Clean up and organize boot logging.

Author: cstack

data_structures/page_table.c

@@ -162,17 +162,17 @@ page_directory_t initialize_page_directory() {
   return pd;
 }
 
-void print_page_directory(FILE stream, page_directory_t pd) {
+uint32_t num_present_pages(page_directory_t pd) {
+  uint32_t num = 0;
   for (int i = 0; i < 1024; i++) {
     uint32_t entry = pd[i];
     bool present = entry & 0x1;
 
     if (present) {
-      fprintf(stream, "page directory entry ");
-      print_uint32(stream, i);
-      fprintf(stream, " is present.\n");
+      num += 1;
     }
   }
+  return num;
 }
 
 uint32_t round_up_to_nearest_page_start(uint32_t address) {

data_structures/page_table.h

@@ -17,7 +17,7 @@ typedef uint32_t * page_table_t;
 
 uint32_t initialize_page_allocator(struct kernel_memory_descriptor_t kernel_memory, multiboot_info_t* mbinfo);
 page_directory_t initialize_page_directory();
+uint32_t num_present_pages(page_directory_t pd);
 void page_in(void* virtual_address);
-void print_page_directory(FILE stream, page_directory_t pd);
 
 #endif /* INCLUDE_PAGE_TABLE_H */

interrupts.c

@@ -10,13 +10,15 @@
 #define INT_KEYBOARD 0x00000009
 #define INT_GENERAL_PROTECTION_FAULT 0x0000000D
 #define INT_PAGE_FAULT 0x0000000E
+#define INT_SOFTWARE 0x00000031
 
-void interrupt_handler(struct cpu_state cpu, uint32_t interrupt_number, uint32_t error_code, uint32_t eip) {
-  log("\n!!! Interrupt\n");
-  log("interrupt_number: ");
-  print_uint32(LOG, interrupt_number);
-  log("\n");
+void log_interrupt_details(char* int_name, uint32_t error_code, uint32_t eip, struct cpu_state* cpu) {
+  if(cpu->ebp){}
+  log("--------------------\n");
 
+  log("Interrupt : ");
+  log(int_name);
+  log("\n");
   log("error_code: ");
   print_uint32(LOG, error_code);
   log("\n");
@@ -27,9 +29,9 @@ void interrupt_handler(struct cpu_state cpu, uint32_t interrupt_number, uint32_t
   char * symbol_name = address_to_symbol_name(eip);
   fprintf(LOG, symbol_name);
   log("\n");
-  uint32_t ebp = cpu.ebp;
+  uint32_t ebp = cpu->ebp;
   while (ebp & 0xC0100000) {
-    uint32_t eip = ((uint32_t*) ebp)[1];
+    eip = ((uint32_t*) ebp)[1];
     print_uint32(LOG, eip);
     log(" : ");
     char * symbol_name = address_to_symbol_name(eip);
@@ -38,8 +40,11 @@ void interrupt_handler(struct cpu_state cpu, uint32_t interrupt_number, uint32_t
 
     ebp = *((uint32_t*)ebp);
   }
-  log("\n");
 
+  log("--------------------\n");
+}
+
+void interrupt_handler(struct cpu_state cpu, uint32_t interrupt_number, uint32_t error_code, uint32_t eip) {
   switch(interrupt_number) {
     case(INT_KEYBOARD):
       keyboard_interrupt_handler();
@@ -77,6 +82,10 @@ void interrupt_handler(struct cpu_state cpu, uint32_t interrupt_number, uint32_t
       }
       break;
 
+    case(INT_SOFTWARE):
+      log_interrupt_details("INT_SOFTWARE", error_code, eip, &cpu);
+      break;
+
     default:
       log("ERROR: Unabled to handle interrupt: ");
       print_uint32(LOG, interrupt_number);

kmain.c

@@ -39,13 +39,9 @@ static char *welcome_string = ""
 "                                                                                "
 "";
 
