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memprobe

Online ELF analyzer for embedded firmware.

Drop an ELF file. Flash and RAM usage broken down by symbol, section, and source file. Bloat flagged with the exact fix.

Analyze for free Save & track builds

No account needed to analyze · Binaries never stored

nm · what you have now

00084000 r _ZL17VL53L5CX_FIRMWARE 00008000 b farZonePx 00007260 b _ZL4grid 00002fbc t _svfprintf_r 00002fd0 t _vfprintf_r

memprobe · what you get

_ZL17VL53L5CX_FIRMWARE84 KB.flash.rodata · SparkFun_VL53L5CX/src

farZonePx32 KB.dram0.bss · include/base/grid.h:28

_ZL4grid29 KB.dram0.bss · src/screens/map3d_screen.cpp:32

_svfprintf_r12 KB.flash.text · libc/stdio/local.h:154

A real ESP32 firmware analysis.

Every tab below is live, straight from the binary.

memprobe.dev/app

memprobe

Analysis

firmware.elf

Flash

893.7 KB

~194.7 KB OTA

RAM

115.6 KB

Sections

156

4,013 symbols

Warnings

Binary info

Architecture

Xtensa

Chip family

ESP32 (Xtensa LX6/LX7)

Bitness

32-bit

ELF type

Executable

Endianness

little-endian

OS/ABI

ELFOSABI_SYSV

Entry point

0x40377734

ELF flags

0x300

Compiler

GCC: (crosstool-NG esp-2021r2-patch5) 8.4.0

OTA estimate

~194.7 KB compressed (65% of 299.5 KB raw) · zlib

Load segments (PT_LOAD)

VAddr	PAddr	File size	Mem size	Flags
0x3c000020	0x3c000020	509.4 KB	509.4 KB	rw-
0x3fc88000	0x3fc88000	70.0 KB	169.8 KB	rw-
0x40374000	0x40374000	70.2 KB	70.2 KB	rwx
0x42000020	0x42000020	299.5 KB	299.5 KB	r-x
0x50000000	0x50000000	0 B	16 B	rw-

Sections

Name Size %

.flash_rodata_dummy

Read-only constant data.

320.0 KB

20.2%

.flash.text

Executable code stored in flash (ESP32)

299.5 KB

18.9%

.xt.prop

Xtensa property table. Toolchain metadata.

266.4 KB

16.8%

.flash.rodata

Read-only data in flash (ESP32)

189.1 KB

11.9%

.dram0.bss

Uninitialized data in DRAM (ESP32)

99.8 KB

6.3%

Show all 156 sections

Memory treemap

firmware

.flash_rodata

320.0 KB

.flash.text

290.7 KB

.xt.prop

266.4 KB

.dram0.bss

100.3 KB

.str…

132.2 KB

.symtab

118.0 KB

.fla…

118.3 KB

.ira…

59.6 KB

.dra…

54.2 KB

Symbol table 4,013 symbols

Demangle C++

Name	Size	Section	Source
_ZL17VL53L5CX_FIRMWARE	86,016	.flash.rodata	…/SparkFun_VL53L5CX_Arduino_Library/src
farZonePx	32,768	.dram0.bss	include/base/grid.h:28
_ZL4grid	29,280	.dram0.bss	src/screens/map3d_screen.cpp:32
_ZL6s_path	18,000	.dram0.bss	src/screens/tracker_screen.cpp:15
_vfprintf_r	12,250	.flash.text	…/libc/include/stdio.h:503
_svfprintf_r	11,979	.flash.text	…/libc/stdio/local.h:154
_vfiprintf_r	8,354	.flash.text	…/libc/include/stdio.h:499

Call graph

Warnings

C++ exceptions linked (__cxa_throw). Unwind tables add flash overhead.

RTTI enabled: 5 typeinfo record(s), 56 bytes.

assert() linked with file/line strings (__assert_func). Each call site embeds __FILE__, __func__, and the expression in flash.

Stack canaries enabled (__stack_chk_fail). Each protected frame costs one extra stack word plus entry/exit checks.

'_ZL17VL53L5CX_FIRMWARE' is 84.0 KB in .flash.rodata.

Binary Insights Pro

Savings

881 B

recoverable flash

INFO 881 B 9 symbol(s) in multiple translation units. Link with -flto or --icf=safe to deduplicate

INFO 4.1 KB alignment padding between symbols

WARN C++ exceptions linked. Build with -fno-exceptions to remove unwind tables

File contributors

Source file Flash RAM

…/SparkFun_VL53L5CX_Arduino_Library/src/vl53l5cx_buff…

85.7 KB

lib/TFT_eSPI/TFT_eSPI.cpp

10.2 KB

src/managers/tab_manager.cpp

9.6 KB

1.2 KB

Dead code Pro

Reachability

A function is listed only when no caller is reachable from the entry point, interrupt vectors, or any stored function pointer. 312 address-taken function(s) were kept on that basis.

