Stash pop

Makefile

@@ -18,7 +18,7 @@ AR = $(shell cat psinfo/$(PLAT)/ar.txt)
 NASM = $(shell cat psinfo/$(PLAT)/nasm.txt)
 EMU = $(shell cat psinfo/$(PLAT)/emu.txt)
 CFLAGS =  -Isysroot/usr/include -Wextra -Wall -Wno-unused-parameter -g -ffreestanding
-QFLAGS =  -hda ext2.img -m 2G -boot d -cdrom os.iso -serial file:serout #-chardev socket,id=s1,port=3000,host=localhost -serial chardev:s1
+QFLAGS =  -m 2G -boot d -cdrom os.iso -serial file:serout #-chardev socket,id=s1,port=3000,host=localhost -serial chardev:s1
 CWD = $(shell pwd)
 
 .PHONY: sysroot
@@ -31,19 +31,29 @@ run: os.iso
 	@$(EMU) $(QFLAGS) &
 	tail -f serout
 
+run_nobuild:
+	rm -f serout
+	touch serout
+	@$(EMU) $(QFLAGS) &
+	tail -f serout
+
 debug: os.iso kernel/kernel.elf
 	@$(EMU) -s $(QFLAGS) &
 	gdb
 	#gdbgui -g i386-elf-gdb --project $(CWD)
 
-os.iso: kernel/kernel.elf init vfs devfs vga_drv initrd_drv tar_fs pci sysroot/usr/share/man # vfs devfs initrd vga_drv initrd_drv pci
+os.iso: kernel/kernel.elf init vfs devfs vga_drv initrd_drv tar_fs pci ps2 sysroot/usr/share/man # vfs devfs initrd vga_drv initrd_drv pci
 	@cp kernel/kernel.elf sysroot/boot
 	@cd initrd; tar -f ../sysroot/boot/initrd.tar -c *
-	@grub-mkrescue -o $@ sysroot >/dev/null 2>/dev/null
+	@grub-mkrescue -o $@ sysroot 
 
 crts: kernel/crt0.o
 	@cp $^ sysroot/usr/lib
 
+ps2: crts libc
+	@cd $@ && make
+	@cp $@/$@ initrd/$@
+
 init: crts libc
 	@cd $@ && make
 	@cp $@/$@ initrd/$@
@@ -107,3 +117,8 @@ clean:
 doc: $(C_SOURCES) $(C_HEADERS)
 	@doxygen kernel/Doxyfile > /dev/null
 	@doxygen libc/Doxyfile > /dev/null
+
+install:
+	@echo Path to flash drive?; \
+	read drive; \
+	echo $$(drive);

init/main.c

@@ -123,5 +123,7 @@ int main() {
     serial_print("Could not open the VGA device file!\n");
     exit(1);
   }
-  posix_spawn(NULL,"/initrd/pci",NULL,NULL,NULL,NULL);
+  posix_spawn(NULL,"/initrd/ps2",NULL,NULL,NULL,NULL);
+  // posix_spawn(NULL,"/initrd/pci",NULL,NULL,NULL,NULL);
+  for(;;);
 }

kernel/Doxyfile

@@ -5,7 +5,7 @@ TYPEDEF_HIDES_STRUCT   = YES
 EXTRACT_STATIC         = YES
 WARN_NO_PARAMDOC       = YES
 WARN_AS_ERROR          = YES
-INPUT                  = /Users/peterterpstra/Desktop/projects/os/kernel
+INPUT                  = ./kernel
 RECURSIVE              = YES
 EXCLUDE                = kernel/cpu/x86_64
 HTML_DYNAMIC_SECTIONS  = YES

kernel/cpu/i386/idt.c

@@ -34,7 +34,7 @@ typedef struct {
 
 #define IDT_ENTRIES 256 //!< Number of entries in the IDT
 
-static idt_gate_t idt[IDT_ENTRIES]; //!< The IDT
+idt_gate_t idt[IDT_ENTRIES] __attribute__((aligned(4096))); //!< The IDT
 static idt_register_t idt_reg; //!< The value to load into the IDTR
 
