_get_EX_err(frame);
     struct thread *current = getCurrentThread();
-    assert(frame == current->cpuState);
+
     if (cpu_context_is_in_user_mode(current->cpuState)) {
+        assert(frame == current->cpuState); // pagefault in kernel not supported ATM
 
         struct uAddrSpace *as = processGetAddrSpace(current->process);
         vaddr_t faultAddr     = cpu_context_get_EX_faulting_vaddr(frame);
@@ -70,8 +72,6 @@ void pagefault_handler(struct cpu_state *frame, ulong intr)
         if (!uAddrSpaceHeapCheckNAlloc(as, faultAddr))
             goto release_context;
 
-        // PAGE_FAULT is a interrupt with an error code (see exception_wrapper.S)
-        uint32_t error_code = cpu_context_get_EX_err(frame);
         int ret             = uAddrSpaceSolvePageFault(as, faultAddr, error_code & 0x2);
 
         if (!ret)

core/main.c

@@ -46,7 +46,7 @@ void idleThread(void *arg)
 #define FILE_MAX_SIZE   64 // In nb of sectors
 void loadUserSpace()
 {
-    struct ata_partition *part = ATAGetPartition(1);
+    struct ata_partition *part = ATAGetPartitionByType(PART_TYPE_LINUX);
 
     if (part == NULL) {
         printf("No user partition found\n");

core/process.c

@@ -5,12 +5,14 @@
 #include "list.h"
 #include "mmuContext.h"
 #include "types.h"
+#include "thread.h"
 #include "uaddrspace.h"
 
 struct process {
     char name[PROCESS_NAME_MAX_LENGTH];
     int ref;
-    int pid;
+    pid_t pid;
+    pid_t nextTid;
     struct uAddrSpace *addrSpace;
     struct thread *thList;
 
@@ -47,7 +49,8 @@ struct process *processCreate(char *name)
     new->ref = 1;
 
     disable_IRQs(flags);
-    new->pid = nextPid++;
+    new->pid     = nextPid++;
+    new->nextTid = new->pid;
     list_add_tail(processList, new);
     restore_IRQs(flags);
 
@@ -66,7 +69,7 @@ void processListPrint()
         struct thread *th;
         int nbTh;
 
-        printf("%d %s %d %d\n", proc->pid, proc->name, processCountThread(proc), proc->ref);
+        printf("%lu %s %d %d\n", proc->pid, proc->name, processCountThread(proc), proc->ref);
         list_foreach_named(proc->thList, th, nbTh, prevInProcess, nextInProcess)
         {
             if (th == cur) {
@@ -180,3 +183,47 @@ struct uAddrSpace *processGetAddrSpace(struct process *proc){
 int processInitHeap(struct process *proc, uaddr_t lastUserAddr){
     return uAddrSpaceSetHeap(proc->addrSpace, lastUserAddr, 0);
 }
+
+pid_t processGetId(struct process *proc){
+    return proc->pid;
+}
+
+pid_t processGetNextTid(struct process *proc){
+    return proc->nextTid++;
+}
+
+//Should be called with IRQ disabled
+struct thread *processGetThread(struct process *proc, pid_t tid)
+{
+    int count;
+    struct thread *th;
+    struct thread *thFound = NULL;
+
+    list_foreach_named(proc->thList, th, count, prevInProcess, nextInProcess)
+    {
+        if (th->tid == tid) {
+            thFound = th;
+            break;
+        }
+    }
+    return thFound;
+}
+
+int processJoinThread(struct process *proc, pid_t tid)
+{
+    uint32_t flags;
+    struct thread *th;
+    int ret = -1;
+
+    disable_IRQs(flags);
+
+    th = processGetThread(proc, tid);
+    if (th && th->wqExit) {
+        wait(th->wqExit);
+        ret = 0;
+    }
+
+    restore_IRQs(flags);
+
+    return ret;
+}

core/process.h

@@ -1,9 +1,11 @@
 #pragma once
-#include "thread.h"
+#include "types.h"
 
