内存映射
单片机是内存映射控件，应用程序通过读写对应地址完成对外设的控制。
以STM32为例， 程序存储器、数据存储器、寄存器和输入输出端口被组织在同一个4GB的线性地址空间内。
地址范围为0x0000 0000至0xFFFF FFFF。
image-20240118102645673.png
从内存映射布局可以看到：
- 片上Flash被映射到0x0800 0000-0x0801 FFFF的地址空间，通过读写这个地址空间，可以对Flash进行读写。
- 运行内存RAM被映射到0x2000 0000开始的一片区域。
更进一步，在MDK下，通过生成的map文件，可以直观地看到FLash和RAM更加细节的布局。
FLash布局
Memory Map of the image
Image Entry point : 0x080000b9
Load Region LR_IROM1 (Base: 0x08000000, Size: 0x000061d8, Max: 0x00020000, ABSOLUTE)
Execution Region ER_IROM1 (Exec base: 0x08000000, Load base: 0x08000000, Size: 0x00006120, Max: 0x00020000, ABSOLUTE)
Exec Addr Load Addr Size Type Attr Idx E Section Name Object
0x08000000 0x08000000 0x000000b8 Data RO 1193 RESET startup_stm32g070xx.o
0x080000b8 0x080000b8 0x00000000 Code RO 3003 * .ARM.Collect$$$$00000000 mc_p.l(entry.o)
0x080000b8 0x080000b8 0x00000004 Code RO 3315 .ARM.Collect$$$$00000001 mc_p.l(entry2.o)
0x080000bc 0x080000bc 0x00000004 Code RO 3318 .ARM.Collect$$$$00000004 mc_p.l(entry5.o)
0x080000c0 0x080000c0 0x00000000 Code RO 3320 .ARM.Collect$$$$00000008 mc_p.l(entry7b.o)
0x080000c0 0x080000c0 0x00000000 Code RO 3322 .ARM.Collect$$$$0000000A mc_p.l(entry8b.o)
0x080000c0 0x080000c0 0x00000008 Code RO 3323 .ARM.Collect$$$$0000000B mc_p.l(entry9a.o)
0x080000c8 0x080000c8 0x00000000 Code RO 3325 .ARM.Collect$$$$0000000D mc_p.l(entry10a.o)
0x080000c8 0x080000c8 0x00000000 Code RO 3327 .ARM.Collect$$$$0000000F mc_p.l(entry11a.o)
0x080000c8 0x080000c8 0x00000004 Code RO 3316 .ARM.Collect$$$$00002712 mc_p.l(entry2.o)
0x080000cc 0x080000cc 0x0000001c Code RO 1194 .text startup_stm32g070xx.o
0x080000e8 0x080000e8 0x0000002c Code RO 3006 .text mc_p.l(uidiv.o)
0x08000114 0x08000114 0x00000028 Code RO 3008 .text mc_p.l(idiv.o)
0x0800013c 0x0800013c 0x00000024 Code RO 3010 .text mc_p.l(memseta.o)
0x08000160 0x08000160 0x0000000e Code RO 3012 .text mc_p.l(strlen.o)
0x0800016e 0x0800016e 0x0000001c Code RO 3014 .text mc_p.l(strcmp.o)
0x0800018a 0x0800018a 0x0000001e Code RO 3016 .text mc_p.l(strncmp.o)
0x080001a8 0x080001a8 0x0000007a Code RO 3307 .text mf_p.l(fmul.o)
0x08000222 0x08000222 0x0000007c Code RO 3309 .text mf_p.l(fdiv.o)
0x0800029e 0x0800029e 0x00000016 Code RO 3311 .text mf_p.l(fflti.o)
0x080002b4 0x080002b4 0x0000000e Code RO 3313 .text mf_p.l(ffltui.o)
0x080002c2 0x080002c2 0x00000060 Code RO 3330 .text mc_p.l(uldiv.o)
0x08000322 0x08000322 0x00000000 Code RO 3338 .text mc_p.l(iusefp.o)
0x08000322 0x08000322 0x00000082 Code RO 3339 .text mf_p.l(fepilogue.o)
0x080003a4 0x080003a4 0x00000164 Code RO 3341 .text mf_p.l(dadd.o)
0x08000508 0x08000508 0x000000d0 Code RO 3343 .text mf_p.l(dmul.o)
