diff options
Diffstat (limited to 'bsps/arm/lpc32xx/start/mmu.c')
-rw-r--r-- | bsps/arm/lpc32xx/start/mmu.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/bsps/arm/lpc32xx/start/mmu.c b/bsps/arm/lpc32xx/start/mmu.c new file mode 100644 index 0000000000..0c2f355a45 --- /dev/null +++ b/bsps/arm/lpc32xx/start/mmu.c @@ -0,0 +1,81 @@ +/** + * @file + * + * @ingroup lpc32xx_mmu + * + * @brief MMU support implementation. + */ + +/* + * Copyright (c) 2010-2011 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Obere Lagerstr. 30 + * 82178 Puchheim + * Germany + * <rtems@embedded-brains.de> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + */ + +#include <bsp/mmu.h> + +static uint32_t disable_mmu(void) +{ + uint32_t ctrl = 0; + + arm_cp15_data_cache_test_and_clean_and_invalidate(); + + ctrl = arm_cp15_get_control(); + arm_cp15_set_control(ctrl & ~ARM_CP15_CTRL_M); + + arm_cp15_tlb_invalidate(); + + return ctrl; +} + +static void restore_mmu_control(uint32_t ctrl) +{ + arm_cp15_set_control(ctrl); +} + +static uint32_t set_translation_table_entries( + const void *begin, + const void *end, + uint32_t section_flags +) +{ + uint32_t *ttb = arm_cp15_get_translation_table_base(); + uint32_t i = ARM_MMU_SECT_GET_INDEX(begin); + uint32_t iend = ARM_MMU_SECT_GET_INDEX(ARM_MMU_SECT_MVA_ALIGN_UP(end)); + uint32_t ctrl = disable_mmu(); + uint32_t section_flags_of_first_entry = ttb [i]; + + while (i < iend) { + ttb [i] = (i << ARM_MMU_SECT_BASE_SHIFT) | section_flags; + ++i; + } + + restore_mmu_control(ctrl); + + return section_flags_of_first_entry; +} + +uint32_t lpc32xx_set_translation_table_entries( + const void *begin, + const void *end, + uint32_t section_flags +) +{ + rtems_interrupt_level level; + uint32_t section_flags_of_first_entry = 0; + + rtems_interrupt_disable(level); + section_flags_of_first_entry = + set_translation_table_entries(begin, end, section_flags); + rtems_interrupt_enable(level); + + return section_flags_of_first_entry; +} |