 #define PROCESS_NAME_MAX_LENGTH 32
+typedef unsigned long int pid_t;
 
 struct process;
+struct thread;
 
 int processSetup();
 struct process *processCreate(char *name);
@@ -18,3 +20,6 @@ int processRemoveThread(struct thread *th);
 struct mmu_context *processGetMMUContext(struct process *th);
 struct uAddrSpace *processGetAddrSpace(struct process *proc);
 int processInitHeap(struct process *proc, uaddr_t lastUserAddr);
+pid_t processGetId(struct process *proc);
+pid_t processGetNextTid(struct process *proc);
+int processJoinThread(struct process *proc, pid_t tid);

core/syscall.c

@@ -1,6 +1,8 @@
 #include "syscall.h"
+#include "kernel.h"
 #include "keyboard.h"
 #include "klibc.h"
+#include "paging.h"
 #include "process.h"
 #include "stdarg.h"
 #include "thread.h"
@@ -9,7 +11,6 @@
 #include "uaddrspace.h"
 #include "zero.h"
 
-
 int syscallExecute(int syscallId, const struct cpu_state *userCtx)
 {
 
@@ -43,17 +44,17 @@ int syscallExecute(int syscallId, const struct cpu_state *userCtx)
             printf("Got 5args from userspace %d %d %d %d %d\n", arg1, arg2, arg3, arg4, arg5);
             break;
         }
-        case SYSCALL_ID_BRK:{
+        case SYSCALL_ID_BRK: {
 
             struct uAddrSpace *as;
             uaddr_t newHeapTop;
 
-            as = processGetAddrSpace(getCurrentThread()->process);
+            as  = processGetAddrSpace(getCurrentThread()->process);
             ret = syscallGet1arg(userCtx, (unsigned int *)&newHeapTop);
             if (ret != 0)
                 break;
             threadChangeCurrentContext(uAddrSpaceGetMMUContext(as));
-            //TODO : what if *newHeapTop raise page fault?
+            // TODO : what if *newHeapTop raise page fault?
             ret = sysBrk(as, newHeapTop);
             threadChangeCurrentContext(NULL);
             break;
@@ -110,6 +111,83 @@ int syscallExecute(int syscallId, const struct cpu_state *userCtx)
             ret = uAddrSpaceUnmap(as, uaddr, size);
             break;
         }
+        case SYSCALL_ID_NEW_THREAD: {
+            struct uAddrSpace *as;
+            thread_id_t threadIdPtr;
+            thread_id_t threadId;
+            uaddr_t funcAddr;
+            uint32_t arg1, arg2;
+            size_t stackSize;
+
+            ret = syscallGet5args(userCtx, (unsigned int *)&threadIdPtr,
+                                  (unsigned int *)&funcAddr, (unsigned int *)&arg1,
+                                  (unsigned int *)&arg2, (unsigned int *)&stackSize);
+            if (ret)
+                break;
+            if (stackSize <= 0) {
+                ret = -EINVAL;
+                break;
+            }
+            if (memcpyFromUser((vaddr_t)&threadId, threadIdPtr, sizeof(threadId)) !=
+                sizeof(threadId)) {
+                ret = -EFAULT;
+                break;
+            }
+
+            as        = processGetAddrSpace(getCurrentThread()->process);
+            stackSize = ALIGN(stackSize, PAGE_SIZE);
+
+            uaddr_t stackAddr = 0;
+            ret = zeroMmap(as, &stackAddr, stackSize, PAGING_MEM_READ | PAGING_MEM_WRITE, 0);
+
+            if (ret)
+                break;
+
+            struct thread *th = threadCreateUser(NULL, getCurrentThread()->process, funcAddr,
+                                                 arg1, arg2, stackAddr + stackSize);
+
+            if (th == NULL) {
+                ret = -ENOMEM;
+                uAddrSpaceUnmap(as, stackAddr, stackSize);
+            }
+            threadId = threadGetId(th);
+
+            if (memcpyToUser(threadIdPtr, (vaddr_t)&threadId, sizeof(threadId)) !=
+                sizeof(threadId)) {
+                ret = -EFAULT;
+                break;
+            }
+
+            break;
+        }
+        case SYSCALL_ID_USLEEP: {
+            unsigned int sleep;
+
+            ret = syscallGet1arg(userCtx, &sleep);
+            if (ret)
+                break;
+
+            ret = threadUsleep(sleep);
+
+            break;
+        }
+        case SYSCALL_ID_GETPID: {
+            ret = processGetId(getCurrentThread()->process);
+            break;
+        }
+        case SYSCALL_ID_GETTID: {
+            ret = threadGetId(getCurrentThread());
+            break;
+        }
+        case SYSCALL_ID_THREAD_JOIN: {
+            thread_id_t tid;
+
+            ret = syscallGet1arg(userCtx, (unsigned int *)&tid);
+            if (ret)
+                break;
+            ret = processJoinThread(getCurrentThread()->process, tid); 
+            break;
+        }
         default:
             printf("Unknon syscall id %d\n", syscallId);
             ret = -ENOENT;