0x080005d8 0x080005d8 0x000000f0 Code RO 3345 .text mf_p.l(ddiv.o)
0x080006c8 0x080006c8 0x00000040 Code RO 3347 .text mf_p.l(dfixul.o)
0x08000708 0x08000708 0x00000028 Code RO 3349 .text mf_p.l(cdrcmple.o)
0x08000730 0x08000730 0x00000024 Code RO 3351 .text mc_p.l(init.o)
0x08000754 0x08000754 0x00000020 Code RO 3353 .text mc_p.l(llshl.o)
0x08000774 0x08000774 0x00000022 Code RO 3355 .text mc_p.l(llushr.o)
0x08000796 0x08000796 0x00000026 Code RO 3357 .text mc_p.l(llsshr.o)
0x080007bc 0x080007bc 0x000000be Code RO 3359 .text mf_p.l(depilogue.o)
0x0800087a 0x0800087a 0x00000002 PAD
0x0800087c 0x0800087c 0x00000098 Code RO 2859 i.HAL_DMA_Abort stm32g0xx_hal_dma.o
0x08000914 0x08000914 0x00000094 Code RO 2860 i.HAL_DMA_Abort_IT stm32g0xx_hal_dma.o
0x080009a8 0x080009a8 0x000001d8 Code RO 1868 i.HAL_GPIO_Init stm32g0xx_hal_gpio.o
0x08000b80 0x08000b80 0x00000012 Code RO 1870 i.HAL_GPIO_ReadPin stm32g0xx_hal_gpio.o
0x08000b92 0x08000b92 0x0000000c Code RO 1872 i.HAL_GPIO_WritePin stm32g0xx_hal_gpio.o
0x08000b9e 0x08000b9e 0x00000002 PAD
0x08000ba0 0x08000ba0 0x0000000c Code RO 1209 i.HAL_GetTick stm32g0xx_hal.o
0x08000bac 0x08000bac 0x0000002c Code RO 1216 i.HAL_Init stm32g0xx_hal.o
0x08000bd8 0x08000bd8 0x00000060 Code RO 1217 i.HAL_InitTick stm32g0xx_hal.o
0x08000c38 0x08000c38 0x00000002 Code RO 1219 i.HAL_MspInit stm32g0xx_hal.o
0x08000c3a 0x08000c3a 0x00000002 PAD
0x08000c3c 0x08000c3c 0x0000003c Code RO 1393 i.HAL_NVIC_DisableIRQ stm32g0xx_hal_cortex.o
0x08000c78 0x08000c78 0x00000024 Code RO 1394 i.HAL_NVIC_EnableIRQ stm32g0xx_hal_cortex.o
0x08000c9c 0x08000c9c 0x00000012 Code RO 1398 i.HAL_NVIC_SetPriority stm32g0xx_hal_cortex.o
0x08000cae 0x08000cae 0x00000002 PAD
0x08000cb0 0x08000cb0 0x00000058 Code RO 1752 i.HAL_PWREx_ControlVoltageScaling stm32g0xx_hal_pwr_ex.o
0x08000d08 0x08000d08 0x000001d4 Code RO 1504 i.HAL_RCC_ClockConfig stm32g0xx_hal_rcc.o
0x08000edc 0x08000edc 0x0000000c Code RO 1510 i.HAL_RCC_GetHCLKFreq stm32g0xx_hal_rcc.o
0x08000ee8 0x08000ee8 0x00000028 Code RO 1512 i.HAL_RCC_GetPCLK1Freq stm32g0xx_hal_rcc.o
0x08000f10 0x08000f10 0x000000e4 Code RO 1514 i.HAL_RCC_GetSysClockFreq stm32g0xx_hal_rcc.o
0x08000ff4 0x08000ff4 0x000005ac Code RO 1518 i.HAL_RCC_OscConfig stm32g0xx_hal_rcc.o
0x080015a0 0x080015a0 0x00000038 Code RO 1402 i.HAL_SYSTICK_Config stm32g0xx_hal_cortex.o
0x080015d8 0x080015d8 0x00000002 Code RO 1943 i.HAL_UARTEx_RxEventCallback stm32g0xx_hal_uart.o
0x080015da 0x080015da 0x00000002 Code RO 2375 i.HAL_UARTEx_RxFifoFullCallback stm32g0xx_hal_uart_ex.o
0x080015dc 0x080015dc 0x00000002 Code RO 2379 i.HAL_UARTEx_TxFifoEmptyCallback stm32g0xx_hal_uart_ex.o
