80 lines
1.9 KiB
C
80 lines
1.9 KiB
C
|
#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));
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* 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);
|
||
|
|
|
||
|
|
set_memory_x((unsigned long) real_mode_base, all_size >> PAGE_SHIFT);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
arch_initcall(set_real_mode_permissions);
|