 #define LOW_16(address) (uint16_t)((address) & 0xFFFF) //!< Macro to get the low 16 bits of an address

kernel/cpu/i386/isr.c

@@ -6,7 +6,6 @@
 #include "../../vga_err.h"
 #include "../../address_spaces.h"
 #include "../halt.h"
-#include "../isr.h"
 #include "../paging.h"
 #include "../serial.h"
 //#include "../../rpc.h"
@@ -20,8 +19,15 @@
 #include <sys/syscalls.h>
 #include <sys/types.h>
 
-void irq_handler(registers_t* r);
+/** 
-static isr_t irq_handlers[16]; //!< Handlers for the PIC interrupts
+ * Represents a registeted interrupt handler
+*/
+typedef struct {
+  pid_t pid; //!< The PID thast registered the handler, or 0 if it it a kernel handler
+  void* handler; //!< The address of the handler
+} isr_handler_info;
+
+static isr_handler_info irq_handlers[16]={0}; //!< Handlers for the PIC interrupts
 
 void isr_install() {
     idt_set_gate(0,(uint32_t)isr0);
@@ -203,7 +209,7 @@ void isr_handler(registers_t* r) {
     case 80:
       switch (r->eax) {
       case SYSCALL_CREATEPROC:
-        tasking_create_task((void*)r->ebx,(void*)r->ecx,0,(void*)r->edx,(void*)r->esi,0);
+        tasking_create_task((void*)r->ebx,(void*)r->ecx,0,(void*)r->edx,(void*)r->esi,0,0);
         break;
       case SYSCALL_YIELD:
         tasking_yield();
@@ -259,7 +265,7 @@ void isr_handler(registers_t* r) {
         memcpy((char*)r->ebx,initrd,initrd_sz);
         break;
       case SYSCALL_NEW_THREAD: {
-        uint32_t tid=tasking_new_thread((void*)r->ebx,tasking_get_PID(),(void*)r->edx);
+        uint32_t tid=tasking_new_thread((void*)r->ebx,tasking_get_PID(),(void*)r->edx,0);
         if ((uint32_t*)r->ecx!=NULL) {
           *((uint32_t*)r->ecx)=tid;
         }
@@ -289,7 +295,8 @@ void isr_handler(registers_t* r) {
       case SYSCALL_RPC_IS_INIT:
         r->ecx=kernel_rpc_is_init((pid_t)r->ebx);
         break;
-      default:
+      case SYSCALL_REGISTER_IRQ_HANDLER:
+        isr_register_handler((int)r->ebx,tasking_get_PID(),(void*)r->ecx);
         break;
       }
       break;
@@ -298,11 +305,12 @@ void isr_handler(registers_t* r) {
 }
 
 
-void isr_register_handler(int n,isr_t handler) {
+void isr_register_handler(int n,pid_t pid,void* handler) {
     if (n>16) {
       return;
     }
-    irq_handlers[n] = handler;
+    irq_handlers[n].pid = pid;
+    irq_handlers[n].handler = handler;
 }
 
 /**
@@ -315,12 +323,12 @@ void irq_handler(registers_t* r) {
   if (r->int_no >= 40) port_byte_out(0xA0,0x20); /* slave */
   port_byte_out(0x20,0x20); /* master */
   /* Handle the interrupt in a more modular way */
-  if (irq_handlers[r->int_no-32] != NULL) {
+  if (irq_handlers[r->int_no-32].handler!=NULL) {
-    isr_t handler = irq_handlers[r->int_no-32];
+    isr_handler_info info = irq_handlers[r->int_no-32];
-    if((uint32_t)handler<32768) {
+    if(info.pid==0) {
-      kernel_rpc_call((pid_t)handler,"irq_handler",NULL,NULL);
+      ((isr_t)info.handler)(r);
     } else {
-      handler(r);
+      tasking_new_thread(info.handler,info.pid,(void*)(r->int_no-32),1);
     }
   }
 }

kernel/cpu/i386/isr.h

@@ -6,6 +6,7 @@
 #define ISR_H
 
 #include <stdint.h>
+#include <sys/types.h>
 
 /** 
  * Saved state of the CPU when an interrupt occurs
@@ -38,9 +39,12 @@ void isr_install();
 