0x080015de 0x080015de 0x00000002 Code RO 2380 i.HAL_UARTEx_WakeupCallback stm32g0xx_hal_uart_ex.o
0x080015e0 0x080015e0 0x00000002 Code RO 1959 i.HAL_UART_ErrorCallback stm32g0xx_hal_uart.o
0x080015e2 0x080015e2 0x00000002 PAD
0x080015e4 0x080015e4 0x0000042e Code RO 1962 i.HAL_UART_IRQHandler stm32g0xx_hal_uart.o
0x08001a12 0x08001a12 0x00000082 Code RO 1963 i.HAL_UART_Init stm32g0xx_hal_uart.o
0x08001a94 0x08001a94 0x00000090 Code RO 350 i.HAL_UART_MspInit elab_uart_debug.o
0x08001b24 0x08001b24 0x00000092 Code RO 1968 i.HAL_UART_Receive_IT stm32g0xx_hal_uart.o
0x08001bb6 0x08001bb6 0x00000002 PAD
0x08001bb8 0x08001bb8 0x00000034 Code RO 351 i.HAL_UART_RxCpltCallback elab_uart_debug.o
0x08001bec 0x08001bec 0x00000118 Code RO 1974 i.HAL_UART_Transmit_IT stm32g0xx_hal_uart.o
0x08001d04 0x08001d04 0x00000040 Code RO 352 i.HAL_UART_TxCpltCallback elab_uart_debug.o
0x08001d44 0x08001d44 0x00000004 Code RO 1125 i.HardFault_Handler stm32g0xx_it.o
0x08001d48 0x08001d48 0x00000004 Code RO 1126 i.NMI_Handler stm32g0xx_it.o
0x08001d4c 0x08001d4c 0x00000010 Code RO 328 i.SysTick_Handler elab_time.o
0x08001d5c 0x08001d5c 0x00000002 Code RO 1161 i.SystemInit system_stm32g0xx.o
0x08001d5e 0x08001d5e 0x000000f0 Code RO 1977 i.UART_AdvFeatureConfig stm32g0xx_hal_uart.o
0x08001e4e 0x08001e4e 0x00000002 PAD
0x08001e50 0x08001e50 0x00000078 Code RO 1978 i.UART_CheckIdleState stm32g0xx_hal_uart.o
0x08001ec8 0x08001ec8 0x00000018 Code RO 1979 i.UART_DMAAbortOnError stm32g0xx_hal_uart.o
0x08001ee0 0x08001ee0 0x00000084 Code RO 1989 i.UART_EndRxTransfer stm32g0xx_hal_uart.o
0x08001f64 0x08001f64 0x00000038 Code RO 1990 i.UART_EndTransmit_IT stm32g0xx_hal_uart.o
0x08001f9c 0x08001f9c 0x000000e8 Code RO 1992 i.UART_RxISR_16BIT stm32g0xx_hal_uart.o
0x08002084 0x08002084 0x00000210 Code RO 1993 i.UART_RxISR_16BIT_FIFOEN stm32g0xx_hal_uart.o
0x08002294 0x08002294 0x000000e8 Code RO 1994 i.UART_RxISR_8BIT stm32g0xx_hal_uart.o
0x0800237c 0x0800237c 0x0000020c Code RO 1995 i.UART_RxISR_8BIT_FIFOEN stm32g0xx_hal_uart.o
0x08002588 0x08002588 0x00000230 Code RO 1996 i.UART_SetConfig stm32g0xx_hal_uart.o
0x080027b8 0x080027b8 0x000001b4 Code RO 1998 i.UART_Start_Receive_IT stm32g0xx_hal_uart.o
0x0800296c 0x0800296c 0x00000078 Code RO 1999 i.UART_TxISR_16BIT stm32g0xx_hal_uart.o
0x080029e4 0x080029e4 0x00000098 Code RO 2000 i.UART_TxISR_16BIT_FIFOEN stm32g0xx_hal_uart.o
0x08002a7c 0x08002a7c 0x00000074 Code RO 2001 i.UART_TxISR_8BIT stm32g0xx_hal_uart.o
0x08002af0 0x08002af0 0x00000094 Code RO 2002 i.UART_TxISR_8BIT_FIFOEN stm32g0xx_hal_uart.o
0x08002b84 0x08002b84 0x00000120 Code RO 2003 i.UART_WaitOnFlagUntilTimeout stm32g0xx_hal_uart.o
