struggling with new multitasking

6 files changed, 62 insertions, 184 deletions

diff --git a/asm/int_clock_handler.asm b/asm/int_clock_handler.asm
index c6c91fc..7e55067 100644
--- a/asm/int_clock_handler.asm
+++ b/asm/int_clock_handler.asm
@@ -1,8 +1,6 @@
 global int_clock_handler
 [extern task_switch_next]
 
-;CLOCK_COUNTER:
-;    db 0x00
 
 [bits 32]
 int_clock_handler:
@@ -20,8 +18,8 @@ int_clock_handler:
 ; mov byte [CLOCK_COUNTER], 0x00
 
 pusha          ;Push all standard registers
- push esp       ;Push pointer to all the stuff we just pushed
 
+ push esp       ;Push pointer to all the stuff we just pushed
  call task_switch_next ;Call C code
 
  ;pop ebx
@@ -30,7 +28,6 @@ pusha          ;Push all standard registers
  ;cmp eax,ebx
  ;jne compare 
 
- 
  mov esp, eax   ;Replace the stack with what the C code gave us
 
  
diff --git a/kernel/config.h b/kernel/config.h
index fb68dec..4238578 100644
--- a/kernel/config.h
+++ b/kernel/config.h
@@ -8,7 +8,7 @@
 #define FOOLOS_CONFIG_H
 
 #define FOOLOS_CONSOLE_AUTOBREAK    // add newline automatically at end of line
-#define FOOLOS_LOG_OFF		    // do not log anything 
+//#define FOOLOS_LOG_OFF		    // do not log anything 
 #define FOOLOS_CONSOLE		    // otherwise VESA will be used!	
 #define MEM_PRINT_MEMORYMAP
 #define LOG_BUF_SIZE 4069
diff --git a/kernel/kernel.c b/kernel/kernel.c
index ed632c3..b03e3cd 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -67,7 +67,7 @@ void kernel_main(uint32_t initial_stack, int mp)
     //
     // Activate Virtual Memory (paging)
     // 0x8048000 is where user programms start!
-    vmem_init();
+    //vmem_init();
 
     //
     // init output to screen
@@ -107,8 +107,8 @@ void kernel_main(uint32_t initial_stack, int mp)
     */
 
 
-   // task_init();
-   // while(1);
+    task_init();
+    while(1);
    
     // load and run foolshell
     // we will come back into the kernel only on interrupts...
diff --git a/kernel/syscalls.c b/kernel/syscalls.c
index 765316b..585950d 100644
--- a/kernel/syscalls.c
+++ b/kernel/syscalls.c
@@ -72,7 +72,7 @@ typedef struct {
 } 
 Elf32_Phdr;
 
-static uint32_t alloc=0x900000;
+static uint32_t alloc;
 
 int syscall_unhandled(int nr)
 {
@@ -102,10 +102,9 @@ int syscall_write(int file, char *buf, int len)
 
     if(file!=1&&file!=2) panic(FOOLOS_MODULE_NAME,"unhandled syscall");
 
-    // ALL output to stdout
+    //stderr and stdout go to console
     for(int i=0;i<len;i++)
     {
-	//PutConsoleChar(buf[i],0b1111111111000000);
 	console_put_char_green(buf[i]);
     }
     return len;
@@ -180,9 +179,14 @@ int syscall_readdir(const char *name,fs_dirent *dirs,int max)
     return fs_readdir(name,dirs,max);
 }
 
+int syscall_fork()
+{
+}
 
 int syscall_execve(char *name, char **argv, char **env)
 {
+    // watchout this is called with esp in virtual memory of running process!
+
     #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
@@ -190,74 +194,6 @@ int syscall_execve(char *name, char **argv, char **env)
     int inode_nr=ext2_filename_to_inode(EXT2_RAM_ADDRESS,name);
     if(inode_nr<1)return -1;
 
