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#include <linux/io.h>
#include <linux/memblock.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include <asm/realmode.h>
unsigned char *real_mode_base;
struct real_mode_header real_mode_header;
void __init setup_real_mode(void)
{
phys_addr_t mem;
u16 real_mode_seg;
u32 *rel;
u32 count;
u32 *ptr;
u16 *seg;
int i;
struct real_mode_header *header =
(struct real_mode_header *) real_mode_blob;
size_t size = PAGE_ALIGN(header->end);
/* Has to be in very low memory so we can execute real-mode AP code. */
mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
if (!mem)
panic("Cannot allocate trampoline\n");
real_mode_base = __va(mem);
memblock_reserve(mem, size);
printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
real_mode_base, (unsigned long long)mem, size);
memcpy(real_mode_base, real_mode_blob, size);
real_mode_seg = __pa(real_mode_base) >> 4;
rel = (u32 *) real_mode_relocs;
/* 16-bit segment relocations. */
count = rel[0];
rel = &rel[1];
for (i = 0; i < count; i++) {
seg = (u16 *) (real_mode_base + rel[i]);
*seg = real_mode_seg;
}
/* 32-bit linear relocations. */
count = rel[i];
rel = &rel[i + 1];
for (i = 0; i < count; i++) {
ptr = (u32 *) (real_mode_base + rel[i]);
*ptr += __pa(real_mode_base);
}
/* Copied header will contain relocated physical addresses. */
memcpy(&real_mode_header, real_mode_base,
sizeof(struct real_mode_header));
#ifdef CONFIG_X86_32
*((u32 *)__va(real_mode_header.startup_32_smp)) = __pa(startup_32_smp);
*((u32 *)__va(real_mode_header.boot_gdt)) = __pa(boot_gdt);
#else
*((u64 *) __va(real_mode_header.startup_64_smp)) =
(u64) __pa(secondary_startup_64);
*((u64 *) __va(real_mode_header.level3_ident_pgt)) =
__pa(level3_ident_pgt) + _KERNPG_TABLE;
*((u64 *) __va(real_mode_header.level3_kernel_pgt)) =
__pa(level3_kernel_pgt) + _KERNPG_TABLE;
#endif
}
/*
* set_real_mode_permissions() gets called very early, to guarantee the
* availability of low memory. This is before the proper kernel page
* tables are set up, so we cannot set page permissions in that
* function. Thus, we use an arch_initcall instead.
*/
static int __init set_real_mode_permissions(void)
{
size_t all_size =
PAGE_ALIGN(real_mode_header.end) -
__pa(real_mode_base);
size_t ro_size =
PAGE_ALIGN(real_mode_header.ro_end) -
__pa(real_mode_base);
size_t text_size =
PAGE_ALIGN(real_mode_header.ro_end) -
real_mode_header.text_start;
unsigned long text_start =
(unsigned long) __va(real_mode_header.text_start);
set_memory_nx((unsigned long) real_mode_base, all_size >> PAGE_SHIFT);
set_memory_ro((unsigned long) real_mode_base, ro_size >> PAGE_SHIFT);
set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);
return 0;
}
arch_initcall(set_real_mode_permissions);
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