0x08002ca4 0x08002ca4 0x00000010 Code RO 1127 i.USART3_4_IRQHandler stm32g0xx_it.o
0x08002cb4 0x08002cb4 0x00000020 Code RO 3251 i.__0printf mc_p.l(printfa.o)
0x08002cd4 0x08002cd4 0x00000028 Code RO 3253 i.__0sprintf mc_p.l(printfa.o)
0x08002cfc 0x08002cfc 0x0000002e Code RO 3361 i.__ARM_clz mf_p.l(depilogue.o)
0x08002d2a 0x08002d2a 0x0000001c Code RO 1011 i.__ARM_common_switch8 shell.o
0x08002d46 0x08002d46 0x00000002 PAD
0x08002d48 0x08002d48 0x00000078 Code RO 1404 i.__NVIC_SetPriority stm32g0xx_hal_cortex.o
0x08002dc0 0x08002dc0 0x00000006 Code RO 2004 i.__get_PRIMASK stm32g0xx_hal_uart.o
0x08002dc6 0x08002dc6 0x0000000e Code RO 3365 i.__scatterload_copy mc_p.l(handlers.o)
0x08002dd4 0x08002dd4 0x00000002 Code RO 3366 i.__scatterload_null mc_p.l(handlers.o)
0x08002dd6 0x08002dd6 0x0000000e Code RO 3367 i.__scatterload_zeroinit mc_p.l(handlers.o)
0x08002de4 0x08002de4 0x00000006 Code RO 2005 i.__set_PRIMASK stm32g0xx_hal_uart.o
0x08002dea 0x08002dea 0x00000002 PAD
0x08002dec 0x08002dec 0x0000008c Code RO 586 i._assert elab_assert.o
0x08002e78 0x08002e78 0x00000060 Code RO 38 i._check_pin_name_valid eio_pin.o
0x08002ed8 0x08002ed8 0x00000006 Code RO 207 i._error_handler bsp.o
0x08002ede 0x08002ede 0x00000002 PAD
0x08002ee0 0x08002ee0 0x00000174 Code RO 3258 i._fp_digits mc_p.l(printfa.o)
0x08003054 0x08003054 0x0000009c Code RO 475 i._get_init_export_table elab_export.o
0x080030f0 0x080030f0 0x000000cc Code RO 476 i._get_poll_export_table elab_export.o
0x080031bc 0x080031bc 0x00000078 Code RO 477 i._init_func_execute elab_export.o
0x08003234 0x08003234 0x00000088 Code RO 478 i._poll_func_execute elab_export.o
0x080032bc 0x080032bc 0x000006ec Code RO 3259 i._printf_core mc_p.l(printfa.o)
0x080039a8 0x080039a8 0x00000020 Code RO 3260 i._printf_post_padding mc_p.l(printfa.o)
0x080039c8 0x080039c8 0x0000002c Code RO 3261 i._printf_pre_padding mc_p.l(printfa.o)
0x080039f4 0x080039f4 0x0000000a Code RO 3263 i._sputc mc_p.l(printfa.o)
0x080039fe 0x080039fe 0x00000076 Code RO 208 i._system_clock_config bsp.o
0x08003a74 0x08003a74 0x000000e0 Code RO 39 i._translate_pin_name eio_pin.o
0x08003b54 0x08003b54 0x0000000c Code RO 209 i.bsp_init bsp.o
0x08003b60 0x08003b60 0x00000044 Code RO 40 i.eio_pin_get_status eio_pin.o
0x08003ba4 0x08003ba4 0x000000ec Code RO 41 i.eio_pin_init eio_pin.o
0x08003c90 0x08003c90 0x00000098 Code RO 42 i.eio_pin_set_status eio_pin.o
0x08003d28 0x08003d28 0x00000004 Code RO 587 i.elab_assert_func elab_assert.o
0x08003d2c 0x08003d2c 0x00000070 Code RO 354 i.elab_debug_uart_init elab_uart_debug.o
0x08003d9c 0x08003d9c 0x00000028 Code RO 355 i.elab_debug_uart_receive elab_uart_debug.o