core/syscall.h

@@ -11,6 +11,11 @@
 #define SYSCALL_ID_BRK 6
 #define SYSCALL_ID_MMAP 7
 #define SYSCALL_ID_MUNMAP 8
+#define SYSCALL_ID_NEW_THREAD 9
+#define SYSCALL_ID_USLEEP 10
+#define SYSCALL_ID_GETPID 11
+#define SYSCALL_ID_GETTID 12
+#define SYSCALL_ID_THREAD_JOIN 13
 
 #ifdef __KERNEL__
 int syscallExecute(int syscallId, const struct cpu_state *user_ctx);

core/thread.c

@@ -12,6 +12,12 @@
 
 static struct thread *currentThread;
 static struct thread *threadWithTimeout;
+static thread_id_t nextTid; // This is the TID for kernel thread ONLY
+
+pid_t threadGetId(struct thread *th)
+{
+    return th->tid;
+}
 
 static void threadPrepareContext(struct thread *th);
 
@@ -83,7 +89,9 @@ struct thread *threadCreate(const char *name, cpu_kstate_function_arg1_t func, v
                         (cpu_kstate_function_arg1_t *)threadExit, 0))
         goto free_mem;
 
-    thread->state = READY;
+    thread->state  = READY;
+    thread->tid    = nextTid++;
+    thread->wqExit = NULL;
     uint32_t flags;
     disable_IRQs(flags);
     list_add_tail(currentThread, thread);
@@ -110,6 +118,14 @@ struct thread *threadCreateUser(const char *name, struct process *proc, uaddr_t
     }
     thread->stackSize = THREAD_DEFAULT_STACK_SIZE;
 
+    thread->wqExit = (struct wait_queue * )malloc(sizeof(struct wait_queue));
+    if (!thread->wqExit) {
+        free((void *)thread->stackAddr);
+        free(thread);
+        return NULL;
+    }
+    waitQueueInit(thread->wqExit);
+
     if (name)
         strzcpy(thread->name, name, THREAD_NAME_MAX_LENGTH);
     else
@@ -124,6 +140,7 @@ struct thread *threadCreateUser(const char *name, struct process *proc, uaddr_t
         goto free_mem;
 
     thread->state = READY;
+    thread->tid = processGetNextTid(proc);
     uint32_t flags;
     disable_IRQs(flags);
     list_add_tail(currentThread, thread);
@@ -143,9 +160,14 @@ void threadDelete(struct thread *thread)
     restore_IRQs(flags);
     assert(thread->state == EXITING);
 
-    if (thread->squattedContext) {
+    if (thread->wqExit) {
-        threadChangeCurrentContext(NULL);
+        waitUp(thread->wqExit);
     }
+
+    if (thread->squattedContext) {
+        mmuContextUnref(thread->squattedContext);
+    }
+
     if (thread->process)
         processRemoveThread(thread);
 
