very buggy fork, execve and exit

9 files changed, 224 insertions, 193 deletions

diff --git a/asm/int_syscall_handler.asm b/asm/int_syscall_handler.asm
index 89f152b..504d3e8 100644
--- a/asm/int_syscall_handler.asm
+++ b/asm/int_syscall_handler.asm
@@ -1,5 +1,7 @@
 global int_syscall_handler
 [extern task_fork]
+[extern task_exit]
+
 
 [extern syscall_exit]
 [extern syscall_write]
@@ -23,17 +25,19 @@ pid: dd 0x0
 
 int_syscall_handler:
 
+
 cmp eax, 72
 je call_fork
 
+cmp eax, 60
+je call_exit
+
  cli
 
     push ebx
     push ecx
     push edx
 
-    cmp eax, 60
-    je call_exit
 
     cmp eax, 61
     je call_write
@@ -78,12 +82,6 @@ je call_fork
 
 done:
 
-    mov ebx,eax 
-
-    mov al, 0x20   ;Port number AND command number to Acknowledge IRQ
-    out 0x20, al     ;Acknowledge IRQ, so we keep getting interrupts
-
-    mov eax,ebx 
 
 
 done_blocking:
@@ -98,6 +96,27 @@ done_blocking:
 
     iret           ;Interrupt-Return
 
+call_exit:
+
+    cli
+
+    pusha          ;Push all standard registers
+
+    mov esp, 0x7000	;now put the stack outside of virtual memory in kernel space!
+
+    push ebx      ;Push pointer to all the stuff we just pushed
+
+    call task_exit ;Call C code
+
+    mov esp, eax   ;Replace the stack with what the C code gave us
+
+    popa           ;Put the standard registers back
+
+    sti
+
+    iretd           ;Interrupt-Return
+    ;;;;
+
 call_fork:
 
     cli
@@ -113,9 +132,6 @@ call_fork:
 
     mov esp, ebx   ;Replace the stack with what the C code gave us
     
-    mov al, 0x20   ;Port number AND command number to Acknowledge IRQ
-    out 0x20, al   ;Acknowledge IRQ, so we keep getting interrupts
-
 
     popa           ;Put the standard registers back
 
@@ -166,9 +182,6 @@ call_sbrk:
     call syscall_sbrk
     jmp done
 
-call_exit:
-    call syscall_exit
-    jmp done
 
 call_unhandled:
     call syscall_unhandled
@@ -189,10 +202,24 @@ call_read:
 
 call_execve:
 
-    mov al, 0x20   ;Port number AND command number to Acknowledge IRQ
-    out 0x20, al     ;Acknowledge IRQ, so we keep getting interrupts
-    sti
+    pusha
+
+    mov eax,esp
+    mov esp,0x7000
+
+    push ebx
+    push ecx
+    push edx
 
+    mov ebx,eax
     call syscall_execve
-    jmp done_blocking
 
+    pop eax
+    pop eax
+    pop eax
+
+    mov esp,ebx
+
+    popa
+
+    jmp done
diff --git a/fs/elf.c b/fs/elf.c
index 3b2f2b3..57c9009 100644
--- a/fs/elf.c
+++ b/fs/elf.c
@@ -1,5 +1,8 @@
 #include <stdint.h>
+#include "ext2.h"
+#include "lib/logger/log.h"
 
