我是一个初学者，有没有人知道，怎样用用ADS汇编怎样实现打开一个文本的编程阿，有高手吗？用到SWI
下面是问题：
Refer to the ARM System Calls document and read about the following system calls:ffice ffice" />
SWI_Open, SWI_Flen, SWI_Read, SWI_Write. An example is given to show how you can write a short file on disk. Write a program to open the file turing.txt, and print its content on the screen. (More system calls information on http://www.arm.com, look for ADS 1.2 Debugger Target Guide) Two examples of system calls are attached at the end of this assignment specification. (One is outputting string to the debugger console, one is writing string to a file on the host debugger (PC).
例如：
AREA Hello_Word, CODE, READONLY ; name this block of code
; function ID codes to be put into r0
SWI_WriteC EQU 0x03 ;output character address in r1
SWI_Exit EQU 0x18 ;finish program
SWI_FUN EQU 0x123456
ENTRY ;code entry point
START LDR r1,=TEXT
SUB r1,r1,#1
LDR r0, = SWI_WriteC
ffice:smarttags" />LOOP ADD r1,r1,#1
LDRB r2, [r1]
CMP r2, #0
SWINE SWI_FUN
BNE LOOP
LDR r0, = SWI_Exit
SWI SWI_FUN
TEXT DCB "Hello World!", &0a, &0d, 0 ; string + CR + LF + null
END | 
