1
2
3
4
5
6
7
8
9
10
11
12
13
/*
 * Map the kernel image (starting with PHYS_OFFSET).
 */
adrp	x0, init_pg_dir
mov_q	x5, KIMAGE_VADDR + TEXT_OFFSET	// compile time __va(_text)
add	x5, x5, x23			// add KASLR displacement
mov	x4, PTRS_PER_PGD
adrp	x6, _end			// runtime __pa(_end)
adrp	x3, _text			// runtime __pa(_text)
sub	x6, x6, x3			// _end - _text
add	x6, x6, x5			// runtime __va(_end)

map_memory x0, x1, x5, x6, x7, x3, x4, x10, x11, x12, x13, x14

1
2
3
4
5
6
7
8
9
10
11
12
13
.macro map_memory, tbl, rtbl, vstart, vend, flags, phys, pgds, istart, iend, tmp, count, sv
	...
#if SWAPPER_PGTABLE_LEVELS > 3
	compute_indices \vstart, \vend, #PUD_SHIFT, #PTRS_PER_PUD, \istart, \iend, \count
	populate_entries \tbl, \rtbl, \istart, \iend, #PMD_TYPE_TABLE, #PAGE_SIZE, \tmp
	mov \tbl, \sv
	mov \sv, \rtbl
#endif
#if SWAPPER_PGTABLE_LEVELS > 2
	compute_indices \vstart, \vend, #SWAPPER_TABLE_SHIFT, #PTRS_PER_PMD, \istart, \iend, \count
	populate_entries \tbl, \rtbl, \istart, \iend, #PMD_TYPE_TABLE, #PAGE_SIZE, \tmp
	mov \tbl, \sv
#endif

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
phys_addr_t pgd_phys = early_pgtable_alloc();
pgd_t *pgdp = pgd_set_fixmap(pgd_phys);

map_kernel(pgdp);
map_mem(pgdp);

/*
 * We want to reuse the original swapper_pg_dir so we don't have to
 * communicate the new address to non-coherent secondaries in
 * secondary_entry, and so cpu_switch_mm can generate the address with
 * adrp+add rather than a load from some global variable.
 *
 * To do this we need to go via a temporary pgd.
 */
cpu_replace_ttbr1(__va(pgd_phys));
memcpy(swapper_pg_dir, pgdp, PGD_SIZE);
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));

pgd_clear_fixmap();
memblock_free(pgd_phys, PAGE_SIZE);
	/*
 * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd
 * allocated with it.
 */
memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE,
	      __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir)
	      - PAGE_SIZE);