+#define FOOLOS_MODULE_NAME "elf"
 #define EI_NIDENT 16
 
 
@@ -62,3 +65,102 @@ typedef struct {
        Elf32_Word      p_align;
 } 
 Elf32_Phdr;
+
+// returns elf entry point
+uint32_t load_elf(char *name, uint32_t *alloc)
+{
+
+    int inode_nr=ext2_filename_to_inode(EXT2_RAM_ADDRESS,name);
+    if(inode_nr<1)return 0;
+
+    //TODO: load ELF binary and move this to own compilation unit
+    
+    //load binary
+    uint32_t vaddr=0x08048000;
+
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"loading");
+    ext2_check(EXT2_RAM_ADDRESS);
+    ext2_inode_content(EXT2_RAM_ADDRESS,inode_nr,vaddr,0x100000); // load 1mb;
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"ELF File loaded to final destination.");
+
+    Elf32_Ehdr *elf;
+    elf=vaddr;
+
+    if(elf->e_ident[0]!=0x7f||elf->e_ident[1]!='E'||elf->e_ident[2]!='L'||elf->e_ident[3]!='F')
+	panic(FOOLOS_MODULE_NAME,"ELF mismatch!?");
+
+    
+    /*
+    log(FOOLOS_MODULE_NAME, FOOLOS_LOG_INFO, 
+	    "elf id: class=%d, data=%d, version=%d osabi=%d abiv=%d ",
+	    elf->e_ident[4],elf->e_ident[5],elf->e_ident[6],
+	    elf->e_ident[7],elf->e_ident[8]);
+
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf type: 0x%04x",elf->e_type);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf machine: 0x%04x",elf->e_machine);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf version: %d",elf->e_version);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf entry: 0x%08X",elf->e_entry);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf ph-offset: 0x%08X",elf->e_phoff);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf sh-offset: 0x%08X",elf->e_shoff);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf flags: 0x%08X",elf->e_flags);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf eh-size (bytes): %d",elf->e_ehsize);
+
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf ph-ent-size(bytes): %d",elf->e_phentsize);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf ph-num: %d",elf->e_phnum);
+
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf sh-ent-size(byte): %d",elf->e_shentsize);
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf sh-num: %d",elf->e_shnum);
+
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf sh-strndx: %d",elf->e_shstrndx);
+    */
+
+    // iterate over section headers
+    for(int phidx=0;phidx<elf->e_phnum;phidx++)
+    {	
+	Elf32_Phdr *phdr=vaddr+elf->e_phoff+phidx*elf->e_phentsize;
+
+	if(phidx==0)
+	{
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"text: 0x%08X-0x%08X",phdr->p_vaddr,phdr->p_vaddr+phdr->p_filesz);
+	}
+
+	if(phidx==1)
+	{
+
+
+	    /*
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"-- PROGRAMM HEADER %d --",phidx+1);
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-type: %d",phdr->p_type);
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-offset: 0x%08X",phdr->p_offset);
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-vaddr: 0x%08X",phdr->p_vaddr);
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-filesz: 0x%08X",phdr->p_filesz);
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-memsz: 0x%08X",phdr->p_memsz);
+	    */
+	    
+	    
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"data: 0x%08X-0x%08X",phdr->p_vaddr,phdr->p_vaddr+phdr->p_filesz);
+	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"bss: 0x%08X-0x%08X",phdr->p_vaddr+phdr->p_filesz,phdr->p_vaddr+phdr->p_memsz);
+
+	    // let's copy the rw- data block
+	    uint32_t *data=vaddr+phdr->p_offset;
+	    for(uint32_t *addr=phdr->p_vaddr; addr<=phdr->p_vaddr+phdr->p_filesz; addr++)
+	    {
+		*addr=*data;
+		data++;
+	    }
+
+	    // let's zero init bss and set alloc (heap) just right after it! 
+	    for(uint32_t *addr=phdr->p_vaddr+phdr->p_filesz; addr<=phdr->p_vaddr+phdr->p_memsz; addr++)
+	    {
+		*addr=0;
+	    }
+
+	    *alloc=phdr->p_vaddr+phdr->p_memsz;
+	}
+
+
+    }
+
+    return elf->e_entry;
+
+}
diff --git a/fs/ext2.h b/fs/ext2.h
index 1307347..07f4153 100644
--- a/fs/ext2.h
+++ b/fs/ext2.h
@@ -1,4 +1,5 @@
 #include  <stdint.h>
+#include  "fs.h"
 int ext2_check(uint8_t *ram);
 int ext2_inode_content(char *ram,int inode_nr,uint8_t *ramdest,int max);
 int ext2_read_dir(uint8_t *ram, int inode_nr,fs_dirent *dirs,int max);
diff --git a/kernel/kernel.c b/kernel/kernel.c
index a0aaa7f..641c442 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -85,11 +85,19 @@ void kernel_main(uint32_t initial_stack, int mp)
     int_init(0x08);
 