@@ -292,6 +314,11 @@ int threadYield()
 }
 
 int threadMsleep(unsigned long msec)
+{
+    return threadUsleep(msec*1000);
+}
+
+int threadUsleep(unsigned long usec)
 {
     uint32_t flags;
     struct thread *next, *current;
@@ -299,12 +326,14 @@ int threadMsleep(unsigned long msec)
     disable_IRQs(flags);
 
     current = currentThread;
-    assertmsg(current->state == RUNNING, "thread %s is in state %d for %lu\n", current->name,
+    assertmsg(current->state == RUNNING, "thread %s is in state %d for %lu us\n", current->name,
-              current->state, msec);
+              current->state, usec);
 
     current->state              = SLEEPING;
     current->sleepHaveTimeouted = 0;
-    current->jiffiesSleeping    = msecs_to_jiffies(msec);
+    current->jiffiesSleeping    = usecs_to_jiffies(usec);
+    if (!current->jiffiesSleeping) // sleep at least 1 jiffies
+        current->jiffiesSleeping = 1;
     next                        = threadSelectNext();
 
     assert(next != current);

core/thread.h

@@ -4,6 +4,7 @@ struct thread;
 #include "cpu_context.h"
 #include "mem.h"
 #include "process.h"
+#include "wait.h"
 
 #define THREAD_NAME_MAX_LENGTH 32
 #define THREAD_DEFAULT_STACK_SIZE PAGE_SIZE
@@ -17,8 +18,11 @@ typedef enum {
     EXITING
 } thread_state;
 
+typedef unsigned long int thread_id_t;
+
 struct thread {
     char name[THREAD_NAME_MAX_LENGTH];
+    thread_id_t tid;
     struct cpu_state *cpuState;
     thread_state state;
     vaddr_t stackAddr;
@@ -32,6 +36,7 @@ struct thread {
     // For User thread only
     struct thread *nextInProcess, *prevInProcess;
     struct process *process;
+    struct wait_queue *wqExit; // This will be signaled at thread exit (user only)
 
   /**
    * Address space currently "squatted" by the thread, or used to be
@@ -83,8 +88,10 @@ int threadYield();
 int threadWait(struct thread *current, struct thread *next, unsigned long msec);
 int threadUnsched(struct thread *th);
 int threadMsleep(unsigned long msec);
+int threadUsleep(unsigned long usec);
 int threadOnJieffiesTick();
 struct thread *getCurrentThread();
 int threadAddThread(struct thread *th);
 int threadChangeCurrentContext(struct mmu_context *ctx);
 int threadCount();
+thread_id_t threadGetId(struct thread *th);

core/uaddrspace.h

@@ -1,8 +1,9 @@
 #pragma once
 #include "mmuContext.h"
 #include "process.h"
+#include "stddef.h"
+#include "stdint.h"
 #include "types.h"
-#include <stddef.h>
 
 struct uAddrSpace;
 struct uAddrVirtualReg;

debug.iso.gdb

@@ -0,0 +1,10 @@
+add-symbol-file userspace/user
+# Thx to add-gnu-debuglink gdb should know that symbols are in kernel.debug.
+# And by default, it should be looking at executable.debug
+# But we still have to give him the executable he is suppose to debug (See https://sourceware.org/gdb/current/onlinedocs/gdb.html/Separate-Debug-Files.html)
+#add-symbol-file kernel.debug
+file kernel
+source custom_gdb_extension.py
+#For ASM sources
+directory arch/x86/:core
+target remote | qemu-system-i386 -S -gdb stdio -m 16M -serial file:serialOut -hda fd.iso -hdb disk.img

drivers/ata.c

@@ -521,6 +521,19 @@ struct ata_partition *ATAGetPartition(int id)
 	return NULL;
 }
 
