Add system calls for working directory

kernel/include/scheduler.hpp

@@ -41,6 +41,9 @@ bool has_handle(size_t fd);
 void release_handle(size_t fd);
 const std::string& get_handle(size_t fd);
 
+const std::vector<std::string>& get_working_directory();
+void set_working_directory(const std::vector<std::string>& directory);
+
 } //end of namespace scheduler
 
 #endif

kernel/src/scheduler.cpp

@@ -41,6 +41,7 @@ struct process_control_t {
     size_t rounds;
     size_t sleep_timeout;
     std::vector<std::string> handles;
+    std::vector<std::string> working_directory;
 };
 
 //The Process Control Block
@@ -861,6 +862,14 @@ const std::string& scheduler::get_handle(size_t fd){
     return pcb[current_pid].handles[fd];
 }
 
+const std::vector<std::string>& scheduler::get_working_directory(){
+    return pcb[current_pid].working_directory;
+}
+
+void scheduler::set_working_directory(const std::vector<std::string>& directory){
+    pcb[current_pid].working_directory = directory;
+}
+
 //Provided for task_switch.s
 
 extern "C" {

kernel/src/system_calls.cpp

@@ -130,6 +130,32 @@ void sc_read(interrupt::syscall_regs* regs){
     regs->rax = vfs::read(fd, buffer, max);
 }
 
+void sc_pwd(interrupt::syscall_regs* regs){
+    auto wd = scheduler::get_working_directory();
+
+    std::string path;
+    path += '/';
+
+    for(auto& part : wd){
+        path += part;
+        path += '/';
+    }
+
+    auto buffer = reinterpret_cast<char*>(regs->rbx);
+    for(int i = 0; i < path.size(); ++i){
+        buffer[i] = path[i];
+    }
+    buffer[path.size()] = '\0';
+}
+
+void sc_cwd(interrupt::syscall_regs* regs){
+    auto p = reinterpret_cast<const char*>(regs->rbx);
+    std::string path(p);
+
+    auto cwd = std::split(path, '/');
+    scheduler::set_working_directory(cwd);
+}
+
 } //End of anonymous namespace
 
 void system_call_entry(interrupt::syscall_regs* regs){
@@ -208,6 +234,14 @@ void system_call_entry(interrupt::syscall_regs* regs){
             sc_read(regs);
             break;
 
+        case 304:
+            sc_pwd(regs);
+            break;
+
+        case 305:
+            sc_cwd(regs);
+            break;
+
         case 0x666:
             //TODO Do something with return code
             scheduler::kill_current_process();