0x08003dc4 0x08003dc4 0x00000060 Code RO 356 i.elab_debug_uart_send elab_uart_debug.o
0x08003e24 0x08003e24 0x0000002c Code RO 479 i.elab_run elab_export.o
0x08003e50 0x08003e50 0x0000000c Code RO 329 i.elab_time_ms elab_time.o
0x08003e5c 0x08003e5c 0x0000000e Code RO 414 i.elib_queue_init elib_queue.o
0x08003e6a 0x08003e6a 0x00000012 Code RO 415 i.elib_queue_is_empty elib_queue.o
0x08003e7c 0x08003e7c 0x00000030 Code RO 417 i.elib_queue_pop elib_queue.o
0x08003eac 0x08003eac 0x00000042 Code RO 418 i.elib_queue_pull elib_queue.o
0x08003eee 0x08003eee 0x00000056 Code RO 419 i.elib_queue_pull_pop elib_queue.o
0x08003f44 0x08003f44 0x00000040 Code RO 420 i.elib_queue_push elib_queue.o
0x08003f84 0x08003f84 0x00000002 Code RO 653 i.fkey_null_func shell.o
0x08003f86 0x08003f86 0x00000002 PAD
0x08003f88 0x08003f88 0x00000044 Code RO 610 i.fputc elab_log.o
0x08003fcc 0x08003fcc 0x00000024 Code RO 274 i.led_init led.o
0x08003ff0 0x08003ff0 0x00000040 Code RO 275 i.led_poll led.o
0x08004030 0x08004030 0x0000000e Code RO 1 i.main main.o
0x0800403e 0x0800403e 0x00000002 Code RO 481 i.module_null_init elab_export.o
0x08004040 0x08004040 0x00000028 Code RO 654 i.shellAdd shell.o
0x08004068 0x08004068 0x0000000e Code RO 655 i.shellBackspace shell.o
0x08004076 0x08004076 0x00000002 PAD
0x08004078 0x08004078 0x00000044 Code RO 656 i.shellCheckPassword shell.o
0x080040bc 0x080040bc 0x0000003e Code RO 657 i.shellCheckPermission shell.o
0x080040fa 0x080040fa 0x00000002 PAD
0x080040fc 0x080040fc 0x0000001c Code RO 658 i.shellClear shell.o
0x08004118 0x08004118 0x00000028 Code RO 659 i.shellClearCommandLine shell.o
0x08004140 0x08004140 0x00000014 Code RO 660 i.shellCmds shell.o
0x08004154 0x08004154 0x00000010 Code RO 661 i.shellDelete shell.o
0x08004164 0x08004164 0x000000de Code RO 662 i.shellDeleteByte shell.o
0x08004242 0x08004242 0x00000002 PAD
0x08004244 0x08004244 0x00000028 Code RO 663 i.shellDeleteCommandLine shell.o
0x0800426c 0x0800426c 0x00000010 Code RO 664 i.shellDown shell.o
0x0800427c 0x0800427c 0x00000014 Code RO 666 i.shellEnter shell.o
0x08004290 0x08004290 0x0000007c Code RO 667 i.shellExec shell.o
0x0800430c 0x0800430c 0x0000005a Code RO 1048 i.shellExtNumType shell_ext.o
0x08004366 0x08004366 0x00000046 Code RO 1049 i.shellExtParseChar shell_ext.o
0x080043ac 0x080043ac 0x000000e6 Code RO 1050 i.shellExtParseNumber shell_ext.o
0x08004492 0x08004492 0x0000005c Code RO 1051 i.shellExtParsePara shell_ext.o
0x080044ee 0x080044ee 0x0000004a Code RO 1052 i.shellExtParseString shell_ext.o
0x08004538 0x08004538 0x00000026 Code RO 1053 i.shellExtParseVar shell_ext.o
