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Hi, i want to build a kind of soundbox-toy. It has grown so i need a few more extra bytes of RAM memory. Unfortunately the printed circuit board is ready. So i can not add some external memory.
It is allowed to modify the startup.s file? Reducing stack to get a little more memory?
How to test out the limits? Can i do this at all? I'am worried a little, all this stuff in the startup file looks very complicated to me. Afraid of doing the wrong things!
I'am using a ADuC7026 it has only 8 kByte of RAM memory. Here's my startup.s file
/***********************************************************************/ Mode_USR EQU 0x10 Mode_FIQ EQU 0x11 Mode_IRQ EQU 0x12 Mode_SVC EQU 0x13 Mode_ABT EQU 0x17 Mode_UND EQU 0x1B Mode_SYS EQU 0x1F I_Bit EQU 0x80 /* when I bit is set, IRQ is disabled */ F_Bit EQU 0x40 /* when F bit is set, FIQ is disabled */ UND_Stack_Size EQU 0x00000004 SVC_Stack_Size EQU 0x00000004 ABT_Stack_Size EQU 0x00000004 FIQ_Stack_Size EQU 0x00000004 IRQ_Stack_Size EQU 0x00000080 USR_Stack_Size EQU 0x00000400 AREA STACK, DATA, READWRITE, ALIGN=2 DS (USR_Stack_Size+3)&~3 ; Stack for User/System Mode DS (SVC_Stack_Size+3)&~3 ; Stack for Supervisor Mode DS (IRQ_Stack_Size+3)&~3 ; Stack for Interrupt Mode DS (FIQ_Stack_Size+3)&~3 ; Stack for Fast Interrupt Mode DS (ABT_Stack_Size+3)&~3 ; Stack for Abort Mode DS (UND_Stack_Size+3)&~3 ; Stack for Undefined Mode Top_Stack: // MMR definitions MMR_BASE EQU 0xFFFF0000 ; MMR Base Address REMAP_OFFSET EQU 0x0220 PREMAP_OFFSET EQU 0x0224 POWKEY1_OFFSET EQU 0x0404 POWCON_OFFSET EQU 0x0408 POWKEY2_OFFSET EQU 0x040C PLL_SETUP EQU 1 PLLCFG_Val EQU 0x00000000 // alter Wert war 0x00000001 GPIO_SETUP EQU 1 GPIOBASE EQU 0xFFFFF400 GP0CON_Val EQU 0x00000000 GP1CON_Val EQU 0x00000000 GP2CON_Val EQU 0x00000000 GP3CON_Val EQU 0x00000000 GP4CON_Val EQU 0x00000000 $IF (RAM_INTVEC) // Exception Vector Area in RAM AREA VECTORS, DATA, AT 0x00010000 DS 64 $ENDIF // Startup Code must be linked at address which it expects to run. AREA STARTUPCODE, CODE, AT 0x00080000 PUBLIC __startup EXTERN CODE32 (?C?INIT) __startup PROC CODE32 // Pre-defined interrupt handlers that may be directly // overwritten by C interrupt functions EXTERN CODE32 (Undef_Handler?A) EXTERN CODE32 (SWI_Handler?A) EXTERN CODE32 (PAbt_Handler?A) EXTERN CODE32 (DAbt_Handler?A) EXTERN CODE32 (IRQ_Handler?A) EXTERN CODE32 (FIQ_Handler?A) // Exception Vectors // Mapped to Address 0. // Absolute addressing mode must be used. Vectors: LDR PC,Reset_Addr LDR PC,Undef_Addr LDR PC,SWI_Addr LDR PC,PAbt_Addr LDR PC,DAbt_Addr NOP /* Reserved Vector */ LDR PC,IRQ_Addr LDR PC,FIQ_Addr Reset_Addr: DD Reset_Handler Undef_Addr: DD Undef_Handler?A SWI_Addr: DD SWI_Handler?A PAbt_Addr: DD PAbt_Handler?A DAbt_Addr: DD DAbt_Handler?A DD 0 /* Reserved Address */ IRQ_Addr: DD IRQ_Handler?A FIQ_Addr: DD FIQ_Handler?A // Reset