M7350/bootable/bootloader/lk/arch/arm/mmu.c
2024-09-09 08:52:07 +00:00

102 lines
2.9 KiB
C

/*
* Copyright (c) 2008 Travis Geiselbrecht
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <debug.h>
#include <sys/types.h>
#include <compiler.h>
#include <arch.h>
#include <arch/arm.h>
#include <arch/arm/mmu.h>
#if ARM_WITH_MMU
#define MB (1024*1024)
/* the location of the table may be brought in from outside */
#if WITH_EXTERNAL_TRANSLATION_TABLE
#if !defined(MMU_TRANSLATION_TABLE_ADDR)
#error must set MMU_TRANSLATION_TABLE_ADDR in the make configuration
#endif
static uint32_t *tt = (void *)MMU_TRANSLATION_TABLE_ADDR;
#else
/* the main translation table */
static uint32_t tt[4096] __ALIGNED(16384);
#endif
void arm_mmu_map_section(addr_t paddr, addr_t vaddr, uint flags)
{
int index;
/* Get the index into the translation table */
index = vaddr / MB;
/* Set the entry value:
* (2<<0): Section entry
* (0<<5): Domain = 0
* flags: TEX, CB and AP bit settings provided by the caller.
*/
tt[index] = (paddr & ~(MB-1)) | (0<<5) | (2<<0) | flags;
arm_invalidate_tlb();
}
void arm_mmu_init(void)
{
int i;
/* set some mmu specific control bits:
* access flag disabled, TEX remap disabled, mmu disabled
*/
arm_write_cr1(arm_read_cr1() & ~((1<<29)|(1<<28)|(1<<0)));
if (platform_use_identity_mmu_mappings())
{
/* set up an identity-mapped translation table with
* strongly ordered memory type and read/write access.
*/
for (i=0; i < 4096; i++) {
arm_mmu_map_section(i * MB,
i * MB,
MMU_MEMORY_TYPE_STRONGLY_ORDERED | MMU_MEMORY_AP_READ_WRITE);
}
}
platform_init_mmu_mappings();
/* set up the translation table base */
arm_write_ttbr((uint32_t)tt);
/* set up the domain access register */
arm_write_dacr(0x00000001);
/* turn on the mmu */
arm_write_cr1(arm_read_cr1() | 0x1);
}
void arch_disable_mmu(void)
{
arm_write_cr1(arm_read_cr1() & ~(1<<0));
arm_invalidate_tlb();
}
#endif // ARM_WITH_MMU