0x0800455e 0x0800455e 0x000000ce Code RO 1054 i.shellExtRun shell_ext.o
0x0800462c 0x0800462c 0x00000036 Code RO 1055 i.shellExtToNum shell_ext.o
0x08004662 0x08004662 0x00000030 Code RO 668 i.shellGetCommandDesc shell.o
0x08004692 0x08004692 0x00000002 PAD
0x08004694 0x08004694 0x00000050 Code RO 669 i.shellGetCommandName shell.o
0x080046e4 0x080046e4 0x00000034 Code RO 670 i.shellGetCurrent shell.o
0x08004718 0x08004718 0x00000056 Code RO 671 i.shellGetVarValue shell.o
0x0800476e 0x0800476e 0x00000002 PAD
0x08004770 0x08004770 0x00000100 Code RO 672 i.shellHandler shell.o
0x08004870 0x08004870 0x0000002e Code RO 673 i.shellHelp shell.o
0x0800489e 0x0800489e 0x000000c0 Code RO 674 i.shellHistory shell.o
0x0800495e 0x0800495e 0x00000080 Code RO 675 i.shellHistoryAdd shell.o
0x080049de 0x080049de 0x00000002 PAD
0x080049e0 0x080049e0 0x000000a8 Code RO 676 i.shellInit shell.o
0x08004a88 0x08004a88 0x000000e0 Code RO 677 i.shellInsertByte shell.o
0x08004b68 0x08004b68 0x00000014 Code RO 678 i.shellKeys shell.o
0x08004b7c 0x08004b7c 0x0000001a Code RO 679 i.shellLeft shell.o
0x08004b96 0x08004b96 0x0000000c Code RO 680 i.shellListAll shell.o
0x08004ba2 0x08004ba2 0x00000002 PAD
0x08004ba4 0x08004ba4 0x0000004c Code RO 681 i.shellListCommand shell.o
0x08004bf0 0x08004bf0 0x000000f8 Code RO 682 i.shellListItem shell.o
0x08004ce8 0x08004ce8 0x0000005c Code RO 683 i.shellListKey shell.o
0x08004d44 0x08004d44 0x0000005c Code RO 684 i.shellListUser shell.o
0x08004da0 0x08004da0 0x0000005c Code RO 685 i.shellListVar shell.o
0x08004dfc 0x08004dfc 0x0000001c Code RO 686 i.shellNormalInput shell.o
0x08004e18 0x08004e18 0x00000096 Code RO 687 i.shellParserParam shell.o
0x08004eae 0x08004eae 0x00000068 Code RO 689 i.shellRemoveParamQuotes shell.o
0x08004f16 0x08004f16 0x0000001e Code RO 690 i.shellRight shell.o
0x08004f34 0x08004f34 0x000000b4 Code RO 692 i.shellRunCommand shell.o
0x08004fe8 0x08004fe8 0x00000082 Code RO 693 i.shellSeekCommand shell.o
0x0800506a 0x0800506a 0x00000002 PAD
0x0800506c 0x0800506c 0x00000068 Code RO 694 i.shellSetUser shell.o
0x080050d4 0x080050d4 0x0000006c Code RO 695 i.shellSetVar shell.o
0x08005140 0x08005140 0x00000098 Code RO 696 i.shellSetVarValue shell.o
0x080051d8 0x080051d8 0x000000c0 Code RO 697 i.shellShowVar shell.o
0x08005298 0x08005298 0x0000002e Code RO 698 i.shellStringCompare shell.o
0x080052c6 0x080052c6 0x00000018 Code RO 699 i.shellStringCopy shell.o
0x080052de 0x080052de 0x00000002 PAD
0x080052e0 0x080052e0 0x00000124 Code RO 700 i.shellTab shell.o
0x08005404 0x08005404 0x0000005a Code RO 702 i.shellToDec shell.o
0x0800545e 0x0800545e 0x00000002 PAD
