Come usare
- Copia il comando e controlla il pacchetto prima di installarlo nel tuo ambiente agente.
- Controlla strumenti, credenziali e ambienti richiesti nel documento originale.
- Descrivi input e risultato desiderato; confronta l’output con le fonti.
npx skills add https://github.com/mohitmishra786/low-level-dev-skills --skill resource-optimization-lowendPrima di iniziare
- L’installazione non include abbonamenti, quote API o accesso ai file.
- Stelle e installazioni indicano attività, non un test indipendente di qualità o sicurezza.
Documento Skill originale
Contenuto dal repository con titoli, esempi, codice, tabelle, link e immagini preservati.
Resource Optimization (Low-End Systems)
Purpose
Guide agents through flash and RAM optimization on constrained devices: compiler size flags, linker map analysis, stack usage measurement, dead code elimination, and size-vs-speed tradeoffs — for bare-metal and small RTOS images.
When to Use
- Firmware exceeds flash budget
- Stack overflow in production only
- Choosing
-Osvs-O2on MCU - Finding unexpected
.rodataor.bssgrowth
Workflow
1. Size measurement toolchain
bash
arm-none-eabi-size -A firmware.elf
arm-none-eabi-objdump -h firmware.elf
nm --size-sort -S firmware.elf | tail -202. Linker map file
ld
/* linker.ld */
OUTPUT_FORMAT("elf32-littlearm")
ENTRY(Reset_Handler)
SECTIONS
{
/* ... */
}
/* Generate map */
/* gcc ... -Wl,-Map=firmware.map */bash
grep -E '\.text|\.rodata|\.data|\.bss' firmware.map | headIdentify largest symbols and unexpected library pull-in.
3. Compiler flags
| Flag | Effect |
|---|---|
-Os | Size-first optimization |
-ffunction-sections -fdata-sections | Per-symbol sections |
-Wl,--gc-sections | Drop unused sections |
-flto | Cross-TU dead code elimination |
-specs=nano.specs | Smaller newlib (GCC ARM) |
makefile
CFLAGS += -Os -ffunction-sections -fdata-sections
LDFLAGS += -Wl,--gc-sections -Wl,--print-memory-usage4. Stack analysis
bash
# Static (if built with -fstack-usage)
find . -name '*.su' -exec cat {} \;
# Linker stack symbol
grep _estack firmware.mapRuntime: fill stack with pattern (0xDEADBEEF), run tests, scan high-water mark. FreeRTOS: uxTaskGetStackHighWaterMark.
5. RAM categories
| Section | Tactic |
|---|---|
.bss | Shrink buffers; pool allocators |
.data | Move const to flash (const → .rodata) |
| Heap | Avoid malloc; fixed pools |
| Stack | Reduce nesting; smaller ISR stacks |
6. Size vs speed decision
Hot path in ISR or 1 kHz loop?
├── Yes → -O2 for that file (#pragma GCC optimize)
└── No → -Os globally7. Agent usage
/resource-optimization-lowend Find top 10 flash consumers in firmware.map and suggest -gc-sections fixesCommon Problems
| Symptom | Cause | Fix |
|---|---|---|
| printf pulls 20+ KB | Full newlib printf | _write retarget; tiny printf |
--gc-sections broke IRQ | Section collected | KEEP() in linker script |
| Stack overflow late | Deep call + IRQ nest | Measure HW stack; increase _estack |
| RAM zero but big ELF | .data not loaded | Check VMA/LMA |
| LTO link fail | Mixed compiler versions | Same GCC for all objects |
Related Skills
skills/embedded/linker-scripts— MEMORY/Sections layoutskills/baremetal/baremetal-startup— stack symbolskills/baremetal/low-power-embedded— RAM retentionskills/compilers/gcc— optimization flagsskills/rust/rust-no-std— embedded Rust size patterns
