aboutsummaryrefslogtreecommitdiff
path: root/arch/x86_64/kernel/head64.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86_64/kernel/head64.c')
-rw-r--r--arch/x86_64/kernel/head64.c41
1 files changed, 26 insertions, 15 deletions
diff --git a/arch/x86_64/kernel/head64.c b/arch/x86_64/kernel/head64.c
index 5f197b0a330..213d90e0475 100644
--- a/arch/x86_64/kernel/head64.c
+++ b/arch/x86_64/kernel/head64.c
@@ -18,8 +18,16 @@
#include <asm/setup.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
#include <asm/sections.h>
+static void __init zap_identity_mappings(void)
+{
+ pgd_t *pgd = pgd_offset_k(0UL);
+ pgd_clear(pgd);
+ __flush_tlb();
+}
+
/* Don't add a printk in there. printk relies on the PDA which is not initialized
yet. */
static void __init clear_bss(void)
@@ -29,25 +37,24 @@ static void __init clear_bss(void)
}
#define NEW_CL_POINTER 0x228 /* Relative to real mode data */
-#define OLD_CL_MAGIC_ADDR 0x90020
+#define OLD_CL_MAGIC_ADDR 0x20
#define OLD_CL_MAGIC 0xA33F
-#define OLD_CL_BASE_ADDR 0x90000
-#define OLD_CL_OFFSET 0x90022
+#define OLD_CL_OFFSET 0x22
static void __init copy_bootdata(char *real_mode_data)
{
- int new_data;
+ unsigned long new_data;
char * command_line;
memcpy(x86_boot_params, real_mode_data, BOOT_PARAM_SIZE);
- new_data = *(int *) (x86_boot_params + NEW_CL_POINTER);
+ new_data = *(u32 *) (x86_boot_params + NEW_CL_POINTER);
if (!new_data) {
- if (OLD_CL_MAGIC != * (u16 *) OLD_CL_MAGIC_ADDR) {
+ if (OLD_CL_MAGIC != *(u16 *)(real_mode_data + OLD_CL_MAGIC_ADDR)) {
return;
}
- new_data = OLD_CL_BASE_ADDR + * (u16 *) OLD_CL_OFFSET;
+ new_data = __pa(real_mode_data) + *(u16 *)(real_mode_data + OLD_CL_OFFSET);
}
- command_line = (char *) ((u64)(new_data));
+ command_line = __va(new_data);
memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
}
@@ -55,26 +62,30 @@ void __init x86_64_start_kernel(char * real_mode_data)
{
int i;
+ /*
+ * Make sure kernel is aligned to 2MB address. Catching it at compile
+ * time is better. Change your config file and compile the kernel
+ * for a 2MB aligned address (CONFIG_PHYSICAL_START)
+ */
+ BUILD_BUG_ON(CONFIG_PHYSICAL_START & (__KERNEL_ALIGN - 1));
+
/* clear bss before set_intr_gate with early_idt_handler */
clear_bss();
+ /* Make NULL pointers segfault */
+ zap_identity_mappings();
+
for (i = 0; i < IDT_ENTRIES; i++)
set_intr_gate(i, early_idt_handler);
asm volatile("lidt %0" :: "m" (idt_descr));
early_printk("Kernel alive\n");
- /*
- * switch to init_level4_pgt from boot_level4_pgt
- */
- memcpy(init_level4_pgt, boot_level4_pgt, PTRS_PER_PGD*sizeof(pgd_t));
- asm volatile("movq %0,%%cr3" :: "r" (__pa_symbol(&init_level4_pgt)));
-
for (i = 0; i < NR_CPUS; i++)
cpu_pda(i) = &boot_cpu_pda[i];
pda_init(0);
- copy_bootdata(real_mode_data);
+ copy_bootdata(__va(real_mode_data));
#ifdef CONFIG_SMP
cpu_set(0, cpu_online_map);
#endif