[SOLVED] in keil whats the using startup file for any micro?

when we create a project in keil,we have a file startup,my question is whats application of this files?

thanks for reply

I believe looking at the code will almost answer the question. It's performing basic processor register as well as compiler run time environment initializations, e.g. of the stack pointer.

so it is should be assembly language....

thanks for reply.now the this files for stm micro published with keil or stm coporation,i have doubt ,it is mentioned created with stm,

;******************** (C) COPYRIGHT 2011 STMicroelectronics ********************
;* File Name : startup_stm32f10x_cl.s
;* Author : MCD Application Team
;* Version : V3.5.0
;* Date : 11-March-2011
;* Description : STM32F10x Connectivity line devices vector table for MDK-ARM
;* toolchain.

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my question is in iar or gnu arm compiler a startup file is exactly same keil?thanks for reply.

Not mandatory to use assembly language. I have seen start up files on C. The main purpose is to define vectors for interrupts.

thanks but for this special case stm keil is assembly.:
this is part of source

__user_initial_stackheap

LDR R0, = Heap_Mem
LDR R1, =(Stack_Mem + Stack_Size)
LDR R2, = (Heap_Mem + Heap_Size)
LDR R3, = Stack_Mem
BX LR

ALIGN

ENDIF

END

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my question is in iar or gnu arm compiler a startup file is exactly same keil?

Click to expand...

Unlikely the same, but providing similar functionality. Your latest example is e.g. assigning memory space for a heap which might be not used by a specific compiler.

I believe that your original question has been answered, also you usually don't have to care for startup files in a standard application because it works well with the predefined startup. In case you want to achieve something special, it's assumed that you have sufficient knowledge of processor register model (and possibly assembly language) to modify the existing startup files or write your own.