     //
+    // Scan the PCI Bus
+    // 
+    // We are interested in the E1000 Network Adapter in particular
+    // Its driver will be hopefully implemented one day ;) TODO
+    //
+    //pci_init();
+   
+
+    //
     // Gather Info about other processors. (APs)
     // ACPI or MP
     //
     //
-
     /*
     smp_processors procdata;    
 
@@ -97,48 +105,22 @@ void kernel_main(uint32_t initial_stack, int mp)
 	if(!mp_find(&procdata))
 	    panic(FOOLOS_MODULE_NAME,"ACPI and MP search failed! I do not want to continue!");
     */
-
-    task_init(); //; this will never return!
-
-   
-    // load and run foolshell
-    // we will come back into the kernel only on interrupts...
-/*
-    
-    static char *argv[]={"/bin/foolshell",NULL};
-    static char *env[]={"PATH=/bin","PWD=/home/miguel","PS1=$ ",NULL};
-    syscall_execve("/bin/foolshell",argv,env); 
-  */  
-
-
     // 
     // Start the other Processors (also before paging for some reason!)
     //
     //smp_log_procdata(&procdata);
     //smp_start_aps(&procdata,0x80000);	// starts at 0x80000 
 					// but it will be copied over mbr
-					
-
-    //
-    // Scan the PCI Bus
-    // 
-    // We are interested in the E1000 Network Adapter in particular
-    // Its driver will be hopefully implemented one day ;) TODO
-    //
-    //pci_init();
 
     //
     // Initialize Multitasking
     //
-    // For now this starts three "tasks" which are scheduled 
-    // round robin style.
-    //
+    
+    task_init(); //; this will never return!
 
-    //task_init();
+   
+					
 
-    // Just hang around here, if its reached. 
-    // we do our tasks anyway. on the next clock tick.
-    // while(1);
    
  
 }
diff --git a/kernel/syscalls.c b/kernel/syscalls.c
index 7bdb639..41d77ec 100644
--- a/kernel/syscalls.c
+++ b/kernel/syscalls.c
@@ -8,9 +8,8 @@
 #include "kernel/console.h"
 #include "kernel/config.h"
 #include <sys/stat.h>
-#include "fs/elf.c"
 
-static uint32_t alloc;
+static uint32_t alloc; // TODO: implement on a per process basis!
 
 int syscall_unhandled(int nr)
 {
@@ -20,7 +19,6 @@ int syscall_unhandled(int nr)
 
 int syscall_lseek(int file,int ptr,int dir) 
 {
-
     #ifdef LOG_SYSCALLS
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"lseek (file=%d, ptr=%d, dir=%d)", file,ptr,dir);
     #endif
@@ -31,6 +29,8 @@ int syscall_lseek(int file,int ptr,int dir)
 
 }
 
+
+// TODO: /dev/console or /dev/tty1 - /dev/ttyN
 int syscall_write(int file, char *buf, int len)
 {
 
@@ -50,7 +50,7 @@ int syscall_write(int file, char *buf, int len)
     return len;
 }
 
-
+// TODO: /dev/kb
 int syscall_read(int file, char *buf, int len)
 {
     static bool eof=false;
@@ -125,20 +125,8 @@ int syscall_wait(int *wait, int none1, int none2)
     #ifdef LOG_SYSCALLS
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"[%d] wait ",task_get_current_pid());
     #endif
-}
-
-int syscall_fork(int none, int none2, int none3)
-{
-    //int pid=add_task(esp,vmem_new_space_dir()); 
-    int pid=task_get_current_pid();
-    int esp=0;
-
-    #ifdef LOG_SYSCALLS
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"[%d] fork: current esp: 0x%08X, pid: %d ",task_get_current_pid(),esp,pid);
-    #endif
-
-    return 0;
 
