310555003 lab5

Makefile

@@ -89,7 +89,7 @@ $(INITRAMFS_CPIO): $(INITRAMFS_FILES)
 	cd initramfs; find . | cpio -o -H newc > ../$(INITRAMFS_CPIO)
 
 qemu: all $(INITRAMFS_CPIO) $(RPI3_DTB)
-	qemu-system-aarch64 -M raspi3 -kernel $(BOOTLOADER_IMG) -display none \
+	qemu-system-aarch64 -M raspi3 -kernel $(BOOTLOADER_IMG) \
 						-initrd $(INITRAMFS_CPIO) \
 						-dtb $(RPI3_DTB) \
 						-chardev pty,id=pty0,logfile=pty.log,signal=off \

README.md

@@ -35,6 +35,18 @@ make image
 make qemu
 ```
 
+* You should either attach gdb to qemu, or just remove the arugments `-s -S` passed to qemu in the Makefile
+
+* Qemu will emulate the bootloader and you can then attach to the bootloader shell with:
+```
+sudo screen /dev/pts/<pts_idx>
+```
+
+* In the bootloader shell, you can use the command `load` to ask the bootloader to load the kernel image. After entering the `load` command, you can send the kernel image to the bootloader with the following command:
+```
+sudo ./tools/loadkernel.py /dev/pts/<pts_id> build/kernel8.img
+```
+
 ## How to burn it into pi3
 
 ```

include/kernel/cpio.h

@@ -11,12 +11,12 @@ void cpio_cat(char *cpio, char *filename);
 
 /*
  * Allocate a memory chunk and load the @filename program onto it. Then return
- * the address of the chunk. This memory chunk needs to be passed to kfree() 
- * manually.
+ * the address of the chunk by @output_data. @output_data needs to be passed 
+ * to kfree() manually.
  *
- * Return NULL if failed.
+ * Return output_data length, return 0 if no such file.
  */
-char *cpio_load_prog(char *cpio, char *filename);
+uint32 cpio_load_prog(char *cpio, const char *filename, char **output_data);
 
 void initramfs_init(void);
 

include/kernel/current.h

@@ -0,0 +1,20 @@
+#ifndef _CURRENT_H
+#define _CURRENT_H
+
+#include <utils.h>
+
+struct _task_struct;
+
+static inline struct _task_struct *get_current(void)
+{
+    return (struct _task_struct *)read_sysreg(tpidr_el1);
+}
+
+static inline void set_current(struct _task_struct *task)
+{
+    write_sysreg(tpidr_el1, task);
+}
+
+#define current get_current()
+
+#endif /* _CURRENT_H */

include/kernel/exec.h

@@ -1,8 +1,11 @@
 #ifndef _EXEC_H
 #define _EXEC_H
 
-// Change current EL to EL0 and execute the user program at @mem
-// Set user stack to @user_sp
-void exec_user_prog(char *mem, char *user_sp);
+// TODO: Add argv & envp
+void sched_new_user_prog(char *filename);
+
+void exit_user_prog(void);
+
+void exec_user_prog(void *entry, char *user_sp, char *kernel_sp);
 
 #endif /* _EXEC_H */

include/kernel/irq.h

@@ -8,7 +8,10 @@ void irq_init();
 /*
  * On success, 0 is returned
  */
-int irq_add_tasks(void (*task)(void *), void *args, uint32 prio);
+int irq_run_task(void (*task)(void *),
+                 void *args,
+                 void (*fini)(void),
+                 uint32 prio);
 
 void irq_handler();
 void exception_default_handler(uint32 n);

include/kernel/kthread.h

@@ -0,0 +1,15 @@
+#ifndef _KTHREAD_H
+#define _KTHREAD_H
+
+#include <task.h>
+
+void kthread_init(void);
+
+void kthread_create(void (*start)(void));
+void kthread_fini(void);
+
+void kthread_add_wait_queue(task_struct *task);
+
+void kthread_kill_zombies(void);
+
+#endif /* _KTHREAD_H */

include/kernel/mini_uart.h

@@ -6,15 +6,15 @@
 uint32 uart_recvline(char *buff, int maxlen);
 void uart_init(void);
 char uart_recv(void);
+void uart_recvn(char *buff, int n);
 uint32 uart_recv_uint(void);
 void uart_send(char c);
-void uart_sendn(char *str, int n);
-void uart_printf(char *fmt, ...);
+void uart_sendn(const char *str, int n);
+void uart_printf(const char *fmt, ...);
 