 /**
  * Register an IRQ handler
- * \param n the IRQ to register a handler for
+ * 
- * \param handler the handler to register
+ * If the PID is 0, the handler will be called directly, otherwise a thread will be made in the PID starting at the handler's address.
+ * \param n The IRQ to register a handler for
+ * \param pid The PID that will handle the interrupt. 
+ * \param handler The address of the handler.
 */
-void isr_register_handler(int n,isr_t handler);
+void isr_register_handler(int n,pid_t pid,void* handler);
 
 #endif

kernel/cpu/i386/paging.c

@@ -190,6 +190,18 @@ void unmap_pages(void* start_virt,int num_pages,int free_phys) {
   }
 }
 
+extern int idt;
+
+/**
+ * Makes the IDT readonly
+*/
+void paging_readonly_idt() {
+  void* idt_addr=&idt;
+  void* idt_phys=virt_to_phys(idt_addr);
+  map_pages(idt_addr,idt_phys,1,0,0);
+  invl_page(idt_addr);
+}
+
 void paging_init() {
   for (size_t i=0;i<NUM_KERN_FRAMES;i++) {
     pg_struct_entry* entry=&kern_page_tables[i];

kernel/cpu/i386/tasking_helpers.asm

@@ -49,7 +49,7 @@ switch_to_thread_asm:
 
 global task_init
 
-; Switch to usermode, given a usermode stack and EIP to switch to
+; Switch to usermode and enable interrupts, given a usermode stack and EIP to switch to
 
 task_init:
   pop ecx ; ecx = user ESP
@@ -69,6 +69,26 @@ task_init:
   push ebx ; push user EIP
   iret
 
+
+global task_init_no_int
+
+; Switch to usermode, given a usermode stack and EIP to switch to
+
+task_init_no_int:
+  pop ecx ; ecx = user ESP
+  pop ebx ; ebx = user EIP
+  mov ax, 0x23 ; Load data segment selectors with the usermode data segment
+  mov ds, ax
+  mov es, ax
+  mov fs, ax
+  mov gs, ax
+  push 0x23 ; Push SS
+  push ecx ; push user ESP
+  pushf ; push flagstrew
+  push 0x1B ; push CS
+  push ebx ; push user EIP
+  iret
+
 global wait_for_unblocked_thread_asm
 
 wait_for_unblocked_thread_asm:

kernel/cpu/i386/tasking_helpers_c.c

@@ -56,7 +56,7 @@ static int new_kstack() {
   return num;
 }
 
-void setup_kstack(Thread* thread,void* param1,void* param2,char kmode,void* eip) {
+void setup_kstack(Thread* thread,void* param1,void* param2,char kmode,void* eip,char is_irq_handler) {
   size_t kstack_num=new_kstack();
   if (kmode) {
     size_t top_idx=(1024*(kstack_num+1));
@@ -74,7 +74,11 @@ void setup_kstack(Thread* thread,void* param1,void* param2,char kmode,void* eip)
       user_stack[0]=param2;
       user_stack[1]=param1;
     });
+    if (is_irq_handler) {
+      kstacks[top_idx-3]=(void*)task_init_no_int;
+    } else {
     kstacks[top_idx-3]=(void*)task_init;
+    }
     kstacks[top_idx-2]=(void*)user_stack;
     kstacks[top_idx-1]=(void*)eip;
   }

kernel/cpu/isr.h

@@ -6,6 +6,7 @@
 #define ISR_H
 
 #include <stdint.h>
+#include <sys/types.h>
 
 /** 
  * Saved state of the CPU when an interrupt occurs
@@ -38,9 +39,12 @@ void isr_install();
 
 /**
  * Register an IRQ handler
- * \param n the IRQ to register a handler for
+ * 
- * \param handler the handler to register
+ * If the PID is 0, the handler will be called directly, otherwise a thread will be made in the PID starting at the handler's address.
+ * \param n The IRQ to register a handler for
+ * \param pid The PID that will handle the interrupt. 
+ * \param handler The address of the handler.
 */
-void isr_register_handler(int n,isr_t handler);
+void isr_register_handler(int n,pid_t pid,void* handler);
 
 #endif

kernel/cpu/tasking_helpers.h

@@ -18,6 +18,11 @@ void switch_to_thread_asm(Thread* thread);
 */
 void task_init();
 
