2 * prepare to run common code
4 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
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>
16 #include <asm/processor.h>
17 #include <asm/proto.h>
19 #include <asm/setup.h>
21 #include <asm/pgtable.h>
22 #include <asm/tlbflush.h>
23 #include <asm/sections.h>
24 #include <asm/kdebug.h>
26 #include <asm/bios_ebda.h>
29 static struct x8664_pda _boot_cpu_pda __read_mostly;
32 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
34 * We install an empty cpu_pda pointer table to trap references before
35 * the actual cpu_pda pointer table is created in setup_cpu_pda_map().
37 static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata;
39 static struct x8664_pda *__cpu_pda[1] __read_mostly;
42 #else /* !CONFIG_SMP (NR_CPUS will be 1) */
43 static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly;
46 static void __init zap_identity_mappings(void)
48 pgd_t *pgd = pgd_offset_k(0UL);
53 /* Don't add a printk in there. printk relies on the PDA which is not initialized
55 static void __init clear_bss(void)
57 memset(__bss_start, 0,
58 (unsigned long) __bss_stop - (unsigned long) __bss_start);
61 static void __init copy_bootdata(char *real_mode_data)
65 memcpy(&boot_params, real_mode_data, sizeof boot_params);
66 if (boot_params.hdr.cmd_line_ptr) {
67 command_line = __va(boot_params.hdr.cmd_line_ptr);
68 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
72 #define BIOS_LOWMEM_KILOBYTES 0x413
75 * The BIOS places the EBDA/XBDA at the top of conventional
76 * memory, and usually decreases the reported amount of
77 * conventional memory (int 0x12) too. This also contains a
78 * workaround for Dell systems that neglect to reserve EBDA.
79 * The same workaround also avoids a problem with the AMD768MPX
80 * chipset: reserve a page before VGA to prevent PCI prefetch
81 * into it (errata #56). Usually the page is reserved anyways,
82 * unless you have no PS/2 mouse plugged in.
84 static void __init reserve_ebda_region(void)
86 unsigned int lowmem, ebda_addr;
88 /* To determine the position of the EBDA and the */
89 /* end of conventional memory, we need to look at */
90 /* the BIOS data area. In a paravirtual environment */
91 /* that area is absent. We'll just have to assume */
92 /* that the paravirt case can handle memory setup */
93 /* correctly, without our help. */
94 if (paravirt_enabled())
97 /* end of low (conventional) memory */
98 lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
101 /* start of EBDA area */
102 ebda_addr = get_bios_ebda();
104 /* Fixup: bios puts an EBDA in the top 64K segment */
105 /* of conventional memory, but does not adjust lowmem. */
106 if ((lowmem - ebda_addr) <= 0x10000)
109 /* Fixup: bios does not report an EBDA at all. */
110 /* Some old Dells seem to need 4k anyhow (bugzilla 2990) */
111 if ((ebda_addr == 0) && (lowmem >= 0x9f000))
114 /* Paranoia: should never happen, but... */
115 if ((lowmem == 0) || (lowmem >= 0x100000))
118 /* reserve all memory between lowmem and the 1MB mark */
119 reserve_early(lowmem, 0x100000, "BIOS reserved");
122 static void __init reserve_setup_data(void)
124 struct setup_data *data;
125 unsigned long pa_data;
128 if (boot_params.hdr.version < 0x0209)
130 pa_data = boot_params.hdr.setup_data;
132 data = early_ioremap(pa_data, sizeof(*data));
133 sprintf(buf, "setup data %x", data->type);
134 reserve_early(pa_data, pa_data+sizeof(*data)+data->len, buf);
135 pa_data = data->next;
136 early_iounmap(data, sizeof(*data));
140 void __init x86_64_start_kernel(char * real_mode_data)
145 * Build-time sanity checks on the kernel image and module
146 * area mappings. (these are purely build-time and produce no code)
148 BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
149 BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
150 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
151 BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
152 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
153 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
154 BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
155 (__START_KERNEL & PGDIR_MASK)));
157 /* clear bss before set_intr_gate with early_idt_handler */
160 /* Make NULL pointers segfault */
161 zap_identity_mappings();
163 /* Cleanup the over mapped high alias */
166 for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
167 #ifdef CONFIG_EARLY_PRINTK
168 set_intr_gate(i, &early_idt_handlers[i]);
170 set_intr_gate(i, early_idt_handler);
173 load_idt((const struct desc_ptr *)&idt_descr);
175 early_printk("Kernel alive\n");
177 _cpu_pda = __cpu_pda;
178 cpu_pda(0) = &_boot_cpu_pda;
181 early_printk("Kernel really alive\n");
183 copy_bootdata(__va(real_mode_data));
185 reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");
187 #ifdef CONFIG_BLK_DEV_INITRD
189 if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
190 unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
191 unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
192 unsigned long ramdisk_end = ramdisk_image + ramdisk_size;
193 reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
197 reserve_ebda_region();
198 reserve_setup_data();
201 * At this point everything still needed from the boot loader
202 * or BIOS or kernel text should be early reserved or marked not
203 * RAM in e820. All other memory is free game.