Handler Reset_Handler: // Setup PLL IF (PLL_SETUP != 0) LDR R0, =MMR_BASE MOV R1, #0x01 STR R1, [R0,#POWKEY1_OFFSET] MOV R1, #PLLCFG_Val STR R1, [R0,#POWCON_OFFSET] MOV R1, #0xF4 STR R1, [R0,#POWKEY2_OFFSET] ENDIF ; PLL_SETUP // Setup Pins IF (GPIO_SETUP != 0) ADR R10, GPIO_CFG /* Pointer to GPIO CFG */ LDMIA R10, {R0-R5} /* Load GPIO Configuration */ STMIA R0, {R1-R5} /* Store GPxCON */ B GPIO_END GPIO_CFG: DD GPIOBASE DD GP0CON_Val DD GP1CON_Val DD GP2CON_Val DD GP3CON_Val DD GP4CON_Val GPIO_END: ENDIF ; GPIO_SETUP // Setup Stack for each mode LDR R0, =Top_Stack // Enter Undefined Instruction Mode and set its Stack Pointer MSR CPSR_c, #Mode_UND|I_Bit|F_Bit MOV SP, R0 SUB R0, R0, #UND_Stack_Size // Enter Abort Mode and set its Stack Pointer MSR CPSR_c, #Mode_ABT|I_Bit|F_Bit MOV SP, R0 SUB R0, R0, #ABT_Stack_Size // Enter FIQ Mode and set its Stack Pointer MSR CPSR_c, #Mode_FIQ|I_Bit|F_Bit MOV SP, R0 SUB R0, R0, #FIQ_Stack_Size // Enter IRQ Mode and set its Stack Pointer MSR CPSR_c, #Mode_IRQ|I_Bit|F_Bit MOV SP, R0 SUB R0, R0, #IRQ_Stack_Size // Enter Supervisor Mode and set its Stack Pointer MSR CPSR_c, #Mode_SVC|I_Bit|F_Bit MOV SP, R0 SUB R0, R0, #SVC_Stack_Size // Enter User Mode and set its Stack Pointer MSR CPSR_c, #Mode_USR MOV SP, R0 // Enter the C code LDR R0,=?C?INIT TST R0,#1 ; Bit-0 set: main is Thumb LDREQ LR,=exit?A ; ARM Mode LDRNE LR,=exit?T ; Thumb Mode BX R0 ENDP PUBLIC exit?A exit?A PROC CODE32 B exit?A ENDP PUBLIC exit?T exit?T PROC CODE16 B exit?T ENDP END
@ Andy Neil Is this the same question: http://www.keil.com/forum/docs/thread11749.asp
No, same projekt, but different question.
The topic of this thread is: How to modify startup.s to get a little more memory for variables.
Why did you post a full startup.s file?
Is it a modified file, or the original file you got with your installation?
Yes, you can modify the parameters for size of interrupt stack and main stack. The problem is that you must try out every possible branch combination to make sure that you find out which one is deepest.
The good thing is that as long as your program isn't recursive, the compiler will help you. You can have it generate a HTML page (named <project_name>.htm in your output directory) with a stack analysis. The HTML page will display an analysis of possible call tree chains, max stack needed and how much stack is consumed for each individual function call.
@ Per Westermark
Thanks for your patience with my ignorance.
Unfortunately i can not find this stack analysis HTML file. Would be happy to receive more hints :-)
Best regards
Open your project options.
Select page 'Listing'
Turn on 'Linker Listing'
Make sure that you have 'Callgraph' checked.
Build project and look in your output directory for a file named '<project>.htm'.
However, as mentioned before, it is only a static call graph. It will not help you if you make use of recursive functions.