added execve syscall

1 files changed, 36 insertions, 76 deletions

diff --git a/userspace/syscalls.c b/userspace/syscalls.c
index 11976bc..b5959eb 100644
--- a/userspace/syscalls.c
+++ b/userspace/syscalls.c
@@ -10,36 +10,58 @@ static int preread;
 static int alloc;
 easywrite(char *c);
 
+// init syscalls 
 void syscalls_init()
 {
-    preread=0;
+    // TODO dynamic!
     alloc=0x300000;
 }
 
-//
+// generic syscall interface!
+int syscall(int call, int p1, int p2, int p3)
+{
+	int ebx; // will hold return value;
+
+	asm("pusha");
+
+	// select syscall
+	asm("mov %0, %%eax"::"m"(call)); 
+
+	// pass params
+	asm("mov %0,%%edx"::"m"(p1));
+	asm("mov %0,%%ecx"::"m"(p2));
+	asm("mov %0,%%ebx"::"m"(p3));
 
+	// interrrupt
+	asm("int $0x80");
+
+	// get return value
+        asm("mov %%ebx, %0": "=b" (ebx));
+
+	asm("popa");
+
+	return ebx;
+}
+
+//
 int close(int file) 
 {
-// easywrite("syscall: close\n");
     return -1;
 }
 
 int fstat(int file, struct stat *st)
 {
-//    easywrite("syscall: fstat\n");
     st->st_mode = S_IFCHR;
     return 0;
 }
 
 int isatty(int file) 
 {
-//  easywrite("syscall: isatty\n");
     return 1;
 }
 
 int lseek(int file, int ptr, int dir) 
 {
-//    printf("syscall: lseek %i %i %i",file,ptr,dir);
     if(dir==0)preread=ptr;
     else{ puts("other modes unsupported sorry"); while(1);}
     return preread;
@@ -47,86 +69,29 @@ int lseek(int file, int ptr, int dir)
 
 int read(int file, char *ptr, int len)
 {
-	int ebx; // will hold return value;
-
-	asm("pusha");
-
-	// select syscall
-	asm("mov $62,%eax"); 
-
-	// pass params
-	asm("mov %0,%%edx"::"m"(file));
-	asm("mov %0,%%ecx"::"m"(ptr));
-	asm("mov %0,%%ebx"::"m"(len));
-
-	// interrrupt
-	asm("int $0x80");
-
-	// get return value
-        asm("mov %%ebx, %0": "=b" (ebx));
-
-	asm("popa");
-
-	return ebx;
+    return syscall(62,file,ptr,len);
 }
 
 int readdir(const char *name,fs_dirent  *dirs,int max)
 {
 
-	int ebx; // WILL Hold return value;
-
-	asm("pusha");
-
-	// select syscall
-	asm("mov $63,%eax"); 
-
-	// pass params
-	asm("mov %0,%%edx"::"m"(name));
-	asm("mov %0,%%ecx"::"m"(dirs));
-	asm("mov %0,%%ebx"::"m"(max));
-
-	// interrrupt
-	asm("int $0x80");
-
-	// get return value
-        asm("mov %%ebx, %0": "=b" (ebx));
-
-	asm("popa");
-
-	return ebx;
+    return syscall(63,name,dirs,max);
 }
 
 int open(const char *name, int flags, int mode)
 {
-//   easywrite("syscall: open\n");
-    return 99;
-    return -1;
+    return name;
 }
 
 int write(int file, char *ptr, int len) 
 {
+    return syscall(61,file,ptr,len);
+}
 
-	int ebx; // will hold return value;
-
-	asm("pusha");
-	
-	// select syscall
-	asm("mov $61,%eax"); 
-
-	// pass params
-	asm("mov %0,%%edx"::"m"(file));
-	asm("mov %0,%%ecx"::"m"(ptr));
-	asm("mov %0,%%ebx"::"m"(len));
-
-	// interrupt
-	asm("int $0x80");         
-
-	// get return value	
-	asm("mov %%ebx, %0": "=b" (ebx));
+int execve(char *name, char **argv, char **env) 
+{
 
-	asm("popa");
-	
-	return ebx;
+    return syscall(64,name,argv,env);
 }
 
 
@@ -160,8 +125,3 @@ caddr_t sbrk(int incr)
 }
 //
 
-// helpers
-easywrite(char *c)
-{
-    write(1,c,strlen(c));
-}