Keil Firmware size

romlen needs to be the first word on the line, hard to the left margin.

In startup.s is a good place

...
; Reset handler routine
Reset_Handler   PROC
                EXPORT  Reset_Handler                 [WEAK]
                IMPORT  __main
                IMPORT  SystemInit

                LDR     R0, =SystemInit
                BLX     R0
                LDR     R0, =__main
                BX      R0

                ENDP ; sourcer32@gmail.com

        IMPORT  ||Load$$LR$$LR_IROM1$$Length||
        EXPORT  romlen
romlen  DCD     ||Load$$LR$$LR_IROM1$$Length||

...

Access from C via

extern uint32_t romlen;
...
printf("%08X\n", romlen);

romlen needs to be the first word on the line, hard to the left margin.

In startup.s is a good place

...
; Reset handler routine
Reset_Handler   PROC
                EXPORT  Reset_Handler                 [WEAK]
                IMPORT  __main
                IMPORT  SystemInit

                LDR     R0, =SystemInit
                BLX     R0
                LDR     R0, =__main
                BX      R0

                ENDP ; sourcer32@gmail.com

        IMPORT  ||Load$$LR$$LR_IROM1$$Length||
        EXPORT  romlen
romlen  DCD     ||Load$$LR$$LR_IROM1$$Length||

...

Access from C via

extern uint32_t romlen;
...
printf("%08X\n", romlen);

Hi Clive,

after placing the LR stuff into the startup.s file I am getting a linker error

.\Objects\bootloader_adv.axf: Error: L6218E: Undefined symbol Load$$LR$$LR_IROM1$$Length (referred from arm_startup_nrf52.o).

I have been looking around on the web and stumbled across some sites like this one

infocenter.arm.com/.../index.jsp

I tried adding in the R0, RW, and ZI regions but still no luck. here is what mine looks like in

; Reset Handler

Reset_Handler PROC EXPORT Reset_Handler [WEAK] IMPORT SystemInit IMPORT __main

LDR R0, =SystemInit BLX R0 LDR R0, =__main BX R0 ENDP

IMPORT ||Load$$LR$$LR_IROM1$$R0$$Length|| EXPORT romlen
romlen DCD ||Load$$LR$$LR_IROM1$$R0$$Length||

; Dummy Exception Handlers (infinite loops which can be modified)

NMI_Handler PROC

Do I have to add anything to the linker options in the flash configuration settings?

If you have a scatter file check what the name of the load region is, I used the generic one Keil uses for IROM1 in the auto generated files. I'm just cutting and pasting into an STM32 project building in uV 5.22, no magic involved.

Auto generated .SCT file, note "LR_IROM1", the final size of the output being computed

; *************************************************************
; *** Scatter-Loading Description File generated by uVision ***
; *************************************************************

LR_IROM1 0x08000000 0x00030000  {    ; load region size_region
  ER_IROM1 0x08000000 0x00030000  {  ; load address = execution address
   *.o (RESET, +First)
   *(InRoot$$Sections)
   .ANY (+RO)
  }
  RW_IRAM1 0x20000000 0x00005000  {  ; RW data
   .ANY (+RW +ZI)
  }
}

Ah, I was not using a scatter file. Can you explain what a scatter file does for me? All this reading from keils forum it looks like all a scatter file does is breakdown the regions of where data is being dumped?

You shouldn't need one, look for a project.sct type file in the output directory where it puts the .AXF, .HEX and .MAP files.

The region naming is important for the symbol to work