Normally, statically allocated data goes in .bss, followed by the
initial stack, followed by HEAP. However, any data that is statically
allocated in SRAM4 with __attribute__ ((section (".sram4"))) will
clobber, and be clobbered by, the HEAP.
On STM32H7, BDMA can only access SRAM4. Therefore any BDMA buffers (or
any other data) placed in SRAM4 will expose this problem. In one case,
this manifested as a failure of NSH to start, because the SPI6 BDMA
buffers clobbered the /dev/console inode structs, which the OS
allocated earlier.
This PR ensures that only the rest of SRAM4, after any static data, is
added to the heap. This PR also allows SRAM4 to be completely excluded
from the heap by a new Kconfig, CONFIG_STM32H7_SRAM4EXCLUDE, similar
to what CONFIG_STM32H7_DTCMEXCLUDE does for the DTCM region.
Change required in linker scripts:
Every STM32H7 linker script must replace this:
.sram4 :
{
} > sram4
with this:
.sram4_reserve (NOLOAD) :
{
*(.sram4)
. = ALIGN(4);
_sram4_heap_start = ABSOLUTE(.);
} > sram4
or link will fail with: undefined reference to '_sram4_heap_start'.
The Release Notes should document this for users with out-of-tree
boards.
arch/arm/src/stm32h7/Kconfig:
* Add config STM32H7_SRAM4EXCLUDE to allow excluding all of SRAM4
from the HEAP.
arch/arm/src/stm32h7/stm32_allocateheap.c:
* Only when including SRAM4 in the heap, define HAVE_SRAM4,
SRAM4_START, SRAM4_END, and SRAM4_HEAP_START.
* Add "Private Data" section.
* Add extern for_sram4_heap_start, which must be defined in the
board's linker script.
* arm_addregion(): Only add SRAM4 to the heap when configured to
do so, i.e., unless CONFIG_STM32H7_SRAM4EXCLUDE is defined, and
only add the portion of SRAM4 that is past any static data.
boards/arm/stm32h7/nucleo-h743zi/scripts/flash.ld:
boards/arm/stm32h7/nucleo-h743zi/scripts/kernel.space.ld:
boards/arm/stm32h7/nucleo-h743zi2/scripts/flash.ld:
boards/arm/stm32h7/stm32h747i-disco/scripts/flash.ld:
boards/arm/stm32h7/stm32h747i-disco/scripts/kernel.space.ld:
* Update all in-tree STM32H7 board linker scripts as described in
"Change required in linker scripts" above.
Testing:
* Successfully built all of the following configurations:
nucleo-h743zi2:jumbo
nucleo-h743zi2:nsh
nucleo-h743zi:nxlines_oled
nucleo-h743zi:elf
nucleo-h743zi:otg_fs_host
nucleo-h743zi:nsh
nucleo-h743zi:netnsh
nucleo-h743zi:pwm
stm32h747i-disco:nsh
* Tested with custom board.
* nxstyle.
References:
[1] See the dev@nuttx.a.o mailing list discussion started 2021/03/25:
"How to ensure HEAP will not overlap static DMA buffer?"
https://lists.apache.org/thread.html/recf2bb9043f8c9f53c10917e2adb2ec64fe35dc5e6f9a695a7ac6ecc%40%3Cdev.nuttx.apache.org%3E
[2] See arm_addregion() in arch/arm/src/stm32h7/stm32_allocateheap.c
Thanks to Gregory Nutt and David Sidrane for suggestions and reviews.
In the current compilation environment, the recursive assignment(=) for compile
flags will be delayed until every file is actually need to be compile.
For example:
--------------------------------------------------------------------------------
arch/arm/src/Makefile:
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)chip}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)common}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)$(ARCH_SUBDIR)}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(TOPDIR)$(DELIM)sched}
CPPFLAGS += $(INCLUDES) $(EXTRAFLAGS)
CFLAGS += $(INCLUDES) $(EXTRAFLAGS)
CXXFLAGS += $(INCLUDES) $(EXTRAFLAGS)
AFLAGS += $(INCLUDES) $(EXTRAFLAGS)
--------------------------------------------------------------------------------
All compilation options will be included recursively,
which will be delayed until the compilation options are actually used:
tools/Config.mk:
--------------------------------------------------------------------------------
define COMPILE
@echo "CC: $1"
$(Q) $(CC) -c $(CFLAGS) $($(strip $1)_CFLAGS) $1 -o $2
endef
--------------------------------------------------------------------------------
All compile flags to be reexecuted $(INCDIR) as long as one file needs to be compiled,
but in fact, the compilation options have not changed in the current directory.
So the we recommand to change the syntax of assignment
From
Recursive (=)
To
Simple (:=)
In this way, we can ensure that all compilation options are expanded only once and reducing repeated works.
Signed-off-by: chao.an <anchao@xiaomi.com>
1.It make sense to let Toolchain.defs give the default value
2.The board can still change if the default isn't suitable
3.Avoid the same definition spread more than 200 Make.defs
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: Ic2649f1c7689bcf59c105ca8db61cad45b6e0e64
Make.defs under board folder can still overwrite the default as needed
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: I1c300a8ace4b54d475ef8d398661ed65ca273a2e
so all boards support uClibc++/libc++ automatically
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: Ibe6fafbec57f7acb26ea6188a3e9923ea82295c5
So call 'make EXTRAFLAGS=-Wno-cpp' could suppress the warnings with pre-processor
directive #warning in GCC.
Change-Id: Iaa618238924c9969bf91db22117b39e6d2fc9bb6
Signed-off-by: liuhaitao <liuhaitao@xiaomi.com>
boards/arm/stm32h7/stm32h747i-disco: Remove references to nucleo in the stm32h747i-disco board.
arch/arm/include/stm32h7, arch/arm/src/stm32h7, and boards/arm/stm32h7/stm32h747i-disco: Add support for the STM32H747I-DISCO board.