+    panic(FOOLOS_MODULE_NAME,"unhandled syscall");
 }
 
 int syscall_execve(char *name, char **argv1, char **env1)
@@ -149,96 +137,12 @@ int syscall_execve(char *name, char **argv1, char **env1)
     #ifdef LOG_SYSCALLS
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"execve (name=0x%08X(%s), argvs=0x%08X,  env=0x%08X)", name,name,argv,env);
     #endif
-
-    int inode_nr=ext2_filename_to_inode(EXT2_RAM_ADDRESS,name);
-    if(inode_nr<1)return -1;
-
-    //TODO: load ELF binary and move this to own compilation unit
     
-    //load binary
-    uint32_t vaddr=0x08048000;
-
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"loading");
-    ext2_check(EXT2_RAM_ADDRESS);
-    ext2_inode_content(EXT2_RAM_ADDRESS,inode_nr,vaddr,0x100000); // load 1mb;
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"ELF File loaded to final destination.");
-
-    Elf32_Ehdr *elf;
-    elf=vaddr;
-
-    if(elf->e_ident[0]!=0x7f||elf->e_ident[1]!='E'||elf->e_ident[2]!='L'||elf->e_ident[3]!='F')
-	panic(FOOLOS_MODULE_NAME,"ELF mismatch!?");
-
-    
-    /*
-    log(FOOLOS_MODULE_NAME, FOOLOS_LOG_INFO, 
-	    "elf id: class=%d, data=%d, version=%d osabi=%d abiv=%d ",
-	    elf->e_ident[4],elf->e_ident[5],elf->e_ident[6],
-	    elf->e_ident[7],elf->e_ident[8]);
-
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf type: 0x%04x",elf->e_type);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf machine: 0x%04x",elf->e_machine);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf version: %d",elf->e_version);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf entry: 0x%08X",elf->e_entry);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf ph-offset: 0x%08X",elf->e_phoff);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf sh-offset: 0x%08X",elf->e_shoff);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf flags: 0x%08X",elf->e_flags);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf eh-size (bytes): %d",elf->e_ehsize);
-
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf ph-ent-size(bytes): %d",elf->e_phentsize);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf ph-num: %d",elf->e_phnum);
-
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf sh-ent-size(byte): %d",elf->e_shentsize);
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf sh-num: %d",elf->e_shnum);
-
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"elf sh-strndx: %d",elf->e_shstrndx);
-    */
-
-    // iterate over section headers
-    for(int phidx=0;phidx<elf->e_phnum;phidx++)
-    {	
-	Elf32_Phdr *phdr=vaddr+elf->e_phoff+phidx*elf->e_phentsize;
-
-	if(phidx==0)
-	{
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"text: 0x%08X-0x%08X",phdr->p_vaddr,phdr->p_vaddr+phdr->p_filesz);
-	}
-
-	if(phidx==1)
-	{
-
-
-	    /*
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"-- PROGRAMM HEADER %d --",phidx+1);
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-type: %d",phdr->p_type);
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-offset: 0x%08X",phdr->p_offset);
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-vaddr: 0x%08X",phdr->p_vaddr);
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-filesz: 0x%08X",phdr->p_filesz);
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"p-memsz: 0x%08X",phdr->p_memsz);
-	    */
-	    
-	    
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"data: 0x%08X-0x%08X",phdr->p_vaddr,phdr->p_vaddr+phdr->p_filesz);
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"bss: 0x%08X-0x%08X",phdr->p_vaddr+phdr->p_filesz,phdr->p_vaddr+phdr->p_memsz);
-
-	    // let's copy the rw- data block
-	    uint32_t *data=vaddr+phdr->p_offset;
-	    for(uint32_t *addr=phdr->p_vaddr; addr<=phdr->p_vaddr+phdr->p_filesz; addr++)
-	    {
-		*addr=*data;
-		data++;
-	    }
-
-	    // let's zero init bss and set alloc (heap) just right after it! 
-	    for(uint32_t *addr=phdr->p_vaddr+phdr->p_filesz; addr<=phdr->p_vaddr+phdr->p_memsz; addr++)
-	    {
-		*addr=0;
-	    }
-
-	    alloc=phdr->p_vaddr+phdr->p_memsz;
-	}
-
-
+    uint32_t entry=load_elf(name,&alloc);
+    if(!entry)
+    {
+	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"execve: bailing out!");
+	return -1; // errror loading
     }
 
