Implement syscalls, hello world from userspace

kernel/proc/proc.c

@@ -15,12 +15,6 @@
 
 #define PROC_REAPER_FREQ 30
 
-#define PROC_DIE() \
-  do { \
-    proc_killself(); \
-    for(;;); \
-  } while(0)
-
 uint64_t pids = 0;
 uint64_t sched_ticks = 0;
 
@@ -161,8 +155,16 @@ void proc_register(Proc *proc) {
 }
 
 Proc *proc_nextready(void) {
-  Proc *next = PROCS.current->next;
-  Proc *proc = next == NULL ? PROCS.procs : next;
+  Proc *proc = PROCS.current->next;
+  for (;;) {
+    if (proc == NULL) {
+      proc = PROCS.procs;
+    }
+    if (proc->state != PROC_ZOMBIE) {
+      return proc;
+    }
+    proc = proc->next;
+  }
   return proc;
 }
 
@@ -183,7 +185,7 @@ void proc_reaper(void) {
         while (vashead) {
           VasRange *tmp = vashead;
           vashead = vashead->next;
-          hal_vmm_unmap_range(zombie->platformdata.cr3, tmp->virtstart, tmp->physstart, tmp->size);
+          hal_vmm_unmap_range(VIRT(zombie->platformdata.cr3), tmp->virtstart, tmp->physstart, tmp->size);
           // first pmm mapping is for the elf itself
           if (i == 0) {
             pmm_free((uintptr_t)tmp->physstart, tmp->size / HAL_PAGE_SIZE);
@@ -218,6 +220,7 @@ void proc_sched(void *cpustate) {
   PROCS.current->state = PROC_RUNNING;
 
   hal_cpu_wrmsr(HAL_CPU_FSBASE, PROCS.current->platformdata.fsbase);
+  HAL_CPUS[0].syscall_kstack = VIRT(PROCS.current->platformdata.kstack);
   hal_switchproc(&PROCS.current->platformdata.trapframe, (void *)PROCS.current->platformdata.cr3);
 }
 
@@ -239,11 +242,12 @@ void proc_idle(void) {
 }
 
 void proc_status(void) {
+  static const char *statuses[] = {"ready", "running", "zombie", "waiting"};
   for (;;) {
     spinlock_acquire(&PROCS.spinlock);
     Proc *head = PROCS.procs;
     while (head) {
-      kprintf("%s %s\n", head->kern ? "kern" : "user", head->name);
+      kprintf("%s %s %s\n", head->kern ? "kern" : "user", statuses[head->state], head->name);
       head = head->next;
     }
     kprintf("\n\n");