0x08005460 0x08005460 0x00000024 Code RO 703 i.shellToHex shell.o
0x08005484 0x08005484 0x0000000e Code RO 704 i.shellUp shell.o
0x08005492 0x08005492 0x00000014 Code RO 705 i.shellUsers shell.o
0x080054a6 0x080054a6 0x00000014 Code RO 706 i.shellVars shell.o
0x080054ba 0x080054ba 0x0000000e Code RO 707 i.shellWriteByte shell.o
0x080054c8 0x080054c8 0x0000005c Code RO 708 i.shellWriteCommandDesc shell.o
0x08005524 0x08005524 0x00000068 Code RO 709 i.shellWriteCommandHelp shell.o
0x0800558c 0x0800558c 0x00000070 Code RO 711 i.shellWritePrompt shell.o
0x080055fc 0x080055fc 0x00000070 Code RO 712 i.shellWriteReturnValue shell.o
0x0800566c 0x0800566c 0x00000022 Code RO 713 i.shellWriteString shell.o
0x0800568e 0x0800568e 0x00000002 PAD
0x08005690 0x08005690 0x0000002c Code RO 240 i.shell_poll shell_export.o
0x080056bc 0x080056bc 0x00000034 Code RO 241 i.shell_uart_init shell_export.o
0x080056f0 0x080056f0 0x00000058 Code RO 1098 i.test_func_led test_led.o
0x08005748 0x08005748 0x000000eb Data RO 715 .constdata shell.o
0x08005833 0x08005833 0x00000025 Data RO 1099 .constdata test_led.o
0x08005858 0x08005858 0x00000068 Data RO 1162 .constdata system_stm32g0xx.o
0x080058c0 0x080058c0 0x00000020 Data RO 2006 .constdata stm32g0xx_hal_uart.o
0x080058e0 0x080058e0 0x0000004c Data RO 44 .conststring eio_pin.o
0x0800592c 0x0800592c 0x0000000b Data RO 482 .conststring elab_export.o
0x08005937 0x08005937 0x00000001 PAD
0x08005938 0x08005938 0x000001d8 Data RO 716 .conststring shell.o
0x08005b10 0x08005b10 0x00000015 Data RO 243 .conststrlit shell_export.o
0x08005b25 0x08005b25 0x00000003 PAD
0x08005b28 0x08005b28 0x00000011 Data RO 278 .conststrlit led.o
0x08005b39 0x08005b39 0x00000003 PAD
0x08005b3c 0x08005b3c 0x00000019 Data RO 483 .conststrlit elab_export.o
0x08005b55 0x08005b55 0x00000003 PAD
0x08005b58 0x08005b58 0x00000020 Data RO 3363 Region$$Table anon$$obj.o
0x08005b78 0x08005b78 0x0000001c Data RO 245 elab_export shell_export.o
0x08005b94 0x08005b94 0x0000001c Data RO 280 elab_export led.o
0x08005bb0 0x08005bb0 0x0000001c Data RO 485 elab_export elab_export.o
0x08005bcc 0x08005bcc 0x0000001c Data RO 246 expoll shell_export.o
0x08005be8 0x08005be8 0x0000001c Data RO 281 expoll led.o
0x08005c04 0x08005c04 0x0000001c Data RO 486 expoll elab_export.o
0x08005c20 0x08005c20 0x000004c0 Data RO 718 shellCommand shell.o
0x080060e0 0x080060e0 0x00000040 Data RO 1100 shellCommand test_led.o
Flash又可以细分为文本段、只读数据段、数据复制段。
其中文本段包含代码和代码中的常量部分。
只读数据区通常存放程序中以const关键字修饰的数据。
数据复制段存放的则是程序中初始化不为0的全局变量的数据，在每次单片机复位后要对这些变量重新赋值。
可以看到被调用的HAL库的函数、应用程序自定义的函数都被放在了FLASH中，编译器会自动给他们分配不同的section。
