1 /* 2 * prepare to run common code 3 * 4 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE 5 */ 6 7 #include <linux/init.h> 8 #include <linux/linkage.h> 9 #include <linux/types.h> 10 #include <linux/kernel.h> 11 #include <linux/string.h> 12 #include <linux/percpu.h> 13 #include <linux/start_kernel.h> 14 #include <linux/io.h> 15 #include <linux/memblock.h> 16 17 #include <asm/processor.h> 18 #include <asm/proto.h> 19 #include <asm/smp.h> 20 #include <asm/setup.h> 21 #include <asm/desc.h> 22 #include <asm/pgtable.h> 23 #include <asm/tlbflush.h> 24 #include <asm/sections.h> 25 #include <asm/kdebug.h> 26 #include <asm/e820.h> 27 #include <asm/bios_ebda.h> 28 #include <asm/bootparam_utils.h> 29 30 static void __init zap_identity_mappings(void) 31 { 32 pgd_t *pgd = pgd_offset_k(0UL); 33 pgd_clear(pgd); 34 __flush_tlb_all(); 35 } 36 37 /* Don't add a printk in there. printk relies on the PDA which is not initialized 38 yet. */ 39 static void __init clear_bss(void) 40 { 41 memset(__bss_start, 0, 42 (unsigned long) __bss_stop - (unsigned long) __bss_start); 43 } 44 45 static void __init copy_bootdata(char *real_mode_data) 46 { 47 char * command_line; 48 49 memcpy(&boot_params, real_mode_data, sizeof boot_params); 50 sanitize_boot_params(&boot_params); 51 if (boot_params.hdr.cmd_line_ptr) { 52 command_line = __va(boot_params.hdr.cmd_line_ptr); 53 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); 54 } 55 } 56 57 void __init x86_64_start_kernel(char * real_mode_data) 58 { 59 int i; 60 61 /* 62 * Build-time sanity checks on the kernel image and module 63 * area mappings. (these are purely build-time and produce no code) 64 */ 65 BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START); 66 BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE); 67 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); 68 BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0); 69 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0); 70 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); 71 BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == 72 (__START_KERNEL & PGDIR_MASK))); 73 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END); 74 75 /* clear bss before set_intr_gate with early_idt_handler */ 76 clear_bss(); 77 78 /* Make NULL pointers segfault */ 79 zap_identity_mappings(); 80 81 max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT; 82 83 for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) { 84 #ifdef CONFIG_EARLY_PRINTK 85 set_intr_gate(i, &early_idt_handlers[i]); 86 #else 87 set_intr_gate(i, early_idt_handler); 88 #endif 89 } 90 load_idt((const struct desc_ptr *)&idt_descr); 91 92 if (console_loglevel == 10) 93 early_printk("Kernel alive\n"); 94 95 x86_64_start_reservations(real_mode_data); 96 } 97 98 void __init x86_64_start_reservations(char *real_mode_data) 99 { 100 copy_bootdata(__va(real_mode_data)); 101 102 memblock_reserve(__pa_symbol(&_text), 103 __pa_symbol(&__bss_stop) - __pa_symbol(&_text)); 104 105 #ifdef CONFIG_BLK_DEV_INITRD 106 /* Reserve INITRD */ 107 if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) { 108 /* Assume only end is not page aligned */ 109 unsigned long ramdisk_image = boot_params.hdr.ramdisk_image; 110 unsigned long ramdisk_size = boot_params.hdr.ramdisk_size; 111 unsigned long ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size); 112 memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image); 113 } 114 #endif 115 116 reserve_ebda_region(); 117 118 /* 119 * At this point everything still needed from the boot loader 120 * or BIOS or kernel text should be early reserved or marked not 121 * RAM in e820. All other memory is free game. 122 */ 123 124 start_kernel(); 125 } 126