+struct ata_partition *ATAGetPartitionByType(uint type)
+{
+    struct ata_partition *part;
+    int count;
+    list_foreach(partitions, part, count)
+    {
+        if (part->type == type)
+            return part;
+    }
+
+    return NULL;
+}
+
 struct ata_partition *ATAPartitionCreate(uint type, uint size, uint32_t lba,
 					 struct ata_device *dev)
 {

drivers/ata.h

@@ -104,5 +104,6 @@ int ATAReadPartitionSector(struct ata_partition *part, int offset, uint nbSector
 int ATAReadSector(struct ata_device *dev, int lba, uint nbSector, void *buf);
 int ATAWriteSector(struct ata_device *dev, int lba, uint nbSector, void *buf);
 struct ata_device *ATAGetDevice(int ctlId, int devId);
+struct ata_partition *ATAGetPartitionByType(uint type);
 int ATAReadPartition(struct ata_device *dev);
 struct ata_partition *ATAGetPartition(int id);

drivers/zero.c

@@ -3,6 +3,7 @@
 #include "alloc.h"
 #include "kernel.h"
 #include "klibc.h"
+#include "mem.h"
 
 struct zeroMappedEntry {
     int refCnt;

userspace/kernel/syscall.h

@@ -11,6 +11,11 @@
 #define SYSCALL_ID_BRK 6
 #define SYSCALL_ID_MMAP 7
 #define SYSCALL_ID_MUNMAP 8
+#define SYSCALL_ID_NEW_THREAD 9
+#define SYSCALL_ID_USLEEP 10
+#define SYSCALL_ID_GETPID 11
+#define SYSCALL_ID_GETTID 12
+#define SYSCALL_ID_THREAD_JOIN 13
 
 #ifdef __KERNEL__
 int syscallExecute(int syscallId, const struct cpu_state *user_ctx);

userspace/libc.c

@@ -5,6 +5,8 @@
 #include "swintr.h"
 #include "sys/mman.h"
 #include "syscall.h"
+#include "thread.h"
+#include "unistd.h"
 
 int errno = 0;
 int memcmp(const void *aptr, const void *bptr, size_t size)
@@ -263,8 +265,57 @@ int puts(const char *str)
         return ret;                                                                           \
     }
 
+#define PRINT_UINT(name, type)                                                                \
+    int print##name(type integer, char *str, size_t size)                                     \
+    {                                                                                         \
+        char num[sizeof(integer) * 3];                                                        \
+        int i   = 0;                                                                          \
+        int c   = 0;                                                                          \
+        int ret = 0;                                                                          \
+                                                                                              \
+        do {                                                                                  \
+            int digit = integer % 10;                                                         \
+            num[i++]  = (digit > 0) ? digit : -digit;                                         \
+            integer   = integer / 10;                                                         \
+        } while (integer != 0);                                                               \
+                                                                                              \
+        for (i = i - 1; i >= 0; i--) {                                                        \
+            if (str) {                                                                        \
+                if (size) {                                                                   \
+                    str[c++] = num[i] + '0';                                                  \
+                    size--;                                                                   \
+                    ret++;                                                                    \
+                } else {                                                                      \
+                    return ret;                                                               \
+                }                                                                             \
+            } else {                                                                          \
+                ret++;                                                                        \
+            }                                                                                 \
+        }                                                                                     \
+        return ret;                                                                           \
+    }
+
 PRINT_INT(Int, int);
-PRINT_INT(Int64, long long int);
+PRINT_INT(Lint, long int);
+PRINT_INT(Llint, long long int);
+PRINT_UINT(Uint, unsigned int);
+PRINT_UINT(Luint, long unsigned int);
+PRINT_UINT(Lluint, long long unsigned int);
+
+#define PRINT_PART(func, type, str, size, c, ret)                                             \
+    {                                                                                         \
+        int s;                                                                                \
+        type d = va_arg(ap, type);                                                            \
+        if (str)                                                                              \
+            s = func(d, &str[c], size);                                                       \
+        else                                                                                  \
+            s = func(d, NULL, size);                                                          \
+                                                                                              \
+        size -= s;                                                                            \
+        c += s;                                                                               \
+        ret += s;                                                                             \
+        break;                                                                                \
+    }
 
 int vsnprintf(char *str, size_t size, const char *format, va_list ap)
 {
@@ -272,24 +323,13 @@ int vsnprintf(char *str, size_t size, const char *format, va_list ap)
     int i   = 0;
     int c   = 0;
 