-void uart_sync_printf(char *fmt, ...);
+void uart_sync_printf(const char *fmt, ...);
 
-void uart_irq_check(void);
-void uart_irq_handler(void);
+int uart_irq_check(void);
 
 /* Switch asynchronous/synchronous mode for uart RW */
 int uart_switch_mode(void);

include/kernel/mode_switch.h

@@ -0,0 +1,8 @@
+#ifndef _MODE_SWITCH_H
+#define _MODE_SWITCH_H
+
+#include <trapframe.h>
+
+void exit_to_user_mode(trapframe regs);
+
+#endif /* _MODE_SWITCH_H */

include/kernel/preempt.h

@@ -0,0 +1,7 @@
+#ifndef _PREEMPT_H
+#define _PREEMPT_H
+
+void preempt_disable(void);
+void preempt_enable(void);
+
+#endif /* _PREEMPT_H */

include/kernel/sched.h

@@ -0,0 +1,18 @@
+#ifndef _SCHED_H
+#define _SCHED_H
+
+#include <task.h>
+
+void switch_to(task_struct *from, task_struct *to);
+
+void scheduler_init(void);
+
+void schedule(void);
+
+void schedule_tick(void);
+
+void sched_add_task(task_struct *task);
+
+void sched_del_task(task_struct *task);
+
+#endif /* _SCHED_H */

include/kernel/signal.h

@@ -0,0 +1,89 @@
+#ifndef _SIGNAL_H
+#define _SIGNAL_H
+
+#include <types.h>
+#include <list.h>
+#include <trapframe.h>
+
+// https://man7.org/linux/man-pages/man7/signal.7.html
+// 0 means no signal
+#define SIGHUP      1
+#define SIGINT      2
+#define SIGQUIT     3
+#define SIGILL      4
+#define SIGTRAP     5
+#define SIGABRT     6
+#define SIGIOT      6
+#define SIGBUS      7
+#define SIGFPE      8
+#define SIGKILL     9
+#define SIGUSR1     10
+#define SIGSEGV     11
+#define SIGUSR2     12
+#define SIGPIPE     13
+#define SIGALRM     14
+#define SIGTERM     15
+#define SIGSTKFLT   16
+#define SIGCHLD     17
+#define SIGCONT     18
+#define SIGSTOP     19
+#define SIGTSTP     20
+#define SIGTTIN     21
+#define SIGTTOU     22
+#define SIGURG      23
+#define SIGXCPU     24
+#define SIGXFSZ     25
+#define SIGVTALRM   26
+#define SIGPROF     27
+#define SIGWINCH    28
+#define SIGIO       29
+#define SIGPOLL     29
+#define SIGPWR      30
+#define SIGSYS      31
+#define SIGUNUSED   31
+
+#define NSIG		32
+
+struct signal_head_t {
+    /* Link signal_t */
+    struct list_head list;
+};
+
+struct signal_t {
+    struct list_head list;
+    uint32 signum;
+};
+
+typedef void (*sighandler_t)(int);
+
+struct sigaction_t {
+    sighandler_t sighand;
+
+    /* flags */
+    uint32 kernel_hand;
+};
+
+struct sighand_t {
+    // 0-th sigaction_t is not used
+    struct sigaction_t sigactions[NSIG];
+};
+
+struct signal_head_t *signal_head_create(void);
+void signal_head_free(struct signal_head_t *head);
+void signal_head_reset(struct signal_head_t *head);
+
+void handle_signal(trapframe *_);
+
+struct sighand_t *sighand_create(void);
+void sighand_free(struct sighand_t *sighand);
+void sighand_reset(struct sighand_t *sighand);
+
+/* Copy current signal handler to @sighand */
+void sighand_copy(struct sighand_t *sighand, void *addrbase);
+
+/* syscalls */
+void syscall_signal(trapframe *_, uint32 signal, void (*handler)(int));
+void syscall_kill(trapframe *_, int pid, int signal);
+void syscall_sigreturn(trapframe *_);
+
+#endif /* _SIGNAL_H */