-/*
-    char arg1[100];
-    char arg2[100];
-    char arg3[100];
-    char arg4[100];
-    char arg5[100];
-    char *argvcopy[]={arg1,arg2,arg3,arg4,arg5};
-
-    int argc=0;
-
-    if(argv!=NULL)
-    {
-	while(argv[argc]!=NULL)
-	{
-	    //log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"arg at 0x%08X: %s", argv[argc],argv[argc]);
-
-	    int i=-1;
-	    do{
-		    i++;
-        	    argvcopy[argc][i]=argv[argc][i];
-	    }while(argv[argc][i]!=0);
-
-	    argc++;
-	}
-    }
-    argvcopy[argc]=NULL;
-
-    //
-    char *env1="PS1=$ ";
-    char *env2="PATH=/bin";
-    char *env3="PWD=/home/miguel";
-    char environstr[256];
-
-    char **oldenviron=env;
-    char **environ=0xf00001;
-
-    if(oldenviron==0)
-    {
-	environ[0]=env1;
-	environ[1]=env2;
-	environ[2]=env3;
-	environ[3]=NULL;
-    }
-    else
-    {
-	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"environ: (0x%08X)",oldenviron);
-	int i=0;
-	int k=-1;
-	while(oldenviron[i]!=NULL)
-	{
-	    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"copy env: %s (0x%08X)",oldenviron[i],oldenviron[i]);
-	    int start=k+1;
-	    int j=-1;
-	    do{
-	    j++;
-	    k++;
-	    environstr[k]=oldenviron[i][j];
-	    }while(oldenviron[i][j]!=0);
-
-	    environ[i]=&environstr[start];
-	    i++;
-	}
-
-	environ[i]=NULL;
-    }
-    
-
-*/
     //TODO: load ELF binary and move this to own compilation unit
     
     //load binary
@@ -300,7 +236,6 @@ int syscall_execve(char *name, char **argv, char **env)
     */
 
     
-
     // iterate over section headers
     for(int phidx=0;phidx<elf->e_phnum;phidx++)
     {	
@@ -372,7 +307,6 @@ int syscall_execve(char *name, char **argv, char **env)
     asm("ret");
 
     // this is never reached!
-
 }
 
 
@@ -413,16 +347,13 @@ int syscall_isatty(int file,int none1,int none2)
 
 uint32_t syscall_sbrk(int incr, int none1, int none2) 
 {
-
     uint32_t oldalloc=alloc;
     alloc+=incr;
 
     #ifdef LOG_SYSCALLS
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"sbrk (incr=%d) = 0x%08X", incr,oldalloc);
     #endif
-
     return oldalloc;
-
 }
 
 
@@ -432,6 +363,9 @@ int syscall_exit(int ret, char **env, int none2)
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"exit (ret=%d) (env=0x%08X)", ret, env);
     #endif
 
+    panic(FOOLOS_MODULE_NAME,"exit not supported yet" );
+
+    /*
     int i=0;
     while(env[i]!=NULL)
     {
@@ -442,11 +376,11 @@ int syscall_exit(int ret, char **env, int none2)
     asm("mov $0x05bff,%esp"); // set stack pointer
     static char *argv[]={"shell","--silent",NULL};
     syscall_execve("/bin/foolshell",argv,env); // start shell
+    */
 }
 
 
 // stat, fstat, lstat
-
 int syscall_stat(const char *path, struct stat *st,int none)
 {
     #ifdef LOG_SYSCALLS
diff --git a/kernel/syscalls.h b/kernel/syscalls.h
index fc5f5bf..d9a338d 100644
--- a/kernel/syscalls.h
+++ b/kernel/syscalls.h
@@ -32,12 +32,13 @@
 #define SYSCALL_GETPID 78
 
 int syscall_execve(char *name, char **argv, char **env);
+int syscall_write(int file, char *buf, int len);
+
 /*
 int syscall_readdir(const char *name,struct fs_dirent *dirs,int max);
 
 int syscall_exit(int ret, int none1, int none2);
 int syscall_open(char *name, int flags, int len);
-int syscall_write(int file, char *buf, int len);
 int syscall_read(int file, char *buf, int len);
 int syscall_close(int file,int none1,int none2);
 int syscall_fstat(int file, struct stat *st,int none);
diff --git a/kernel/task.c b/kernel/task.c
index 08301cf..620977e 100644
--- a/kernel/task.c
+++ b/kernel/task.c
@@ -14,75 +14,27 @@
 #include "fs/ext2.h"
 #define FOOLOS_MODULE_NAME "task"
 
-int started;
-static volatile int c1,c2,c3;
 