-    while (format[i] != '\0' && (size || !str)) {
+    while (format[i] != '\0' && (size|| !str)) {
         switch (format[i]) {
             case '%':
                 switch (format[i + 1]) {
                     case 'i':
-                    case 'd': {
+                    case 'd': PRINT_PART(printInt, int, str, size, c, ret)
-                        int s;
+                    case 'u': PRINT_PART(printUint, uint, str, size, c, ret)
-                        int d = va_arg(ap, int);
-                        if (str)
-                            s = printInt(d, &str[c], size);
-                        else
-                            s = printInt(d, NULL, size);
-
-                        size -= s;
-                        c += s;
-                        ret += s;
-                        break;
-                    }
                     case 'p':
                     case 'x': {
                         char val[sizeof(int) * 2];
@@ -350,24 +390,15 @@ int vsnprintf(char *str, size_t size, const char *format, va_list ap)
                         switch (format[i + 2]) {
                             case 'l':
                                 switch (format[i + 3]) {
-                                    case 'd': {
+                                    case 'i':
-                                        int s;
+                                    case 'd': PRINT_PART(printLlint, long long int, str, size, c, ret)
-                                        long long int d = va_arg(ap, long long int);
+                                    case 'u': PRINT_PART(printLluint, long long unsigned int, str, size, c, ret)
-                                        if (str)
-                                            s = printInt64(d, &str[c], size);
-                                        else
-                                            s = printInt64(d, NULL, size);
-
-                                        size -= s;
-                                        c += s;
-                                        ret += s;
-                                        break;
-                                    }
                                     case 'p':
                                     case 'x': {
                                         char val[sizeof(long long int) * 2];
                                         unsigned int valIdx = 0;
-                                        long long int d     = va_arg(ap, long long int);
+                                        unsigned long long int d =
+                                            va_arg(ap, unsigned long long int);
                                         itoa(d, val, 16);
                                         if (str) {
                                             while (val[valIdx]) {
@@ -388,17 +419,28 @@ int vsnprintf(char *str, size_t size, const char *format, va_list ap)
                                 i++;
                                 break;
                             case 'i':
-                            case 'd': {
+                            case 'd': PRINT_PART(printLint, long int, str, size, c, ret)
-                                int s;
+                            case 'u':
-                                long int d = va_arg(ap, long int);
+                                PRINT_PART(printLuint, long unsigned int, str, size, c, ret)
-                                if (str)
+                            case 'p':
-                                    s = printInt64(d, &str[c], size);
+                            case 'x': {
-                                else
+                                char val[sizeof(int) * 2];
-                                    s = printInt64(d, NULL, size);
+                                unsigned int valIdx = 0;
-
+                                unsigned long int d = va_arg(ap, unsigned long int);
-                                size -= s;
+                                itoa(d, val, 16);
-                                c += s;
+                                if (str) {
-                                ret += s;
+                                    while (val[valIdx]) {
+                                        if (size) {
+                                            str[c++] = val[valIdx++];
+                                            size--;
+                                            ret++;
+                                        } else {
+                                            return ret;
+                                        }
+                                    }
+                                } else {
+                                    ret += strlen(val);
+                                }
                                 break;
                             }
                         }
@@ -745,3 +787,40 @@ int munmap(void *addr, size_t len)
 
     return syscall2(SYSCALL_ID_MUNMAP, (unsigned int)addr, len);
 }
+
+/* As when a new thread is run, the params are passed by register (See cpu_ustate_init), use
+ * this function to simplify new thread usage*/
+static void thread_runner()
+{
+    register unsigned long int reg_arg1 asm("%eax");
+    register unsigned long int reg_arg2 asm("%ebx");
+
+    start_routine *func = (start_routine *)reg_arg1;
+    void *arg           = (void *)reg_arg2;
+
+    func(arg);
+    _exit(0);
+}
+
+int thread_create(pthread_t *thread, start_routine *func, void *arg, size_t stackSize) {
+    return syscall5(SYSCALL_ID_NEW_THREAD, (unsigned int)thread, (unsigned int)thread_runner, (unsigned int)func,
+                    (unsigned int)arg, stackSize);
+}
+
+int thread_join(pthread_t thread, void **retval){
+    (void)retval;
+    return syscall1(SYSCALL_ID_THREAD_JOIN, (unsigned int)thread);
+}
+
+
+int usleep(useconds_t usec) {
+    return syscall1(SYSCALL_ID_USLEEP, (unsigned int)usec);
+}
+
+pid_t gettid(void) {
+    return syscall0(SYSCALL_ID_GETTID);
+}
+
+pid_t getpid(void) {
+    return syscall0(SYSCALL_ID_GETPID);
+}