  
@@ -261,8 +165,9 @@ int syscall_execve(char *name, char **argv1, char **env1)
     asm("push %0" :: "r" (env));
 
     // push addr and return to it
-    asm("push %0"::"r"(elf->e_entry));
+    asm("push %0"::"r"(entry));
     
+    asm("sti");
     asm("ret");
 
     // this is never reached!
@@ -276,7 +181,6 @@ int syscall_open(char *name, int flags, int mode)
     #endif
     panic(FOOLOS_MODULE_NAME,"unhandled syscall");
 
-
 }
 
 
@@ -304,6 +208,7 @@ int syscall_isatty(int file,int none1,int none2)
     return 1;
 }
 
+// TODO: per process basis!
 uint32_t syscall_sbrk(int incr, int none1, int none2) 
 {
     uint32_t oldalloc=alloc;
@@ -324,18 +229,6 @@ int syscall_exit(int ret, char **env, int none2)
 
     panic(FOOLOS_MODULE_NAME,"exit not supported yet" );
 
-    /*
-    int i=0;
-    while(env[i]!=NULL)
-    {
-        log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"envvar %s (0x%08X)\n" ,env[i],env[i]);
-	i++;
-    }
-
-    asm("mov $0x05bff,%esp"); // set stack pointer
-    static char *argv[]={"shell","--silent",NULL};
-    syscall_execve("/bin/foolshell",argv,env); // start shell
-    */
 }
 
 
diff --git a/kernel/task.c b/kernel/task.c
index 1780b77..6ea9b79 100644
--- a/kernel/task.c
+++ b/kernel/task.c
@@ -76,10 +76,31 @@ uint32_t task_switch_next(uint32_t oldesp)
 
 }
 
+//TODO: free vmem too!
+uint32_t task_exit(uint32_t oldesp)
+{ 
+    task_list[current_task].active=false;
+
+    for(int i=0;i<MAX_TASKS;i++)
+    {
+	int pid=(current_task+1+i)%MAX_TASKS; // schedule round robin style
+
+	if(task_list[pid].active)
+	{
+	  //  log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"switch from %d to pid: %d (0x%08X) vmem: %d ", current_task,pid,task_list[pid].esp,task_list[pid].vmem);
+	    current_task=pid;
+
+	    vmem_set_dir(task_list[pid].vmem);
+	    return task_list[pid].esp;
+	}
+
+    }
+}
 
 uint32_t task_fork(uint32_t oldesp)
 { 
-    return add_task(oldesp,vmem_new_space_dir());
+   int pid=add_task(oldesp,vmem_new_space_dir(task_list[current_task].vmem));
+   return pid;
 }
 
 // init task (root of all other tasks / processes) //
diff --git a/kernel/vmem.c b/kernel/vmem.c
index 0a9e4b1..0cea40b 100644
--- a/kernel/vmem.c
+++ b/kernel/vmem.c
@@ -254,7 +254,7 @@ uint32_t vmem_alloc_block_at(uint32_t virt_addr)
 */
 
