[PATCH 4/6] libmm-libbsp-arm-shared. libmm low-level implementation that can be shared between many ARM targets. mminit.c contains initialization function for arm-cp15 and setup page tables. After that it enables MMU and Cache unit part of BSP initialization process. mm.c translates attributes from high-level to CPU specific attributes and apply them dynamically.
Hesham Moustafa
heshamelmatary at gmail.com
Thu Sep 12 18:10:30 UTC 2013
On Thu, Sep 12, 2013 at 3:01 PM, Gedare Bloom <gedare at rtems.org> wrote:
> On Thu, Sep 12, 2013 at 2:59 AM, Hesham AL-Matary
> <heshamelmatary at gmail.com> wrote:
> > ---
> > .../lib/libbsp/arm/shared/include/arm-cp15-start.h | 11 ++++--
> > c/src/lib/libbsp/arm/shared/mm.c | 46
> ++++++++++++++++++++++
> > c/src/lib/libbsp/arm/shared/mminit.c | 27 +++++++++++++
> > 3 files changed, 80 insertions(+), 4 deletions(-)
> > create mode 100644 c/src/lib/libbsp/arm/shared/mm.c
> > create mode 100644 c/src/lib/libbsp/arm/shared/mminit.c
> >
> > diff --git a/c/src/lib/libbsp/arm/shared/include/arm-cp15-start.h
> b/c/src/lib/libbsp/arm/shared/include/arm-cp15-start.h
> > index 01f3104..b463b1f 100644
> > --- a/c/src/lib/libbsp/arm/shared/include/arm-cp15-start.h
> > +++ b/c/src/lib/libbsp/arm/shared/include/arm-cp15-start.h
> > @@ -1,4 +1,5 @@
> > -/*
> > +/*
> > + * Copyright (c) 2013 Hesham AL-Matary.
> > * Copyright (c) 2009-2013 embedded brains GmbH. All rights reserved.
> > *
> > * embedded brains GmbH
> > @@ -89,7 +90,7 @@
> arm_cp15_start_setup_translation_table_and_enable_mmu_and_cache(
> >
> > /* Initialize translation table with invalid entries */
> Fix this comment (assuming the change below now populates the ttb with
> valid entries).
>
> > for (i = 0; i < ARM_MMU_TRANSLATION_TABLE_ENTRY_COUNT; ++i) {
> > - ttb [i] = 0;
> > + ttb [i] = (i << ARM_MMU_SECT_BASE_SHIFT) |
> ARMV7_MMU_DATA_READ_WRITE;
> > }
> >
> > for (i = 0; i < config_count; ++i) {
> > @@ -97,11 +98,13 @@
> arm_cp15_start_setup_translation_table_and_enable_mmu_and_cache(
> > }
> >
> > /* Enable MMU and cache */
> > - ctrl |= ARM_CP15_CTRL_I | ARM_CP15_CTRL_C | ARM_CP15_CTRL_M;
> > + ctrl |= ARM_CP15_CTRL_AFE | ARM_CP15_CTRL_S | ARM_CP15_CTRL_I |
> > + ARM_CP15_CTRL_C | ARM_CP15_CTRL_M | ARM_CP15_CTRL_XP;
> > +
> > arm_cp15_set_control(ctrl);
> > }
> >
> > -BSP_START_TEXT_SECTION static inline uint32_t
> > +BSP_START_TEXT_SECTION inline uint32_t
> undo this change.
>
I already did, but that caused undefined reference to arm_
cp15_start_setup_mmu_and_cache
compilation error at arm-a9mpcore-start.h:89 when I was compiling realview
with --enable-smp
option.
> > arm_cp15_start_setup_mmu_and_cache(uint32_t ctrl_clear, uint32_t
> ctrl_set)
> > {
> > uint32_t ctrl = arm_cp15_get_control();
> > diff --git a/c/src/lib/libbsp/arm/shared/mm.c
> b/c/src/lib/libbsp/arm/shared/mm.c
> > new file mode 100644
> > index 0000000..36e90be
> > --- /dev/null
> > +++ b/c/src/lib/libbsp/arm/shared/mm.c
> > @@ -0,0 +1,46 @@
> > +/*
> > + * Copyright (c) 2013 Hesham AL-Matary.
