/** Initializes page tables.
*
* 1:1 virtual-physical mapping is created in kernel address space. Mapping
* for table with exception vectors is also created.
*/
void page_arch_init(void)
{
int flags = PAGE_CACHEABLE;
page_mapping_operations = &pt_mapping_operations;
page_table_lock(AS_KERNEL, true);
uintptr_t cur;
/* Kernel identity mapping */
for (cur = PHYSMEM_START_ADDR;
cur < min(config.identity_size, config.physmem_end);
cur += FRAME_SIZE)
page_mapping_insert(AS_KERNEL, PA2KA(cur), cur, flags);
#ifdef HIGH_EXCEPTION_VECTORS
/* Create mapping for exception table at high offset */
uintptr_t ev_frame = (uintptr_t) frame_alloc(ONE_FRAME, FRAME_NONE);
page_mapping_insert(AS_KERNEL, EXC_BASE_ADDRESS, ev_frame, flags);
#else
#error "Only high exception vector supported now"
#endif
page_table_unlock(AS_KERNEL, true);
as_switch(NULL, AS_KERNEL);
boot_page_table_free();
}
void page_arch_init(void)
{
int flags = PAGE_CACHEABLE | PAGE_EXEC;
page_mapping_operations = &pt_mapping_operations;
page_table_lock(AS_KERNEL, true);
/* Kernel identity mapping */
// FIXME:
// We need to consider the possibility that
// identity_base > identity_size and physmem_end.
// This might lead to overflow if identity_size is too big.
for (uintptr_t cur = PHYSMEM_START_ADDR;
cur < min(KA2PA(config.identity_base) +
config.identity_size, config.physmem_end);
cur += FRAME_SIZE)
page_mapping_insert(AS_KERNEL, PA2KA(cur), cur, flags);
page_table_unlock(AS_KERNEL, true);
as_switch(NULL, AS_KERNEL);
/* Switch MMU to new context table */
asi_u32_write(ASI_MMUREGS, MMU_CONTEXT_TABLE, KA2PA(as_context_table) >> 4);
}