nuttx/boards/arm/stm32h7/stm32h747i-disco/scripts/flash.ld
Nathan Hartman 4716fc929d arch/stm32h7 - Fix HEAP clobbering static data in SRAM4
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.
2021-03-30 17:22:46 -03:00

199 lines
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/****************************************************************************
* boards/arm/stm32h7/stm32h747i-disco/scripts/flash.ld
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/* The STM32H747XI has 2048Kb of main FLASH memory. The flash memory is
* partitioned into a User Flash memory and a System Flash memory. Each
* of these memories has two banks:
*
* 1) User Flash memory:
*
* Bank 1: Start address 0x0800:0000 to 0x080F:FFFF with 8 sectors, 128Kb each
* Bank 2: Start address 0x0810:0000 to 0x081F:FFFF with 8 sectors, 128Kb each
*
* 2) System Flash memory:
*
* Bank 1: Start address 0x1FF0:0000 to 0x1FF1:FFFF with 1 x 128Kb sector
* Bank 1: Start address 0x1FF4:0000 to 0x1FF5:FFFF with 1 x 128Kb sector
*
* 3) User option bytes for user configuration, only in Bank 1.
*
* In the STM32H747XI, two different boot spaces can be selected through
* the BOOT pin and the boot base address programmed in the BOOT_ADD0 and
* BOOT_ADD1 option bytes:
*
* 1) BOOT=0: Boot address defined by user option byte BOOT_ADD0[15:0].
* ST programmed value: Flash memory at 0x0800:0000
* 2) BOOT=1: Boot address defined by user option byte BOOT_ADD1[15:0].
* ST programmed value: System bootloader at 0x1FF0:0000
*
* NuttX does not modify these option bytes. On the unmodified STM32H747I-DISCO
* board, the BOOT0 pin is at ground so by default, the STM32 will boot
* to address 0x0800:0000 in FLASH.
*
* The STM32H747XI also has 1024Kb of data SRAM.
* SRAM is split up into several blocks and into three power domains:
*
* 1) TCM SRAMs are dedicated to the Cortex-M7 and are accessible with
* 0 wait states by the Cortex-M7 and by MDMA through AHBS slave bus
*
* 1.1) 128Kb of DTCM-RAM beginning at address 0x2000:0000
*
* The DTCM-RAM is organized as 2 x 64Kb DTCM-RAMs on 2 x 32 bit
* DTCM ports. The DTCM-RAM could be used for critical real-time
* data, such as interrupt service routines or stack / heap memory.
* Both DTCM-RAMs can be used in parallel (for load/store operations)
* thanks to the Cortex-M7 dual issue capability.
*
* 1.2) 64Kb of ITCM-RAM beginning at address 0x0000:0000
*
* This RAM is connected to ITCM 64-bit interface designed for
* execution of critical real-times routines by the CPU.
*
* 2) AXI SRAM (D1 domain) accessible by all system masters except BDMA
* through D1 domain AXI bus matrix
*
* 2.1) 512Kb of SRAM beginning at address 0x2400:0000
*
* 3) AHB SRAM (D2 domain) accessible by all system masters except BDMA
* through D2 domain AHB bus matrix
*
* 3.1) 128Kb of SRAM1 beginning at address 0x3000:0000
* 3.2) 128Kb of SRAM2 beginning at address 0x3002:0000
* 3.3) 32Kb of SRAM3 beginning at address 0x3004:0000
*
* SRAM1 - SRAM3 are one contiguous block: 288Kb at address 0x3000:0000
*
* 4) AHB SRAM (D3 domain) accessible by most of system masters
* through D3 domain AHB bus matrix
*
* 4.1) 64Kb of SRAM4 beginning at address 0x3800:0000
* 4.1) 4Kb of backup RAM beginning at address 0x3880:0000
*
* When booting from FLASH, FLASH memory is aliased to address 0x0000:0000
* where the code expects to begin execution by jumping to the entry point in
* the 0x0800:0000 address range.
*/
MEMORY
{
itcm (rwx) : ORIGIN = 0x00000000, LENGTH = 64K
flash (rx) : ORIGIN = 0x08000000, LENGTH = 2048K
dtcm1 (rwx) : ORIGIN = 0x20000000, LENGTH = 64K
dtcm2 (rwx) : ORIGIN = 0x20010000, LENGTH = 64K
sram (rwx) : ORIGIN = 0x24000000, LENGTH = 512K
sram1 (rwx) : ORIGIN = 0x30000000, LENGTH = 128K
sram2 (rwx) : ORIGIN = 0x30020000, LENGTH = 128K
sram3 (rwx) : ORIGIN = 0x30040000, LENGTH = 32K
sram4 (rwx) : ORIGIN = 0x38000000, LENGTH = 64K
bbram (rwx) : ORIGIN = 0x38800000, LENGTH = 4K
}
OUTPUT_ARCH(arm)
EXTERN(_vectors)
ENTRY(_stext)
SECTIONS
{
.text :
{
_stext = ABSOLUTE(.);
*(.vectors)
*(.text .text.*)
*(.fixup)
*(.gnu.warning)
*(.rodata .rodata.*)
*(.gnu.linkonce.t.*)
*(.glue_7)
*(.glue_7t)
*(.got)
*(.gcc_except_table)
*(.gnu.linkonce.r.*)
_etext = ABSOLUTE(.);
} > flash
.init_section :
{
_sinit = ABSOLUTE(.);
*(.init_array .init_array.*)
_einit = ABSOLUTE(.);
} > flash
.ARM.extab :
{
*(.ARM.extab*)
} > flash
__exidx_start = ABSOLUTE(.);
.ARM.exidx :
{
*(.ARM.exidx*)
} > flash
__exidx_end = ABSOLUTE(.);
_eronly = ABSOLUTE(.);
.data :
{
_sdata = ABSOLUTE(.);
*(.data .data.*)
*(.gnu.linkonce.d.*)
CONSTRUCTORS
. = ALIGN(4);
_edata = ABSOLUTE(.);
} > sram AT > flash
.bss :
{
_sbss = ABSOLUTE(.);
*(.bss .bss.*)
*(.gnu.linkonce.b.*)
*(COMMON)
. = ALIGN(4);
_ebss = ABSOLUTE(.);
} > sram
/* Emit the the D3 power domain section for locating BDMA data
*
* Static data with __attribute__ ((section (".sram4"))) will be located
* at start of SRAM4; the rest of SRAM4 will be added to the heap.
*/
.sram4_reserve (NOLOAD) :
{
*(.sram4)
. = ALIGN(4);
_sram4_heap_start = ABSOLUTE(.);
} > sram4
/* Stabs debugging sections. */
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
.stab.exclstr 0 : { *(.stab.exclstr) }
.stab.index 0 : { *(.stab.index) }
.stab.indexstr 0 : { *(.stab.indexstr) }
.comment 0 : { *(.comment) }
.debug_abbrev 0 : { *(.debug_abbrev) }
.debug_info 0 : { *(.debug_info) }
.debug_line 0 : { *(.debug_line) }
.debug_pubnames 0 : { *(.debug_pubnames) }
.debug_aranges 0 : { *(.debug_aranges) }
}