我搞了十幾年嵌入式，才發現全局變量是這樣初始化的

int counter, accumulator = 0, limit_value = 1000000;unsigned char str_aa55[2] = {0xAA,0x55};unsigned int int_1122334455667788 = 0x11223344;unsigned int int_55667788 = 0x55667788;int bss_val;void main(void){? ? }

? -- Clear local RAM? mov ___ghs_ramstart, r6 ?-- start of local RAM? mov ___ghs_ramend, r7 ? ?-- end of local RAM? mov r0, r11:? st.dw ? r0, 0[r6]? addi ? ?8, r6, r6? cmp r7, r6? bl 1b? -- Jump to the HW initialisation function? jarl ?___lowinit, lp? -- Jump to the initialisation functions of the library? -- and from there to main()? jr __start

int counter, accumulator = 0, limit_value = 1000000;unsigned char str_aa55[2] = {0xAA,0x55};unsigned int ?int_1122334455667788 = 0x11223344;unsigned int ?int_55667788 = 0x55667788;int?bss_val;

? ? /* Init .data and .bss sections */? ? ldr ? ? r0,=init_data_bss? ? blx ? ? r0

void init_data_bss(void){    /*?......?*/? ? /* Data */? ? data_ram ? ? ? ?= (uint8_t *)__DATA_RAM;? ? data_rom ? ? ? ?= (uint8_t *)__DATA_ROM;? ? data_rom_end ? ?= (uint8_t *)__DATA_END;????/*?......?*/? ? /* BSS */? ? bss_start ? ? ? = (uint8_t *)__BSS_START;? ? bss_end ? ? ? ? = (uint8_t *)__BSS_END;? ? /* ...... */? ? ? ? /* Copy initialized data from ROM to RAM */? ? while (data_rom_end != data_rom)? ? {? ? ? ? *data_ram = *data_rom;? ? ? ? data_ram++;? ? ? ? data_rom++;? ? }? ? ? ? /* ...... */? ? /* Clear the zero-initialized data section */? ? while(bss_end != bss_start)? ? {? ? ? ? *bss_start = 0;? ? ? ? bss_start++;? ? }????/*?......?*/}

/* Specify the memory areas */MEMORY{? /* … */? /* SRAM_L */  m_data ? (RW) ?: ORIGIN = 0x1FFF8000, LENGTH = 0x00008000?m_data_2??(RW)??:?ORIGIN?=?0x20000000,?LENGTH?=?0x00007000
? /* … */  .data : AT(__DATA_ROM)? {? ? . = ALIGN(4);? ? __DATA_RAM = .;? ? __data_start__ = .; ? ? ?/* Create a global symbol at data start. */? ? *(.data) ? ? ? ? ? ? ? ? /* .data sections */? ? *(.data*) ? ? ? ? ? ? ? ?/* .data* sections */? ? . = ALIGN(4);? ? __data_end__ = .; ? ? ? ?/* Define a global symbol at data end. */? } > m_data
? __DATA_END = __DATA_ROM + (__data_end__ - __data_start__);? __CODE_ROM = __DATA_END; /* Symbol is used by code initialization. */

? /* Uninitialized data section. */? .bss :? {? ? /* This is used by the startup in order to initialize the .bss section. */? ? . = ALIGN(4);? ? __BSS_START = .;? ? __bss_start__ = .;? ? *(.bss)? ? *(.bss*)? ? *(COMMON)? ? . = ALIGN(4);? ? __bss_end__ = .;? ? __BSS_END = .;? } > m_data_2

.data ? ? ? ? ? 0x1fff8400 ? ? ?0x42c load address 0x000009cc? ? ? ? ? ? ? ? 0x1fff8400 ? ? ? ? ? ? ? ?. = ALIGN (0x4)? ? ? ? ? ? ? ? 0x1fff8400 ? ? ? ? ? ? ? ?__DATA_RAM = .? ? ? ? ? ? ? ? 0x1fff8400 ? ? ? ? ? ? ? ?__data_start__ = .?*(.data)?*(.data*)?.data.limit_value? ? ? ? ? ? ? ? 0x1fff8400 ? ? ? ?0x4 ./src/main.o? ? ? ? ? ? ? ? 0x1fff8400 ? ? ? ? ? ? ? ?limit_value?.data.str_aa55? ? ? ? ? ? ? ? 0x1fff8404 ? ? ? ?0x2 ./src/main.o? ? ? ? ? ? ? ? 0x1fff8404 ? ? ? ? ? ? ? ?str_aa55?*fill* ? ? ? ? 0x1fff8406 ? ? ? ?0x2 ?.data.int_11223344? ? ? ? ? ? ? ? 0x1fff8408 ? ? ? ?0x4 ./src/main.o? ? ? ? ? ? ? ? 0x1fff8408 ? ? ? ? ? ? ? ?int_11223344?.data.int_55667788? ? ? ? ? ? ? ? 0x1fff840c ? ? ? ?0x4 ./src/main.o? ? ? ? ? ? ? ? 0x1fff840c ? ? ? ? ? ? ? ?int_55667788

.bss ? ? ? ? ? ?0x20000000 ? ? ? 0x28? ? ? ? ? ? ? ? 0x20000000 ? ? ? ? ? ? ? ?. = ALIGN (0x4)? ? ? ? ? ? ? ? 0x20000000 ? ? ? ? ? ? ? ?__BSS_START = .? ? ? ? ? ? ? ? 0x20000000 ? ? ? ? ? ? ? ?__bss_start__ = .?*(.bss)?*(.bss*)?.bss.accumulator? ? ? ? ? ? ? ? 0x2000001c ? ? ? ?0x4 ./src/main.o? ? ? ? ? ? ? ? 0x2000001c ? ? ? ? ? ? ? ?accumulator?*(COMMON)?COMMON ? ? ? ? 0x20000020 ? ? ? ?0x8 ./src/main.o? ? ? ? ? ? ? ? 0x20000020 ? ? ? ? ? ? ? ?bss_val? ? ? ? ? ? ? ? 0x20000024 ? ? ? ? ? ? ? ?counter? ? ? ? ? ? ? ? 0x20000028 ? ? ? ? ? ? ? ?. = ALIGN (0x4)? ? ? ? ? ? ? ? 0x20000028 ? ? ? ? ? ? ? ?__bss_end__ = .????????????????0x20000028????????????????__BSS_END?=?.
????????????????0x000009cc????????????????__DATA_ROM?=?.

int limit_value = 1000000;unsigned char str_aa55[2] = {0xAA,0x55};unsigned int  int_1122334455667788 = 0x11223344;unsigned int  int_55667788 = 0x55667788;