include/kernel/syscall.h

@@ -2,9 +2,10 @@
 #define _SYSCALL_H
 
 #include <types.h>
+#include <trapframe.h>
 
 // @syn: syndrome information for an synchronous exception
 // One should pass esr_el1 register value to @syn
-void syscall_handler(uint32 syn);
+void syscall_handler(trapframe regs, uint32 syn);
 
 #endif /* _SYSCALL_H */

include/kernel/task.h

@@ -0,0 +1,75 @@
+#ifndef _TASK_H
+#define _TASK_H
+
+#include <types.h>
+#include <list.h>
+
+#define STACK_SIZE (2 * PAGE_SIZE)
+
+/* Task status */
+#define TASK_NEW        0
+#define TASK_RUNNING    1
+#define TASK_DEAD       2
+
+/* Define in include/kernel/signal.h */
+struct signal_head_t;
+struct sighand_t;
+
+struct pt_regs {
+    void *x19;
+    void *x20;
+    void *x21;
+    void *x22;
+    void *x23;
+    void *x24;
+    void *x25;
+    void *x26;
+    void *x27;
+    void *x28;
+    void *fp;
+    void *lr;
+    void *sp;
+};
+
+typedef struct _task_struct {
+    /* This must be the first element */
+    struct pt_regs regs;
+    void *kernel_stack;
+    void *user_stack;
+    /* TODO: Update to address_space */
+    void *data;
+    uint32 datalen;
+    /* @list is used by run_queue / wait_queue */
+    struct list_head list;
+    /* @task_list links all tasks */
+    struct list_head task_list;
+    uint16 status;
+    uint16 need_resched:1;
+    uint32 tid;
+    uint32 preempt;
+    /* Signal */
+    struct signal_head_t *signal;
+    struct sighand_t *sighand;
+} task_struct;
+
+#define SAVE_REGS(task) \
+    asm volatile (                          \
+        "stp x19, x20, [%x0, 16 * 0]\n"     \
+        "stp x21, x22, [%x0, 16 * 1]\n"     \
+        "stp x23, x24, [%x0, 16 * 2]\n"     \
+        "stp x25, x26, [%x0, 16 * 3]\n"     \
+        "stp x27, x28, [%x0, 16 * 4]\n"     \
+        "stp fp, lr, [%x0, 16 * 5]\n"       \
+        "mov x9, sp\n"                      \
+        "str x9, [%x0, 16 * 6]\n"           \
+        : : "r" (&task->regs)               \
+    );
+
+void task_init(void);
+
+task_struct *task_create(void);
+void task_free(task_struct *task);
+
+task_struct *task_get_by_tid(uint32 tid);
+
+#endif /* _TASK_H */

include/kernel/timer.h

@@ -4,11 +4,13 @@
 #include <types.h>
 
 void timer_init();
-void timer_irq_check();
-void timer_irq_handler();
+int timer_irq_check();
 void timer_switch_info();
 
 /* Call @proc(@args) after @after seconds. */
-void timer_add_proc(void (*proc)(void *), void *args, uint32 after);
+void timer_add_proc_after(void (*proc)(void *), void *args, uint32 after);
+
+/* Call @proc(@args) after 1/@freq second. */
+void timer_add_proc_freq(void (*proc)(void *), void *args, uint32 freq);
 
 #endif /* _TIMER_H */