x86_64: move kernel

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 86 insertions, 0 deletions

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
new file mode 100644
index 000000000000..6c34bdd22e26
--- /dev/null
+++ b/arch/x86/kernel/head64.c
@@ -0,0 +1,86 @@
+/*
+ *  linux/arch/x86_64/kernel/head64.c -- prepare to run common code
+ *
+ *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/percpu.h>
+
+#include <asm/processor.h>
+#include <asm/proto.h>
+#include <asm/smp.h>
+#include <asm/bootsetup.h>
+#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)
+{
+        memset(__bss_start, 0,
+               (unsigned long) __bss_stop - (unsigned long) __bss_start);
+}
+
+#define NEW_CL_POINTER          0x228   /* Relative to real mode data */
+#define OLD_CL_MAGIC_ADDR       0x20
+#define OLD_CL_MAGIC            0xA33F
+#define OLD_CL_OFFSET           0x22
+
+static void __init copy_bootdata(char *real_mode_data)
+{
+        unsigned long new_data;
+        char * command_line;
+
+        memcpy(x86_boot_params, real_mode_data, BOOT_PARAM_SIZE);
+        new_data = *(u32 *) (x86_boot_params + NEW_CL_POINTER);
+        if (!new_data) {
+                if (OLD_CL_MAGIC != *(u16 *)(real_mode_data + OLD_CL_MAGIC_ADDR)) {
+                        return;
+                }
+                new_data = __pa(real_mode_data) + *(u16 *)(real_mode_data + OLD_CL_OFFSET);
+        }
+        command_line = __va(new_data);
+        memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
+}
+
+void __init x86_64_start_kernel(char * real_mode_data)
+{
+        int i;
+
+        /* 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");
+
+        for (i = 0; i < NR_CPUS; i++)
+                cpu_pda(i) = &boot_cpu_pda[i];
+
+        pda_init(0);
+        copy_bootdata(__va(real_mode_data));
+#ifdef CONFIG_SMP
+        cpu_set(0, cpu_online_map);
+#endif
+        start_kernel();
+}