RTOS on ARM cortex-M platform -draft
- 1. RTOS - CM Neo Jou
- 2. IOT 技術同好會 Search : Ameba / IoT
- 3. AMEBA
- 4. CMSIS-DAP USB mbed disk / USB-Serial / Debug
- 5. TOPICS Cortex-M RTOS OS / Realtime HW design for RTOS Micro Kernel memory schedule IPC Future
- 6. ARM ARCH
- 7. ARM
- 8. ARM CORTEX
- 9. TOPICS Cortex-M RTOS OS / Realtime HW design for RTOS Micro Kernel memory schedule IPC Future
- 10. OS -> ＯＲ 運籌學 資源 => 有效運⽤ 兵⼒/糧草/時間...
- 11. 空間 Memory DOS - 640K arduino : Atmega328 : 2K SRAM / 32K flash Ameba : 512K internal
- 12. 時間 CPU 處理速度 cortem-M3/M4 1.25 DMIPS/MHz Ameba - 166MHz
- 13. 時空轉換 compiler toolchain 參數選擇 -Osize / -Otime 空間換取時間 e.g. loop unroll, 查表 : switch , … 時間換取空間 e.g. loop without unroll, compression
- 14. 資源 除了空間時間外, 還有什麼資源需要管理? Power consumption -> Zephyr 容易 porting CMSIS middleware (USB / TCPIP / .. ) ….
- 15. TRADE OFF 複雜的動態系統 external flash -> external RAM -> internal RAM -> cache ... task priority / critical path power consumption …
- 16. TOPICS Cortex-M RTOS OS / Realtime HW design for RTOS Micro Kernel memory schedule IPC
- 17. 即時 - REAL TIME deadline => priority -> renice -> preemptive Linux : RTOS ? kernel 非搶佔, user 權限⾼也無法搶佔 時間計算/限制機制 改良 重改 linux - PREEMPT_RT dual kernel - 替換底層 - Xenomai ( 底層⽤ Nucleus )
- 18. TOPICS Cortex-M RTOS OS / Realtime HW design for RTOS performance Micro Kernel memory schedule IPC Future
- 19. HW FOR RTOS MSP / PSP LR - branch (bx lr), EXC_RETURN auto push/pop stack privileged / handler - thread
- 20. REGISTERS
- 21. AAPCS Procedure Call Standard for ARM Architecture
- 22. HANDLER privileged thread / handler handler only have privileged mode
- 23. EXC_RETURN Exception : thread -> handler LR : EXC_RETURN
- 24. TOPICS Cortex-M RTOS OS / Realtime HW design for RTOS performance Micro Kernel memory schedule IPC Future
- 26. TEXT / DATA * Howard - HyperC OS * Linker script -http://njiot.blogspot.tw/2016/03/arduino-ameba-100-textdatabssheapstack.html
- 27. 動態管理 C: malloc / free sbrk() linker script
- 28. 動態管理 Windows: VirtualAlloc / HeapAlloc 非分⾴ / 分⾴ Linux: vmalloc / kmalloc : GFP_ATOMIC / GFP_KERNEL
- 29. 動態管理 cortex-M : no MMU , no virtual address 經濟 <-> 技術, RAM 價格曲線 MMU overhead / die size cost fragment / chunk / page / utilization
- 30. CACHE Ameba : cortex-m3 , no cache instruction / data barrier : ISB , DSB, DMB
- 31. TOPICS Cortex-M RTOS OS / Realtime Micro Kernel memory schedule IPC
- 35. 無線程排程-ISR 8-bit / 16-bit programming x86 BIOS/DOS INT
- 36. VECTOR TABLE
- 37. 線程排程 - TIMER - 1 One shot / period latency : 8 cycles auto push pop by HW Pros : easy, quick, less overhead
- 38. TICKER SCHEDULER ESP 8266 - yield() do back ground functions ; https://github.com/Toshik/TickerScheduler void setup(void) { … if (ts.add(0, 5000, task0, true)) { Serial.println("Tick task - task0 ok"); } if (ts.add(1, 2000, task1, true)) { Serial.println("Tick task - task1 ok"); } …. } void task0(void) { Serial.println("Task0"); } … void loop(void) { ts.update(); }
- 39. TICKER SCHEDULER
- 40. TICKER SCHEDULER ESP 8266 - yield() do back ground functions ; https://github.com/Toshik/TickerScheduler
- 42. TIMER CONS HW timer 有限 SW timer : 延遲 preemptive no reentrant context switch ? function execution -> starvation
- 44. 多⼯ - 3 ⼯作 Task 程式執⾏最⼩單位? Process =>Thread Unix -> Mach 第⼀代 micro kernel Mac OSX
- 45. THREAD
- 46. ARDUINO SCHEDULER zero, MKR1000 - cortex-m0+ , Due - cortex-m3 https://www.arduino.cc/en/Reference/Scheduler
- 51. ARDUINO SCHEDULER 和 mini-arm-os / RTX 很像 比 timer 優點 : TCB : Task control block 各⾃有 stack
- 53. SWITCH- SYSTICK
- 54. SWITCH - PENDSVC
- 55. CMSIS-RTOS Cortex Microcontroller Software Interface Standard
- 56. IDLE TASK busy waiting 耗電 WFI / WFE 中斷完成時直接休眠, 不回 Thread, 省下 stack push/ pop
- 57. TOPICS Cortex-M RTOS OS / Realtime Micro Kernel memory schedule IPC
- 58. IPC - 1 Inter Process Communication L4 kernel - 第⼆代微核⼼重點 f9-kernel: http://wiki.csie.ncku.edu.tw/ embedded/f9-kernel
- 59. SHARE MEMORY No thread safe flag interrupt write status thread polling
- 60. CRITICAL SECTION atomic spinlock / mutex / semaphore 差異?
- 62. IPC - ⼤訊息傳遞 message queue mail queue
- 64. 優先權錯逆 priority inversion realtime - deadline
- 65. 優先權錯逆 ⽕星探測計畫 http://wiki.csie.ncku.edu.tw/embedded/priority-inversion-on-Mars.pdf
- 66. 複雜 drivers wifi, usb, … network protocol TCP/IP SSL / TLS MQTT / HTTP ….
- 67. MBED OS LoRa : https://docs.mbed.com/docs/lora-with-mbed/en/latest/intro-to-lora/
- 69. WIN WDI DRIVER
- 70. 安全 資料安全 資訊隱藏與封裝 (C++) 資訊最⼩化公開原則 各⾃ stack 系統安全 : security boot 網路安全 : SSL/TLS
- 71. 安全- 硬體設計 Ameba Cortex-M3 : MPU -> mbed uvisor hardware crypto engine 加解密, 簽章 : AES / SHA-2 TrustZone : v8m : SAU stack limit
- 72. FUTURE Benchmark ARM mbed / Arduino CMSIS++ / mbed minar NUTTX : ardupilot / cortex-m4 Zephyr : Linux ⼩弟 dynamic linking / module loading hypervisor