100.1 KB

reclaimable

800

unreferenced

1,694 / 2,494

reachable

312

address-taken (kept)

Unreferenced functions

Function	Size	Section	Source
esp_eth_ioctl	2.4 KB	.flash.text	…/esp_eth/src/esp_eth.c
mbedtls_ssl_setup	1.8 KB	.flash.text	…/mbedtls/library/ssl_tls.c
vl53l5cx_dci_write_data	1.3 KB	.flash.text	…/vl53l5cx_api.c
ledc_set_fade_with_time	872 B	.flash.text	…/driver/ledc.c
spi_bus_remove_device	560 B	.flash.text	…/driver/spi_master.c

How to read this

Functions reached only through a computed pointer that never appears as a stored address word (such as relative jump tables) cannot be seen statically and are NOT listed here.
Candidates may already be dropped by the linker when --gc-sections is enabled; this report is most useful when it is not.
Verify before removing: confirm each symbol is unused in your own sources.

Stack usage Pro

6,816 B

worst-case stack fully bounded

frame source: .su (GCC -fstack-usage)

1,902 frames over 2,494 functions

Worst-case stack is the deepest sum of frame sizes along any call chain. It is a lower bound: paths through recursion, indirect calls, or dynamic allocation are flagged and never silently dropped.

Deepest call chain

app_main→ display_task→ lvgl_render→ decode_png→ tjpgd_decomp

Per entry point

Entry point	Worst-case depth	Bounded	Note
app_main	6,816 B	bounded	-
wifi_task	3,072 B	bounded	-
ipc_task	2,304 B	bounded	-
tiT	1,984 B	lower bound	makes an indirect call (callees unknown)
esp_timer	1,536 B	bounded	-

Also in your terminal and CI.

The same analysis from the command line, with a budget gate for CI.

Built for CI

The GitHub Action posts a size report on every pull request: flash/RAM change against your project's baseline, the symbols that grew, and a failed check when a budget is blown. One build, no base branch rebuild.

In your workflow

- uses: memprobe-dev/memprobe-action@v1 with: file: build/firmware.elf project: my-firmware api-key: ${{ secrets.MEMPROBE_API_KEY }}

Your binary never leaves your machine. Only section and symbol metadata is sent, the same data readelf and nm print.

Set up the GitHub Action, or see the CLI reference for any other CI.

1. Install

$pip install memprobe

2. Connect your account

$memprobe config set --key mp_live_xxxxxxxx

3. Analyze or gate a build

$memprobe analyze build/firmware.elf

$memprobe check build/firmware.elf # CI gate

From ELF to answers in seconds.

Drop your ELF file

Drag in the output from GCC or Clang: an ELF or AXF file. No install needed. Files are processed on the server and not stored after the request completes.

See what's in your binary

Every section sized and colored. Every symbol (demangled if C++) traced back to its source file and line via DWARF. Compiler bloat flagged with the specific flag to fix it, like -fno-exceptions or --icf=safe.

Track builds, catch regressions

Save builds to a project and set a flash or RAM budget. When a commit pushes you over, you'll see which symbols grew or appeared. Catch it on your machine, not during code review.

Works with your toolchain.

memprobe reads ELF, the format every embedded toolchain produces. If your build makes a .elf or .axf, it works.

Binary formats

.elf (ELF executables) .axf (Keil / Arm) 32 and 64-bit Little and big endian Stripped ELFs (basic report)

Toolchains

GCC (arm-none-eabi) Clang / LLVM ESP-IDF Zephyr PlatformIO Keil MDK (.axf) IAR (ELF output) Rust (cargo)

Architectures

ARM Cortex-M ARM64 RISC-V Xtensa (ESP32) AVR MIPS PowerPC x86

Read from the binary

Sections & segments Symbols, C++ demangled DWARF source mapping Call graph Chip detection (STM32, nRF, ESP32)

No SDK plugins or build changes. Point it at the binary your build already makes. Raw .bin/.hex images and linker .map files aren't supported: the analysis reads the ELF itself.

Everything nm and size don't tell you.

Symbol → source line

DWARF debug info maps every symbol back to the exact file and line that produced it. No manual cross-referencing between nm output and your source tree.

Bloat with specific fixes

Float printf pulling in 12 KB of libc? C++ exceptions adding unwind tables? Each warning names the symbol, the size cost, and the exact compiler flag to remove it.

Build-to-build diffs

Compare any two builds side by side. See which symbols grew, shrank, appeared, or were removed. Useful for reviewing a PR's binary footprint before it merges.

Flash and RAM budgets

Set a hard limit per project. Each saved build is measured against it. You see the delta immediately and can spot the commit that pushed you over.

C++ and library aware

Mangled names are demangled. Symbols from known libraries (mbedTLS, FreeRTOS, lwIP, Arduino cores) are grouped so you can see how much each dependency costs.

Drop a binary. Get answers.

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