I tried to test RT-STM32L476RG-NUCLEO64 demo and to load it with blackmagic Probe but it failed.
Turns out that the issue is a FLASH memory align issue. As per ST's RM0351, writes should be 8-bytes aligned, but ChibiOS's linker aligns the different sections to 4 bytes. In the end, it causes some overwrites and FLASH locks down.
I dirty-fixed the issue with the modifications below, but would it be possible to make something cleaner?
Like inlcuding all sections into a bigger one "flash" and have only one section loaded (that would concatenate all sections taking care of align issues) ?
I understand it's probably a BMP limitation, but maybe other debuggers may have the issue too?
FYI : link to the original issue subject
Code: Select all
diff --git a/os/common/startup/ARMCMx/compilers/GCC/ld/rules_code.ld b/os/common/startup/ARMCMx/compilers/GCC/ld/rules_code.ld
index f61fe2d..41e8beb 100644
--- a/os/common/startup/ARMCMx/compilers/GCC/ld/rules_code.ld
+++ b/os/common/startup/ARMCMx/compilers/GCC/ld/rules_code.ld
@@ -44,7 +44,7 @@ SECTIONS
*(.gcc*)
} > TEXT_FLASH AT > TEXT_FLASH_LMA
- .rodata : ALIGN(4)
+ .rodata : ALIGN(8)
{
. = ALIGN(4);
__rodata_base__ = .;
diff --git a/os/common/startup/ARMCMx/compilers/GCC/ld/rules_data.ld b/os/common/startup/ARMCMx/compilers/GCC/ld/rules_data.ld
index c531015..40a4159 100644
--- a/os/common/startup/ARMCMx/compilers/GCC/ld/rules_data.ld
+++ b/os/common/startup/ARMCMx/compilers/GCC/ld/rules_data.ld
@@ -43,7 +43,7 @@ ENTRY(Reset_Handler)
SECTIONS
{
- .data : ALIGN(4)
+ .data : ALIGN(8)
{
. = ALIGN(4);
PROVIDE(_textdata = LOADADDR(.data));
