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SAMA5D3/4 HEAP: Add a configuration option to reserve DRAM for a framebuffer when executing out of DRAM.

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This commit is contained in:
Gregory Nutt 2014-07-08 12:43:38 -06:00
parent 25f419d487
commit e76f10ceac
2 changed files with 90 additions and 9 deletions
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36
arch/arm/src/sama5/Kconfig
View File

@ -4360,7 +4360,7 @@ config SAMA5_DDRCS_HEAP
*** DO NOT SELECT THIS OPTION IF YOU ARE EXECUTING FROM SDRAM!!**
In this case, the remaining SDRAM will automatically be added to the
heap (using RAM_END)
heap.
if SAMA5_DDRCS_HEAP
@ -4379,7 +4379,39 @@ config SAMA5_DDRCS_HEAP_SIZE
Add the region of DDR-SDRAM beginning at SAMA5_DDRCS_HEAP_OFFSET
and of size SAMA5_DDRCS_HEAP_SIZE to the heap.
endif #SAMA5_DDRCS_HEAP
endif # SAMA5_DDRCS_HEAP
config SAMA5_DDRCS_RESERVE
bool "Reserve DDR-SDRAM"
default n
depends on SAMA5_BOOT_SDRAM
---help---
This option is available only we are executing out of SDRAM. In
this case, by default, all of DRAM available from the end of the
program through the end of DRAM (RAM_START + RAM_END) is
automatically added to the heap. However, there are certain cases
where you may want to reserve a block of DRAM for other purposes
such a large DMA buffer or an LCD framebuffer. In those cases, you
can select this option to specify the end of the DRAM memory to add
to the heap; DRAM after this address will not be part of the heap
and so will be available for other purposes.
NOTE: There is way to reserve memory before the start of the
program in DRAM using this mechanism. That configuration is
possible, but not using this configuration setting.
if SAMA5_DDRCS_RESERVE
config SAMA5_DDRCS_HEAP_END
hex "DDR-SDRAM heap end"
default 0x30000000
---help---
Add the region of DDR-SDRAM beginning at the first available byte
after the memory used by the DRAM probably through this virtual
address (minus one). This will reserve the memory starting at
this address through RAM_SIZE + RAM_END for other purposes.
endif # SAMA5_DDRCS_RESERVE
config SAMA5_EBICS0_HEAP
bool "Include EBICS0 SRAM/PSRAM in heap"

63
arch/arm/src/sama5/sam_allocateheap.c
View File

@ -79,15 +79,64 @@
* the RAM region beginning at CONFIG_RAM_START. The "usable" top would
* exclude, for example, any memory reserved at the top of the for the 16KB
* page table.
*
* A special may occur when we execute from DRAM. In that case,
* CONFIG_RAM_VSTART must be set to the (virtual) start of DRAM and
* CONFIG_RAM_SIZE must be set to the size of the DRAM. These settings are
* necessary to provide the DRAM MMU mappings when the system boots and, by
* default, the DRAM memory will be added to the heap all the way up to
* CONFIG_RAM_VEND
*
* However, there are certain cases where you may want to reserve a block of
* DRAM for other purposes such a large DMA buffer or an LCD framebuffer.
* In those cases, the CONFIG_SAMA5_DDRCS_RESERVE can select a different end
* of the DRAM memory to add to the heap. If CONFIG_SAMA5_DDRCS_RESERVE is
* selected, then the setting CONFIG_SAMA5_DDRCS_HEAP_END provides the end
* (plus one) (virtual) address of memory to be added to the heap; DRAM after
* this address will not be part of the heap and so will be available for
* other purposes
*
* NOTE: There is way to reserve memory before the start of the program
* in DRAM using this mechanism. That configuration is possible, but
* not using this configuration setting.
*/
/* Memory Regions ***********************************************************/
/* Check if we have been asked to reserve memory at the end of the primary
* memory region. This option is only available if we are executing from
* DRAM and only if CONFIG_SAMA5_DDRCS_RESERVE is selected.
*/
#ifdef CONFIG_SAMA5_DDRCS_RESERVE
/* CONFIG_SAMA5_DDRCS_HEAP_END specifies the end (plus one) of the DRAM
* to add to the heap. Memory starting at CONFIG_SAMA5_DDRCS_HEAP_END
* and extending to CONFIG_RAM_VEND is then available for other purposes.
*/
# if !defined(CONFIG_SAMA5_DDRCS_HEAP_END)
# error CONFIG_SAMA5_DDRCS_HEAP_END must be defined in this configuration
# elif CONFIG_SAMA5_DDRCS_HEAP_END > CONFIG_RAM_VEND
# error CONFIG_SAMA5_DDRCS_HEAP_END is beyond CONFIG_RAM_VEND
# elif CONFIG_SAMA5_DDRCS_HEAP_END < CONFIG_RAM_VSTART
# error CONFIG_SAMA5_DDRCS_HEAP_END is before CONFIG_RAM_VSTART
# endif
# define SAMA5_PRIMARY_HEAP_END CONFIG_SAMA5_DDRCS_HEAP_END
#else
/* Otherwise, add the RAM all the way to the the end of the primary memory
* region to the heap.
*/
# define SAMA5_PRIMARY_HEAP_END CONFIG_RAM_VEND
#endif
/* We cannot use the memory for heap if it is not enabled. Or, if it is
* enabled, but does not hold SDRAM, SRAM, or PSRAM.
*
* We cannot add the region if it is if we are executing from it! In that
* case, the remainder of the memory will automatically be added to the heap
* based on g_idle_topstack and CONFIG_RAM_VEND.
* based on g_idle_topstack and SAMA5_PRIMARY_HEAP_END.
*/
#if defined(CONFIG_SAMA5_BOOT_ISRAM)
@ -207,10 +256,10 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
*/
uintptr_t ubase = (uintptr_t)USERSPACE->us_bssend + CONFIG_MM_KERNEL_HEAPSIZE;
size_t usize = CONFIG_RAM_VEND - ubase;
size_t usize = SAMA5_PRIMARY_HEAP_END - ubase;
int log2;
DEBUGASSERT(ubase < (uintptr_t)CONFIG_RAM_VEND);
DEBUGASSERT(ubase < (uintptr_t)SAMA5_PRIMARY_HEAP_END);
/* Return the user-space heap settings */
@ -225,7 +274,7 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
board_led_on(LED_HEAPALLOCATE);
*heap_start = (FAR void*)&_ebss;
*heap_size = CONFIG_RAM_VEND - (size_t)&_ebss;
*heap_size = SAMA5_PRIMARY_HEAP_END - (size_t)&_ebss;
#else
/* Both data and the heap are in ISRAM. The heap is then from the end of
@ -234,7 +283,7 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
board_led_on(LED_HEAPALLOCATE);
*heap_start = (FAR void*)g_idle_topstack;
*heap_size = CONFIG_RAM_VEND - g_idle_topstack;
*heap_size = SAMA5_PRIMARY_HEAP_END - g_idle_topstack;
#endif
}
@ -258,10 +307,10 @@ void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
*/
uintptr_t ubase = (uintptr_t)USERSPACE->us_bssend + CONFIG_MM_KERNEL_HEAPSIZE;
size_t usize = CONFIG_RAM_VEND - ubase;
size_t usize = SAMA5_PRIMARY_HEAP_END - ubase;
int log2;
DEBUGASSERT(ubase < (uintptr_t)CONFIG_RAM_VEND);
DEBUGASSERT(ubase < (uintptr_t)SAMA5_PRIMARY_HEAP_END);
/* Return the kernel heap settings (i.e., the part of the heap region
* that was not dedicated to the user heap).