+/**
+ * Initializes a usermode task without interrupts enabled
+*/
+void task_init_no_int();
+
 /**
  * An assembly helper for waiting for an unblocked thread
  * Starts interrupts, halts, then clears interrupts.
@@ -31,8 +36,9 @@ void wait_for_unblocked_thread_asm();
  * \param param2 The thread's start function second parameter
  * \param kmode Whether the thread is a kernel mode thread
  * \param eip The start address of the thread
+ * \param is_irq_handler Whether the kernel stack is for an interrupt handler thread
 */
-void setup_kstack(Thread* thread,void* param1,void* param2,char kmode,void* eip);
+void setup_kstack(Thread* thread,void* param1,void* param2,char kmode,void* eip,char is_irq_handler);
 
 /**
  * Frees a kernel stack so it can be used again

kernel/kmalloc.c

@@ -6,6 +6,8 @@
 #include <math.h>
 #include <stdlib.h>
 #include <string.h>
+#include "cpu/serial.h"
+#include "cpu/halt.h"
 
 #define KMALLOC_BMAP_SZ (((KMALLOC_SZ*1024)/4)/8) //!< The size of the kmalloc bitmap
 
@@ -85,6 +87,8 @@ void* kmalloc(size_t size) {
     }
   }
   if (remaining_blks!=0) {
+    serial_printf("Kmalloc fail!\n");
+    halt();
     return NULL;
   }
   for (size_t i=0;i<num_4b_grps;i++) {

kernel/pmem.c

@@ -123,6 +123,8 @@ void* pmem_alloc(int num_pages) {
     }
   }
   if (remaining_blks!=0) {
+    serial_printf("Out of memory! Halting!\n");
+    halt();
     return NULL;
   }
   for (int i=0;i<num_pages;i++) {

kernel/rpc.c

@@ -94,7 +94,7 @@ void* kernel_rpc_call(pid_t pid,char* name,void* buf,size_t size) {
       map_pages(virtaddr,physaddr,(size/PAGE_SZ)+1,1,1);
     });
   }
-  pid_t tid=tasking_new_thread(func->code,pid,virtaddr);
+  pid_t tid=tasking_new_thread(func->code,pid,virtaddr,0);
   tasking_set_rpc_calling_thread(pid,tid);
   // Block the thread and wait for an unblock from rpc_return
   tasking_block(THREAD_WAITING_FOR_RPC);

kernel/tasking.c

@@ -90,7 +90,7 @@ void schedule_thread(Thread* thread) {
   }
 }
 
-void tasking_create_task(void* eip,void* address_space,char kmode,void* param1,void* param2,char isThread) {
+void tasking_create_task(void* eip,void* address_space,char kmode,void* param1,void* param2,char isThread,char is_irq_handler) {
   if (next_pid>MAX_PROCS && !isThread) {
     serial_printf("Failed to create a process, as 32k processes have been created already.\n");
     halt(); //Cannot ever create more than 32k processes, as I don't currently reuse PIDs.
@@ -118,9 +118,19 @@ void tasking_create_task(void* eip,void* address_space,char kmode,void* param1,v
     num_procs++;
   }
   proc->first_thread=thread;
-  setup_kstack(thread,param1,param2,kmode,eip);
+  setup_kstack(thread,param1,param2,kmode,eip,is_irq_handler);
   schedule_thread(thread);
-  // serial_printf("Created thread with PID %d and TID %d.\n",proc->pid,thread->tid);
+  serial_printf("Created thread with PID %d and TID %d.\n",proc->pid,thread->tid);
+  serial_printf("Structure values:\n");
+  serial_printf("kernel_esp=%x\n",thread->kernel_esp);
+  serial_printf("kernel_esp_top=%x\n",thread->kernel_esp_top);
+  serial_printf("address_space=%x\n",thread->address_space);
+  serial_printf("tid=%d\n",thread->tid);
+  serial_printf("state=%d\n",thread->state);
+  serial_printf("next_thread_in_process=%x\n",thread->next_thread_in_process);
+  serial_printf("next_ready_to_run=%x\n",thread->next_ready_to_run);
+  serial_printf("prev_ready_to_run=%x\n",thread->prev_ready_to_run);
+  serial_printf("process=%x\n",thread->process);
 }
 
 void tasking_init() {
@@ -128,7 +138,7 @@ void tasking_init() {
     memset(&processes[i],0,sizeof(Process));
   }
   
