/**
* \brief Reset kernel paging.
*
* This function resets the page maps for kernel and memory-space. It clears out
* all other mappings. Use this only at system bootup!
*/
void paging_arm_reset(lpaddr_t paddr, size_t bytes)
{
// make sure kernel pagetable is aligned to 16K after relocation
aligned_kernel_l1_table = (union arm_l1_entry *)ROUND_UP((uintptr_t)kernel_l1_table, ARM_L1_ALIGN);
// make sure low l2 pagetable is aligned to 1K after relocation
aligned_low_l2_table = (union arm_l2_entry *)ROUND_UP((uintptr_t)low_l2_table, ARM_L2_ALIGN);
// Re-map physical memory
paging_map_memory((uintptr_t)aligned_kernel_l1_table, paddr, bytes);
// map first MB at granularity of 4K pages
uint32_t l2_flags = ARM_L2_SMALL_USR_NONE | ARM_L2_SMALL_CACHEABLE | ARM_L2_SMALL_BUFFERABLE;
paging_map_user_pages_l1((uintptr_t)aligned_kernel_l1_table, MEMORY_OFFSET,
mem_to_local_phys((uintptr_t)aligned_low_l2_table));
for(lpaddr_t pa=0; pa < ARM_L1_SECTION_BYTES; pa += BYTES_PER_PAGE)
{
lvaddr_t va = pa + MEMORY_OFFSET;
paging_set_l2_entry((uintptr_t *)&aligned_low_l2_table[ARM_L2_OFFSET(va)], pa, l2_flags);
}
// map high-mem relocated exception vector to corresponding page in low MB
// core 0: 0xffff0000 -> 0x80000
// core 1: 0xffff0000 -> 0x81000
// ...
paging_map_user_pages_l1((uintptr_t)aligned_kernel_l1_table, ETABLE_ADDR,
mem_to_local_phys((uintptr_t)aligned_low_l2_table));
int core_id = hal_get_cpu_id();
lpaddr_t addr = ETABLE_PHYS_BASE + core_id * BASE_PAGE_SIZE;
paging_set_l2_entry((uintptr_t *)&aligned_low_l2_table[ARM_L2_OFFSET(ETABLE_ADDR)], addr, l2_flags);
cp15_write_ttbr1(mem_to_local_phys((uintptr_t)aligned_kernel_l1_table));
cp15_invalidate_tlb();
}
/**
* Map frames into init process address space. Init has a contiguous set of
* l2 entries so this is straightforward.
*
* @param l2_table pointer to init's L2 table.
* @param l2_base virtual address represented by first L2 table entry
* @param va_base virtual address to map.
* @param pa_base physical address to associate with virtual address.
* @param bytes number of bytes to map.
* @param l2_flags ARM L2 small page flags for mapped pages.
*/
static void
spawn_init_map(union arm_l2_entry* l2_table,
lvaddr_t l2_base,
lvaddr_t va_base,
lpaddr_t pa_base,
size_t bytes,
uintptr_t l2_flags)
{
assert(va_base >= l2_base);
assert(0 == (va_base & (BASE_PAGE_SIZE - 1)));
assert(0 == (pa_base & (BASE_PAGE_SIZE - 1)));
assert(0 == (bytes & (BASE_PAGE_SIZE - 1)));
int bi = (va_base - l2_base) / BASE_PAGE_SIZE;
int li = bi + bytes / BASE_PAGE_SIZE;
while (bi < li)
{
paging_set_l2_entry((uintptr_t *)&l2_table[bi], pa_base, l2_flags);
pa_base += BASE_PAGE_SIZE;
bi++;
}
}