forked from Imagelibrary/rtems
573a7202e6
This implementation disables the MMU during the modification of the translation table. This behaviour is required by boot loaders for these boards.
82 lines
1.7 KiB
C
82 lines
1.7 KiB
C
/**
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* @file
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*
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* @ingroup lpc32xx_mmu
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*
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* @brief MMU support implementation.
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*/
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/*
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* Copyright (c) 2010-2011 embedded brains GmbH. All rights reserved.
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*
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* embedded brains GmbH
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* Obere Lagerstr. 30
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* 82178 Puchheim
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* Germany
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* <rtems@embedded-brains.de>
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.com/license/LICENSE.
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*/
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#include <bsp/mmu.h>
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static uint32_t disable_mmu(void)
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{
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uint32_t ctrl = 0;
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arm_cp15_data_cache_test_and_clean_and_invalidate();
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ctrl = arm_cp15_get_control();
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arm_cp15_set_control(ctrl & ~ARM_CP15_CTRL_M);
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arm_cp15_tlb_invalidate();
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return ctrl;
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}
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static void restore_mmu_control(uint32_t ctrl)
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{
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arm_cp15_set_control(ctrl);
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}
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static uint32_t set_translation_table_entries(
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const void *begin,
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const void *end,
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uint32_t section_flags
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)
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{
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uint32_t *ttb = arm_cp15_get_translation_table_base();
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uint32_t i = ARM_MMU_SECT_GET_INDEX(begin);
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uint32_t iend = ARM_MMU_SECT_GET_INDEX(ARM_MMU_SECT_MVA_ALIGN_UP(end));
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uint32_t ctrl = disable_mmu();
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uint32_t section_flags_of_first_entry = ttb [i];
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while (i < iend) {
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ttb [i] = (i << ARM_MMU_SECT_BASE_SHIFT) | section_flags;
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++i;
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}
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restore_mmu_control(ctrl);
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return section_flags_of_first_entry;
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}
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uint32_t lpc32xx_set_translation_table_entries(
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const void *begin,
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const void *end,
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uint32_t section_flags
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)
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{
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rtems_interrupt_level level;
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uint32_t section_flags_of_first_entry = 0;
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rtems_interrupt_disable(level);
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section_flags_of_first_entry =
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set_translation_table_entries(begin, end, section_flags);
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rtems_interrupt_enable(level);
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return section_flags_of_first_entry;
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}
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