-void trigger_page_fault() {
-  uint32_t * unmapped_address = (uint32_t *) 0x400000; // 4 MB
-  log("Trying to access address ");
-  print_uint32(LOG, (uint32_t) unmapped_address);
-  log(":\n");
-  print_uint8(LOG, *unmapped_address);
-  log("\n. Successfully accessed.\n");
+uint32_t trigger_page_fault() {
+  uint32_t* unmapped_address = (uint32_t *) 0x400000; // 4 MB
+  return *unmapped_address;
 }
 
 struct test_struct_t {
@@ -63,68 +59,83 @@ void kmain(struct kernel_memory_descriptor_t kernel_memory, uint32_t ebx) {
   printf(welcome_string);
 
   serial_init();
-  log("\n--------------------\ncstackOS is booting!\n--------------------\n\nInitialized serial port.\n");
+  log("\n--------------------\ncstackOS is booting!\n--------------------\n\n");
 
+  #ifdef DEBUG
   log("\nMultiboot info passed to kernel from GRUB:\n");
   print_multiboot_info(LOG, mbinfo);
   log("\n");
+  #endif
 
+  log("- Initializing symbol table...\n");
   if (load_symbol_table(get_elf_section(mbinfo, ".symtab"), get_elf_section(mbinfo, ".strtab"))) {
-    log("Initialized symbol table.\n");
+    log("  - done\n");
   } else {
     log("ERROR: Could not initialize symbol table.\n");
+    while(1){}
   }
 
+  log("- Initializing global descriptor table...\n");
   initialize_gdt();
-  log("Loaded global descriptor table.\n");
+  log("  - done\n");
 
+  log("- Initializing interrupt descriptor table...\n");
   initialize_idt();
-  log("Loaded interrupt descriptor table.\n");
+  log("  - done\n");
 
-  log("Issuing test interrupt.\n");
+  log("- Issuing test interrupt...\n");
   interrupt(49);
-  log("Returned from test interrupt()\n");
+  log("  - done\n");
 
+  log("- Initializing programable interrupt controller...\n");
   pic_init();
-  log("Initialized PIC\n");
+  log("  - done\n");
 
+  log("- Initializing page allocator...\n");
   uint32_t free_pages = initialize_page_allocator(kernel_memory, mbinfo);
-  log("Initialized page allocator.\n");
+  log("  - done\n");
+  log("  - ");
   print_uint32(LOG, free_pages);
   log(" free pages (");
   print_uint32(LOG, free_pages / 256);
   log(" MB)\n");
 
+  log("- Initializing page directory...\n");
   page_directory_t pd = initialize_page_directory();
-  log("Initialized page directory.\n");
-  log("Address of page directory: ");
+  log("  - done\n");
+  log("  - Address of page directory: ");
   print_uint32(LOG, (uint32_t) pd);
   log("\n");
+  uint32_t num_pages = num_present_pages(pd);
+  log("  - ");
+  print_uint32(LOG, num_pages);
+  log(" present pages\n");
+
+  log("- Triggering a page fault...\n");
+  uint32_t value = trigger_page_fault();
+  log("  - done\n");
+  log("  - value at unmapped address was ");
+  print_uint32(LOG, value);
+  log("\n");
 
-  print_page_directory(LOG, pd);
-
-  trigger_page_fault();
-
+  log("- Dynamically allocating a struct...\n");
   struct test_struct_t* test = (struct test_struct_t*) malloc(sizeof(struct test_struct_t));
-
-  log("Dynamically allocated a struct\nAddress is: ");
+  log("  - done\n");
+  log("  - address is: ");
   print_uint32(LOG, (uint32_t) test);
   log("\n");
-
-  test->character = 'A';
-  test->string = "Hello World";
 
   uint32_t local = 0xDEADBEEF;
 
-  log("local variable at: ");
+  log("  - local variable at: ");
   print_uint32(LOG, (uint32_t) &local);
   log("\n");
-  log("local variable value: ");
+  log("  - local variable value: ");
   print_uint32(LOG, (uint32_t) local);
   log("\n");
 
   void* sp = current_stack_pointer();
-  log("stack pointer is: ");
+  log("  - stack pointer is: ");
   print_uint32(LOG, (uint32_t) sp);
   log("\n");