-void task_test1()
-{
-    // simple built-in shell
-    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"spawning build-in shell");
-
-   while(1)
-   {
-    
-	char c;
-	if(ringbuffer_get(&c))
-	{
-	    console_put_char_white(c);
-	}
-    }
-
-    /*
-	c1++;
-	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"task 1 progress: %d", c1);
-	sleep(2);
-	*/
-
-   
-
-}
+#define MAX_TASKS 10
 
-void task_test2()
-{
-   while(1)
-   {
-       c2++;
-       //log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"task 2 progress: %d", c2);
-//	sleep(2);
-
-   }
+static volatile int current_task=-2;
 
-}
-
-void task_test3()
+static volatile struct task_list_struct
 {
-   while(1)
-   {
-       c3++;
-//	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"task 3 progress: %d", c3);
-//	sleep(2);
-   }
-
-}
-
-//////////////
-//
-typedef struct{        //Simple structure for a thread
-      unsigned int esp0;   //Stack for kernel
-        unsigned int esp3;   //Stack for process
-} Thread;
-
-
-Thread Threads[3];     //Space for our simple threads.
-volatile int CurrentTask;  //The thread currenlty running (-1 == none) 
+    bool active;
+    uint32_t esp; // stack pointer of the task;
+    uint32_t vmem; // number of virtual memory table to switch to
+    
+}task_list[MAX_TASKS];
 
 
 void task_create(int pid,void(*thread)())
 {
      unsigned int *stack;
 
-    Threads[pid].esp0 = pmmngr_alloc_block();
-    stack = (unsigned int*)Threads[pid].esp0+4095; //This makes a pointer to the stack for us
+    task_list[pid].esp = pmmngr_alloc_block();
+    stack = (unsigned int*)task_list[pid].esp+4095; //This makes a pointer to the stack for us
+
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"new task: stack: 0x%08X  thread: 0x%08X", stack, thread);
 
  //First, this stuff is pushed by the processor
@@ -108,60 +60,54 @@ void task_create(int pid,void(*thread)())
  *--stack = 0x10; //GS
  */
  
- Threads[pid].esp0 = (uint32_t)stack; //Update the stack pointer
-
+    task_list[pid].esp = (uint32_t)stack; //Update the stack pointer
+    task_list[pid].active=true;
 
 };
 
+// this gets called by our clock interrupt regularly!
 uint32_t task_switch_next(uint32_t oldesp)
 {
+    timer_tick();
 
-    //console_put_char('.');
-  timer_tick();
-  if(started!=0xabcde) return oldesp;
-  if(CurrentTask!=-1)Threads[CurrentTask].esp0=oldesp;
-
-  CurrentTask++;
-  if(CurrentTask>2)CurrentTask=0;
-
-  /*
-  log(
-    FOOLOS_MODULE_NAME,
-    FOOLOS_LOG_INFO,
-    "oldesp: 0x%08X saved / next task: %d (esp: 0x%08X) ",
-    oldesp, 
-    CurrentTask,
-    Threads[CurrentTask].esp0);
- 
-//  return oldesp;
-//  */
-
-  return Threads[CurrentTask].esp0; //Return new stack pointer to ASM
-}
+    if(current_task==-2)return oldesp;
+    if(current_task!=-1)task_list[current_task].esp=oldesp;
 
-void stack_trace(uint32_t *stack,int size)
-{
-    for(int i=size;i>=0;i--)
+    for(int i=0;i<MAX_TASKS;i++)
     {
-	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"stack: 0x%08X -> 0x%08X", stack, *stack);
-	stack++;
+	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)", current_task,pid,task_list[pid].esp);
+	    current_task=pid;
+	    return task_list[pid].esp;
+	}
 
     }
-}
-
-void task_init()
-{
 
+    // if no task found retunr the old esp
+    return oldesp;
+}
 
-   CurrentTask=-1;
+volatile int c1,c2;
 
-   log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"init multitasking.");
-   task_create(0,task_test1);
-   task_create(1,task_test2);
-   task_create(2,task_test3);
-   started=0xabcde;
+volatile void test1()
+{
+    c1++;
+   // syscall_write(1,">",1);
 }
 
+volatile void test2()
+{
+    c2++;
+  //  syscall_write(1,"<",1);
+}
+void task_init()
+{
+    task_create(1,test1);
+    task_create(2,test2);
+    current_task=-1;
+}