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atc1441 / ATC_MiThermometer

Custom firmware for the Xiaomi Thermometer LYWSD03MMC and Telink Flasher via USB to Serial converter
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cstartup_8251 or cstartup_8258? #80

Closed pvvx closed 3 years ago

pvvx commented 3 years ago

AN_19011501-C5_Telink Kite BLE SDK Developer Handbook.pdf https://yadi.sk/i/FsMuapzANxT78Q image

cstartup_8258:

    ...
    tmov    r0, #0x13       @r0 = 0x13 SVC
    tmcsr   r0              @CPSR = r0
    tloadr  r0, DAT0 + 12   @r0 = __RAM_START_ADDR + __RAM_SIZE_MAX
    tmov    r13, r0         @r13 = r0 update SP under SVC mode
    ...

DAT0:
    .word   0x12                @IRQ    @0
    .word   0x13                @SVC    @4
    .word   (irq_stk + IRQ_STK_SIZE)
    .word   (**0x850000**)          @12  stack end

stack end -> 64k!

? https://github.com/atc1441/ATC_MiThermometer/blob/master/ATC_Thermometer/makefile#L45

ifeq ($(RETENTION_RAM_SIZE), 32KB)

LS_FLAGS := $(TEL_PATH)/components/boot/boot_32k_retn_8253_8258.link

else

LS_FLAGS := $(TEL_PATH)/components/boot/boot_16k_retn_8251_8253_8258.link

endif

SDK Ai-Thinker: BOOT_FLAG := -DMCU_STARTUP_8258_RET_16K https://github.com/Ai-Thinker-Open/Telink_825X_SDK/blob/master/make/boot.mk#L19

? BOOT_FLAG := -DMCU_STARTUP_8251_RET_16K https://github.com/Ai-Thinker-Open/Telink_825X_SDK/blob/master/components/boot/8251/cstartup_8251_RET_16K.S#L23

pvvx commented 3 years ago

I tested TLSR8253F512ET32 (Ai-Thinker BT-01..04 modules). https://docs.ai-thinker.com/blue_tooth All have 64 kilobytes of SRAM. Inside the crystal 8258 (?)

pvvx commented 3 years ago

ATC_MiThermometer uses a large 'Wasteful SRAM Area' and in firmware. Real end 'retention data' address 0x4400. Aligned(256). 0x4400..0x8000 = 'Wasteful SRAM Area' and data into Flash.

Reduce firmware size for flash and load speed. Set IC-cache start address 0x4400. cstartup_825x.zip

atc1441 commented 3 years ago

Thank you for that.

It is a bit above my head right now as i am fully into another topic but will ger back to it

pvvx commented 3 years ago

Building Reduced firmware size https://github.com/pvvx/ATC_MiThermometer