Freeing up Flash storage on ESP8266 board build

[gregspam]

Hi,

I'm in the process of squeezing out as much free flash space as possible on an ESP8266 for my frozen modules. This is what my current board definition looks like:

Code: Select all

boards/GENERIC_KOOJI_1M/manifest.py
::::::::::::::
include("$(PORT_DIR)/boards/manifest.py")
include("$(MPY_DIR)/extmod/uasyncio/manifest.py")
::::::::::::::
boards/GENERIC_KOOJI_1M/mpconfigboard.h
::::::::::::::
#define MICROPY_HW_BOARD_NAME "ESP module"
#define MICROPY_HW_MCU_NAME "ESP8266"

#define MICROPY_PERSISTENT_CODE_LOAD    (1)
#define MICROPY_EMIT_XTENSA             (1)
#define MICROPY_EMIT_INLINE_XTENSA      (1)

#define MICROPY_DEBUG_PRINTERS          (1)
#define MICROPY_ERROR_REPORTING         (MICROPY_ERROR_REPORTING_NORMAL)

#define MICROPY_READER_VFS              (MICROPY_VFS)
#define MICROPY_VFS                     (1)

#define MICROPY_PY_BUILTINS_SLICE_ATTRS (1)
#define MICROPY_PY_ALL_SPECIAL_METHODS  (1)
#define MICROPY_PY_IO_FILEIO            (1)
#define MICROPY_PY_SYS_STDIO_BUFFER     (1)
#define MICROPY_PY_UASYNCIO             (1)
#define MICROPY_PY_URE_SUB              (1)
#define MICROPY_PY_UCRYPTOLIB           (1)
#define MICROPY_PY_FRAMEBUF             (1)
::::::::::::::
boards/GENERIC_KOOJI_1M/mpconfigboard.mk
::::::::::::::
LD_FILES = boards/esp8266_1m.ld

MICROPY_PY_BTREE ?= 1
MICROPY_VFS_FAT ?= 1
MICROPY_VFS_LFS2 ?= 1

FROZEN_MANIFEST ?= $(BOARD_DIR)/manifest.py

I've commented out most of the frozen modules I don't need in the overall manifest:

Code: Select all

::::::::::::::
boards/manifest.py 
::::::::::::::
freeze("$(PORT_DIR)/modules")
#freeze("$(MPY_DIR)/tools", ("upip.py", "upip_utarfile.py"))
#freeze("$(MPY_DIR)/drivers/dht", "dht.py")
#freeze("$(MPY_DIR)/drivers/onewire")
#include("$(MPY_DIR)/extmod/webrepl/manifest.py")

This gives me a fully working build, but with about 7k space missing to add the totality of my frozen modules. What can I remove from here? I thought I could remove btree, but doing this resulted in the filesystem not working (could write files but they were empty) so I guess it is needed for that. I don't think I need SSL/TLS but haven't worked out how to successfully remove that from the build. Any suggestions on what I might be able to cull? My project uses uasyncio, mqtt_as and the machine.Pin and their dependencies, that's about it.

[Roberthh]

You can safely set BTREE to 0, which I do by default. It is not related to the file operations. If you have experienced that, there must be a different reason for that.

[rcolistete]

See this commit, "ESP8266 1MB made compatible with ulab module", where 'ports/esp8266/boards/esp8266_1m.ld' is changed, so
- firmware (irom0) space is increased to 618k (was 572k);
- filesystem is reduced to 350k (was 396k).
You can obviously reduce the file system with diferent values.