2 #include <linux/memblock.h>
4 #include <asm/cacheflush.h>
5 #include <asm/pgtable.h>
6 #include <asm/realmode.h>
8 struct real_mode_header *real_mode_header;
10 void __init setup_real_mode(void)
21 size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
23 /* Has to be in very low memory so we can execute real-mode AP code. */
24 mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
26 panic("Cannot allocate trampoline\n");
29 memblock_reserve(mem, size);
30 real_mode_header = (struct real_mode_header *) base;
32 printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
33 base, (unsigned long long)mem, size);
35 memcpy(base, real_mode_blob, size);
37 real_mode_seg = __pa(base) >> 4;
38 rel = (u32 *) real_mode_relocs;
40 /* 16-bit segment relocations. */
43 for (i = 0; i < count; i++) {
44 seg = (u16 *) (base + rel[i]);
48 /* 32-bit linear relocations. */
51 for (i = 0; i < count; i++) {
52 ptr = (u32 *) (base + rel[i]);
57 *((u32 *)__va(real_mode_header->startup_32_smp)) = __pa(startup_32_smp);
58 *((u32 *)__va(real_mode_header->boot_gdt)) = __pa(boot_gdt);
60 *((u64 *) __va(real_mode_header->startup_64_smp)) =
61 (u64)secondary_startup_64;
63 *((u64 *) __va(real_mode_header->level3_ident_pgt)) =
64 __pa(level3_ident_pgt) + _KERNPG_TABLE;
66 *((u64 *) __va(real_mode_header->level3_kernel_pgt)) =
67 __pa(level3_kernel_pgt) + _KERNPG_TABLE;
72 * set_real_mode_permissions() gets called very early, to guarantee the
73 * availability of low memory. This is before the proper kernel page
74 * tables are set up, so we cannot set page permissions in that
75 * function. Thus, we use an arch_initcall instead.
77 static int __init set_real_mode_permissions(void)
79 unsigned char *base = (unsigned char *) real_mode_header;
80 size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
83 PAGE_ALIGN(real_mode_header->ro_end) -
87 PAGE_ALIGN(real_mode_header->ro_end) -
88 real_mode_header->text_start;
90 unsigned long text_start =
91 (unsigned long) __va(real_mode_header->text_start);
93 set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);
94 set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);
95 set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);
100 arch_initcall(set_real_mode_permissions);