 // vmem init and also copies all the shit for FORK 
-volatile int vmem_new_space_dir()
+volatile int vmem_new_space_dir(int copy_dir)
 {
     x86_paging_disable();
     
@@ -319,7 +319,7 @@ volatile int vmem_new_space_dir()
     {
 
 	ptable* table = (ptable*) pmmngr_alloc_block ();
-	pd_entry *oldentry= &(page_dirs[0]->m_entries[PAGE_DIRECTORY_INDEX(virt_addr)]);
+	pd_entry *oldentry= &(page_dirs[copy_dir]->m_entries[PAGE_DIRECTORY_INDEX(virt_addr)]);
 	ptable* oldtable=pd_entry_get_frame(oldentry);
 	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"oldtable at: 0x%08X",oldtable);
 
@@ -381,7 +381,7 @@ void vmem_init()
 {
     //log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"init paging (vesa base: 0x%08x)",vesa_physbase);
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"init paging");
-    vmem_set_dir(vmem_new_space_dir());
+    vmem_set_dir(vmem_new_space_dir(0));
     x86_paging_enable();
 
 }
diff --git a/userspace/foolshell.c b/userspace/foolshell.c
index e010c18..78ba327 100644
--- a/userspace/foolshell.c
+++ b/userspace/foolshell.c
@@ -16,12 +16,12 @@ void hello()
     "    / __/ / /_/ / /_/ / /  / /_/ /___/ /       \n"
     "   /_/    \\____/\\____/_/   \\____//____/     \n"
     "                                               \n"
-    "Welcome to FoolShell v0.4 (Compiled on " __DATE__ " at " __TIME__ "\n"
+    "Welcome to FoolShell v0.5 (Compiled on " __DATE__ " at " __TIME__ "\n"
     "------------------------------------------------------------------\n\n"
     "Please type 'help' anytime, to show shell \"built-ins\" or execute \n"
     "user programms that are in you $PATH directory by simply typing \n"
     "their filenames. You can get additional information for many commands\n"
-    "by invking them with the --help or -h flag (e.g. ls --help) \n"
+    "by invoking them with the --help or -h flag (e.g. ls --help) \n"
     );
 
     printf("Your $PATH is currently set to: %s\n\n",getenv("PATH"));
@@ -211,20 +211,16 @@ int process(char *buf)
     }
     else
     {
-	char buf[256];
-	sprintf(buf,"%s/%s",getenv("PATH"),token[0]);
-
-	asm("mov $0x05bff,%esp"); // set stack pointer
-	execve(buf,token,environ);
-	asm("mov $0x07000,%esp"); // set stack pointer
-
-	puts("foolshell: command not found");
-
-	asm("mov $0x05bff,%esp"); // set stack pointer
-	static char *argv[]={"shell","--silent",NULL};
-	execve("/bin/foolshell",argv,environ); // start shell
-	
-
+	int pid=fork();
+	if(pid!=0)
+	{
+	    printf("new task pid: %i \n",pid);
+	    char buf[256];
+	    sprintf(buf,"%s/%s",getenv("PATH"),token[0]);
+	    execve(buf,token,environ);
+	    puts("foolshell: command not found");
+	    exit(1);
+	}
 
     }
     return 0;
diff --git a/userspace/init.c b/userspace/init.c
index d03d173..fd562a9 100644
--- a/userspace/init.c
+++ b/userspace/init.c
@@ -1,12 +1,21 @@
 int main(int argc, char **argv)
 {
-    printf("Fool OS Init 0.1 \n");
-
     int pid=fork();
 
-    while(1)
+    if(pid!=0)
     {
-	printf("I am pid: %i\n",pid);
+	printf("fool-init: forked child (pid: %i) spawning a Fools Shell\n",pid);
+	execve("/bin/foolshell",0,0);
+
+    }
+    else
+    {
+	// TODO: wait for child and respawn shell if needed!
+	volatile int i=0;
+	while(1)
+	{
+
+	}
     }
     return 0;
 }