- fix the value of SOC_ROM_STACK_START in soc.h
- Update the memory usage of ROM bootloader appendix in bootloader.ld
- Update the soc_memory_regions table to minimize the number of regions
created after the startup stack is added back as a heap.
Adding prop and lit sections to the ELF will let the debugger and the disassembler
have more info about data bytes present in the middle of the Xtensa
instructions, usually used for padding.
The change fixes thread-local-storage size by removing .srodata section
from it. It initially was included in TLS section by mistake.
The issue was found when stack size increased after building applications
with GCC-11.1 compiler. Stack size became bigger because some new data
appeared in .srodata. See more details here:
adce62f53d
The previously used splits between memory allocated for ROM code,
2nd stage bootloader and the app were somewhat safe and conservative.
This resulted in some space being unavailable for static allocation
in the app.
This commit increases the space available for static allocation to the
maximum possible amount.
1. Some of the ROM code static allocation is only used in UART/USB/SPI
download modes. This region ("shared buffers") has been placed at
the lower end of ROM memory area, to be reusable in flash boot
mode. The 2nd stage bootloader linker script is modified to "pack"
all sections exactly up to the end but with roughly 8K margin between
startup stacks.
2. Instead of calculating the sections placement and hardcoding the
addresses in the LD script again, rewrite it to calculate the
start address of each memory region automatically based on the
logic above.
3. Adjust the app memory layout (SRAM_IRAM_END) accordingly,
increasing the space available for static allocation.
Overall these changes increase the space available for static
allocation by about 78kB.
The downside of these changes is that the 2nd stage bootloader .data
segment is now directly adjacent to the startup stack on the PRO CPU.
Previously, there was effectively about 78kB of extra stack space for
the PRO CPU, before the stack would run into the data segment.
Add the possibility to have user bootloader components. This is performed
from an application/project, by creating bootloader components. To do so,
it is required to create a `bootloader_component` directory containing
the custom modules to be compiled with the bootloader.
Thanks to this, two solutions are available to override the bootloader now:
- Using hooks within a user bootloader component
- Using a user defined `main` bootloader component to totally override the
old implementation
Please check the two new examples in `examples/custom_bootloader`
* Closes https://github.com/espressif/esp-idf/issues/7043
The CPU might prefetch instructions, which means it in some cases
will try to fetch instruction located after the last instruction in
flash.text.
Add dummy bytes to ensure fetching these wont result in an error,
e.g. MMU exceptions