> > + *
> > + * 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/mm.h>
> > +#include <libcpu/arm-cp15.h>
> > +#include <rtems/score/mm.h>
> > +
> > +#define LIBMM_REGION_IS_CACHE_ENABLED(attr) \
> > + (((attr) >> RTEMS_MM_REGION_BIT_CACHE) & 1U)
> > +#define LIBMM_REGION_IS_PROTECTION_WRITE_ENABLED(attr) \
> > + (((attr) >> RTEMS_MM_REGION_BIT_WRITE) & 1U)
> > +#define LIBMM_REGION_IS_DEVICE_TYPE(attr) \
> > + (((attr) >> RTEMS_MM_REGION_BIT_DEVICE) & 1U)
> > +#define LIBMM_REGION_IS_SHARED_MEMORY(attr) \
> > + (((attr) >> RTEMS_MM_REGION_BIT_SHARED) & 1U)
> > +
> Should these macros be provided by the score/mm.h?
>
> mm.h or mmimpl.h whatever. It's used by applications calls as well as
mm.c which used these definitions to translate attributes to CPU specific
ones.
> > +#define ARM_MMU_BIND_SECTION_TO_CLIENT_DOMAIN \
> > + (ARM_MMU_DEFAULT_CLIENT_DOMAIN << ARM_MMU_SECT_DOMAIN_SHIFT)
> > +
> > +#define LIBMM_TRANSLATE_ATTRIBUTES_TO_CPU(attr) \
> > + ((ARM_MMU_BIND_SECTION_TO_CLIENT_DOMAIN) \
> > + | (ARM_MMU_SECT_AP_0) \
> > + | (LIBMM_REGION_IS_PROTECTION_WRITE_ENABLED(attr) ? \
> > + 0U : (ARM_MMU_SECT_AP_2)) \
> > + | (LIBMM_REGION_IS_CACHE_ENABLED(attr) ? \
> > + (ARM_MMU_SECT_TEX_0|ARM_MMU_SECT_C|ARM_MMU_SECT_B) : 0U) \
> > + | (LIBMM_REGION_IS_DEVICE_TYPE(attr) ? ARM_MMU_SECT_B : 0U) \
> > + | (LIBMM_REGION_IS_SHARED_MEMORY(attr) ? ARM_MMU_SECT_S : 0U) \
> > + | (ARM_MMU_SECT_DEFAULT))
> > +
> This macro could properly be named something simpler since it is local
> to this .c file.
>
> Sure, I just wanted to give it a self-describing name.
> > +void bsp_memory_management_set_attributes(
> > + uintptr_t base,
> > + size_t size,
> > + uint32_t attr
> > +)
> > +{
> > + uintptr_t end = (uint32_t)base + (uint32_t)size;
> Don't cast base and size here.
>
> > + uint32_t section_flags = LIBMM_TRANSLATE_ATTRIBUTES_TO_CPU(attr);
> > +
> > + arm_cp15_set_translation_table_entries(base, end, section_flags);
> > +}
> > diff --git a/c/src/lib/libbsp/arm/shared/mminit.c
> b/c/src/lib/libbsp/arm/shared/mminit.c
> > new file mode 100644
> > index 0000000..333d65c
> > --- /dev/null
> > +++ b/c/src/lib/libbsp/arm/shared/mminit.c
> > @@ -0,0 +1,27 @@
> > +/*
> > + * Copyright (c) 2013 Hesham AL-Matary.
> > + *
> > + * 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/arm-cp15-start.h>
> > +#include <bsp/linker-symbols.h>
> > +#include <bsp/mm.h>
> > +#include <bsp/start.h>
> > +
> > +extern const mm_init_start_config bsp_mm_config_table[];
> > +extern const size_t bsp_mm_config_table_size;
> > +
> > +BSP_START_TEXT_SECTION void bsp_memory_management_initialize(void)
> > +{
> > + uint32_t ctrl = arm_cp15_get_control();
> > +
> > + arm_cp15_start_setup_translation_table_and_enable_mmu_and_cache(
> > + ctrl,
> > + (uint32_t *) bsp_translation_table_base,
> > + ARM_MMU_DEFAULT_CLIENT_DOMAIN,
> > + &bsp_mm_config_table[0],
> > + bsp_mm_config_table_size
> > + );
> Fix indentation level of nested lines of arguments. Also, this
> mminit.c file does not make sense until you add at least one of the
> ARM bsps using it.
>
> realview, xilinx, and raspberry currently
calls the initialization function within this
mminit.c
> > +}
> > --
> > 1.8.3.1
> >
> > _______________________________________________
> > rtems-devel mailing list
> > rtems-devel at rtems.org
> > http://www.rtems.org/mailman/listinfo/rtems-devel
>
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