userspace/libc.h

@@ -4,6 +4,7 @@
 #include "stdint.h"
 #include "stddef.h"
 #include "minmax.h"
+#include "unistd.h"
 
 #define islower(c) (('a' <= (c)) && ((c) <= 'z'))
 #define isupper(c) (('A' <= (c)) && ((c) <= 'Z'))
@@ -63,3 +64,6 @@ void *malloc(size_t size);
 void *calloc(size_t nmemb, size_t size);
 void *realloc(void *ptr, size_t size);
 void free(void *ptr);
+pid_t gettid(void);
+pid_t getpid(void);
+

userspace/main_user.c

@@ -3,7 +3,9 @@
 #include "stdarg.h"
 #include "stddef.h"
 #include "sys/mman.h"
+#include "thread.h"
 #include "tiny.h"
+#include "unistd.h"
 
 int func_help()
 {
@@ -15,6 +17,7 @@ int func_help()
         printf("        tiny: a tiny C-like interpreter\n");
         printf("        mmap: test mmap \n");
         printf("        munmap: test munmap \n");
+        printf("        thread: run a user thread\n");
         return 0;
 }
 
@@ -118,11 +121,28 @@ int func_munmap()
         return ret;
 }
 
-int main(int argc, char *argv[])
+static void *print_hello(void *arg) {
-{
+        (void)arg;
+        printf("Hello World from thread %lu\n", gettid());
+        usleep(100);
+
+        return NULL;
+}
+
+int func_thread() {
+        pthread_t id;
+        void *retval;
+        thread_create(&id, print_hello, NULL, 4096);
+        thread_join(id, &retval);
+
+        return 0;
+}
+
+int main(int argc, char *argv[]) {
         (void)argc;
         (void)argv;
         char buf[64];
+        assert(getpid() == gettid());
         printf("Shell starting... type \"help\" for help\n");
         while (1) {
                 printf(">");
@@ -145,7 +165,10 @@ int main(int argc, char *argv[])
                         continue;
                 }
                 if (strcmp(buf, "tiny") == 0) {
-                        func_tiny();
+                        pthread_t id;
+                        void *retval;
+                        thread_create(&id, func_tiny, NULL, 4096);
+                        thread_join(id, &retval);
                         continue;
                 }
                 if (strcmp(buf, "mmap") == 0) {
@@ -156,6 +179,10 @@ int main(int argc, char *argv[])
                         func_munmap();
                         continue;
                 }
+                if (strcmp(buf, "thread") == 0) {
+                        func_thread();
+                        continue;
+                }
         }
         return 0;
 }

userspace/thread.h

@@ -0,0 +1,8 @@
+#pragma once
+#include <stddef.h>
+
+typedef unsigned long int pthread_t;
+typedef void *(start_routine)(void *);
+int thread_create(pthread_t *thread, start_routine *func, void *arg, size_t stackSize);
+/* retval is ignored ATM */
+int thread_join(pthread_t thread, void **retval);

userspace/tiny.c

@@ -282,8 +282,9 @@ void run()
 
 /* Main program. */
 
-int func_tiny()
+void * func_tiny(void *args)
 {
+  (void)args;
     printf("Enter your program then ESC\n\n");
     printf("TinyC grammar\n");
     printf("<program> ::= <statement>\n");

userspace/tiny.h

@@ -1,4 +1,4 @@
 #pragma once
 
 
-int func_tiny();
+void * func_tiny(void *args);

userspace/unistd.h

@@ -0,0 +1,6 @@
+#pragma once
+
+typedef unsigned int useconds_t;
+int usleep(useconds_t usec);
+
+typedef unsigned long int pid_t;