-  tasking_create_task(NULL,get_address_space(),1,NULL,NULL,0);
+  tasking_create_task(NULL,get_address_space(),1,NULL,NULL,0,0);
 }
 
 char tasking_is_privleged() {
@@ -147,8 +157,8 @@ int* tasking_get_errno_address() {
   return &current_thread->errno;
 }
 
-pid_t tasking_new_thread(void* start,pid_t pid,void* param) {
+pid_t tasking_new_thread(void* start,pid_t pid,void* param,char is_irq_handler) {
-  tasking_create_task(start,NULL,0,param,(void*)pid,1);
+  tasking_create_task(start,NULL,0,param,(void*)pid,1,is_irq_handler);
   return processes[pid].first_thread->tid;
 }
 
@@ -389,7 +399,6 @@ void* tasking_get_rpc_ret_buf() {
 
 void tasking_thread_exit() {
   tasking_block(THREAD_EXITED);
-  free_kstack(current_thread->kernel_esp_top);
 }
 
 char tasking_check_proc_exists(pid_t pid) {

kernel/tasking.h

@@ -57,7 +57,7 @@ typedef struct Thread {
   pid_t rpc_calling_pid; //!< The PID of the thread that called this RPC (only used for RPC handler threads)
   pid_t rpc_calling_tid; //!< The TID of the thread that called this RPC (only used for RPC handler threads)
   void* rpc_ret_buf; //!< The return buffer of the RPC call that the thread made
-} Thread;
+} __attribute__((packed)) Thread;
 
 extern Thread* current_thread;
 
@@ -69,8 +69,9 @@ extern Thread* current_thread;
  * \param param1 The thread's start function first parameter
  * \param param2 The thread's start function second parameter
  * \param isThread Whether we are creating a new process or a thread in a process. If we are creating a theead, param2_arg becomes the PID for the newly created thread.
+ * \param is_irq_handler Whether the new task is an irq handler task
 */
-void tasking_create_task(void* eip,void* address_space,char kmode,void* param1,void* param2,char isThread);
+void tasking_create_task(void* eip,void* address_space,char kmode,void* param1,void* param2,char isThread,char is_irq_handler);
 /**
  * Initialize tasking
 */
@@ -100,9 +101,10 @@ int* tasking_get_errno_address();
  * \param start The start address of the task
  * \param pid The PID that gets the new thread
  * \param param The thread's start function parameter
+ * \param is_irq_handler Whether the new thread is an irq handler thread
  * \return the TID of the thread
 */
-pid_t tasking_new_thread(void* start,pid_t pid,void* param);
+pid_t tasking_new_thread(void* start,pid_t pid,void* param,char is_irq_handler);
 
 /**
  * Terminate the current thread

kernel/timer/pit/timer.c

@@ -19,7 +19,7 @@ void timer_init(int freq) {
   } else {
     serial_printf("Setting PIT to %dHz using divisor of %d\n",freq,div);
   }
-  isr_register_handler(0,timer_handler);
+  isr_register_handler(0,0,timer_handler);
   port_byte_out(0x43,0b00110110); // Set timer 0 to lobyte/hibyte access, and mode 3 (square wave generator)
   port_byte_out(0x40,div&0xFF); 
   port_byte_out(0x40,(div>>8)&0xFF);

libc/Doxyfile

@@ -5,7 +5,7 @@ TYPEDEF_HIDES_STRUCT   = YES
 EXTRACT_STATIC         = YES
 WARN_NO_PARAMDOC       = YES
 WARN_AS_ERROR          = YES
-INPUT                  = /Users/peterterpstra/Desktop/projects/os/libc
+INPUT                  = ./libc
 RECURSIVE              = YES
 EXCLUDE                = libc/elf.h libc/grub/multiboot2.h
 HTML_DYNAMIC_SECTIONS  = YES

libc/sys/syscalls.h

@@ -28,5 +28,6 @@
 #define SYSCALL_RPC_RET 18
 #define SYSCALL_RPC_MARK_AS_INIT 21
 #define SYSCALL_RPC_IS_INIT 22
+#define SYSCALL_REGISTER_IRQ_HANDLER 23
 
 #endif