用户也可以使用__attribute__((section(x)))来自定义section。
以letter shell中的代码为例：
#ifndef SHELL_SECTION
#if defined(__CC_ARM) || defined(__CLANG_ARM)
#define SHELL_SECTION(x) __attribute__((section(x)))
#elif defined (__IAR_SYSTEMS_ICC__)
#define SHELL_SECTION(x) @ x
#elif defined(__GNUC__)
#define SHELL_SECTION(x) __attribute__((section(x)))
#else
#define SHELL_SECTION(x)
#endif
#endif
#define SHELL_EXPORT_CMD(_attr, _name, _func, _desc) \
const char shellCmd##_name[] = #_name; \
const char shellDesc##_name[] = #_desc; \
SHELL_USED const ShellCommand \
shellCommand##_name SHELL_SECTION("shellCommand") = \
{ \
.magic_head = SHELL_MAGIC_NUM, \
.magic_tail = SHELL_MAGIC_NUM, \
.attr.value = _attr, \
.data.cmd.name = shellCmd##_name, \
.data.cmd.function = (int (*)())_func, \
.data.cmd.desc = shellDesc##_name \
}
使用SHELL_EXPORT_CMD定义的某个命令的数据结构会存放在名为shellCommand的section中。
由于数据结构前声明为const，所以最终会存放在Flash中。
如果前面没有被声明为const，则对应的数据结构会被存放在RAM中。
RAM布局
image-20240118111439157.png
data段：存放初始化非0的全局变量
bss段：存放未初始化或初始化为0的全局变量
Heap（堆）段：由程序员通过malloc/free申请和释放
Stack（栈）段：存放局部变量和函数的入口地址
Execution Region RW_IRAM1 (Exec base: 0x20000000, Load base: 0x08006140, Size: 0x00000a88, Max: 0x00009000, ABSOLUTE)
Exec Addr Load Addr Size Type Attr Idx E Section Name Object
0x20000000 0x08006140 0x00000014 Data RW 45 .data eio_pin.o
0x20000014 0x08006154 0x00000004 Data RW 244 .data shell_export.o
0x20000018 0x08006158 0x00000008 Data RW 279 .data led.o
0x20000020 0x08006160 0x00000004 Data RW 330 .data elab_time.o
0x20000024 0x08006164 0x00000001 Data RW 359 .data elab_uart_debug.o
0x20000025 0x08006165 0x00000003 PAD
0x20000028 0x08006168 0x00000019 Data RW 484 .data elab_export.o
0x20000041 0x08006181 0x00000002 Data RW 614 .data elab_log.o
0x20000043 0x08006183 0x00000001 PAD
0x20000044 0x08006184 0x00000060 Data RW 717 .data shell.o
0x200000a4 0x080061e4 0x00000004 Data RW 1164 .data system_stm32g0xx.o
0x200000a8 0x080061e8 0x00000009 Data RW 1230 .data stm32g0xx_hal.o
0x200000b1 0x080061f1 0x00000003 PAD
0x200000b4 0x080061f4 0x00000004 Data RW 3330 .data mc_p.l(stdout.o)
0x200000b8 0x080061f8 0x0000001c Data RW 245 elab_export shell_export.o
0x200000d4 0x08006214 0x0000001c Data RW 280 elab_export led.o
0x200000f0 0x08006230 0x0000001c Data RW 485 elab_export elab_export.o
0x2000010c - 0x00000274 Zero RW 242 .bss shell_export.o
0x20000380 - 0x0000000c Zero RW 276 .bss led.o
0x2000038c - 0x000001b8 Zero RW 357 .bss elab_uart_debug.o
0x20000544 - 0x00000120 Zero RW 611 .bss elab_log.o
0x20000664 - 0x0000001d Zero RW 714 .bss shell.o
0x20000681 0x0800624c 0x00000007 PAD
0x20000688 - 0x00000400 Zero RW 1192 STACK startup_stm32g070xx.o
