?? 嵌入式---程序示例3.htm
字號:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- saved from url=(0043)http://drew.nease.net/mypage/sourcecode.htm -->
<HTML><HEAD><TITLE>嵌入式---程序示例</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<META content="MSHTML 6.00.2800.1106" name=GENERATOR></HEAD>
<BODY background=嵌入式---程序示例3.files/background.gif>
<P>>><BIG><BIG><A name=returntop></A></BIG><A
href="http://drew.nease.net/">Drew的主頁</A></BIG>---->程序示例</P>
<DIV align=center>
<CENTER>
<TABLE borderColor=#88deea height=23 cellSpacing=1 borderColorDark=#88deea
width=754 bgColor=#ffffff borderColorLight=#88deea
background=嵌入式---程序示例3.files/404.htm border=1>
<TBODY>
<TR>
<TD align=middle width=83 height=1>
<P align=center><A href="http://drew.nease.net/"><BIG>主頁</BIG></A></P></TD>
<TD align=middle width=83 height=1>
<P align=center><A href="http://drew.nease.net/mypage/VxWorks.htm"><FONT
lang=ZH-CN face=System>VxWorks</FONT></A></P></TD>
<TD align=middle width=84 height=1>
<P align=center><A href="http://drew.nease.net/processor/arm.htm"><FONT
lang=ZH-CN face=System>ARM</FONT></A></P></TD>
<TD align=middle width=84 height=1>
<P align=center><A href="http://drew.nease.net/processor/mpc860.htm"><FONT
lang=ZH-CN face=System>PowerPC</FONT></A></P></TD>
<TD align=middle width=84 height=1>
<P align=center><A href="http://drew.nease.net/mypage/driver.htm"><FONT
lang=ZH-CN face=System>硬件驅動</FONT></A></P></TD>
<TD align=middle width=84 height=1>
<P align=center><A href="http://drew.nease.net/mypage/network.htm"><FONT
lang=ZH-CN face=System>網絡協議</FONT></A></P></TD>
<TD align=middle width=84 height=1>
<P align=center><FONT lang=ZH-CN face=System>程序示例</FONT></P></TD>
<TD align=middle width=84 height=1><A href="http://www.embhelp.com/bbs"
target=_blank><FONT face=System color=#8000ff>技術論壇</FONT></A></TD>
<TD align=middle width=84 height=1>
<P align=center><A href="http://www.embhelp.com/download"><FONT lang=ZH-CN
face=System>下載</FONT></A></P></TD></TR></TBODY></TABLE></CENTER></DIV>
<P align=center> </P>
<P align=center><FONT
color=#0000ff><BIG><BIG><BIG>程序示例</BIG></BIG></BIG></FONT></P>
<P align=center> </P>
<P><BIG><STRONG>
這里是一些程序示例和源碼解釋.一些相關程序代碼會陸續補上.相關問題可參見</STRONG></BIG><A
href="http://drew.nease.net/mypage/driver.htm" target=_blank><FONT lang=ZH-CN
face=System>硬件驅動</FONT></A></P>
<BLOCKQUOTE>
<DIV align=left>
<TABLE height=269 width=529 border=0>
<TBODY>
<TR>
<TD width=254 height=33><B><A
href="http://drew.nease.net/mypage/sourcecode.htm#INIT">系統初始化(PowerPC匯編)</A>
</B></TD>
<TD width=263 height=33><A
href="http://drew.nease.net/mypage/example/config.htm"><B>VxWorks
BSP文件配置及生成下載</B></A><B> </B></TD></TR>
<TR>
<TD width=254 height=33><A
href="http://drew.nease.net/mypage/sourcecode.htm#INT"><B>硬件中斷</B></A></TD>
<TD width=263 height=33><A
href="http://drew.nease.net/mypage/sourcecode.htm#NIC"><B>VxWorks網絡驅動</B></A></TD></TR>
<TR>
<TD width=254 height=33><A
href="http://drew.nease.net/mypage/example/flashrom.htm"><B>FlashROM驅動(ARM匯編)</B></A></TD>
<TD width=263 height=33><A
href="http://drew.nease.net/mypage/example/ARM_Boot.htm"><B>ARM Boot
Load程序(ARM匯編)</B></A></TD></TR>
<TR>
<TD width=254 height=34><A
href="http://drew.nease.net/mypage/example/UART.htm"><B>串口(UART)程序示例</B></A></TD>
<TD width=263 height=34><A
href="http://drew.nease.net/mypage/example/pci.htm"><U><B>PCI設備(網卡)初始化代碼分析</B></U></A></TD></TR>
<TR>
<TD width=254 height=34><U><B>文件系統</B></U></TD>
<TD width=263 height=34></TD></TR>
<TR>
<TD width=254 height=34><A
href="http://drew.nease.net/mypage/sourcecode.htm#LCD"><B>LCD和觸摸屏</B></A></TD>
<TD width=263 height=34></TD></TR>
<TR>
<TD width=254 height=34><A
href="http://drew.nease.net/mypage/sourcecode.htm#MODEM"><B>MODEM
撥號</B></A></TD>
<TD width=263 height=34></TD></TR>
<TR>
<TD width=254 height=34><B><A
href="http://drew.nease.net/mypage/sourcecode.htm#RTC">實時時鐘 RTC</A>
</B></TD>
<TD width=263 height=34></TD></TR></TBODY></TABLE></DIV></BLOCKQUOTE>
<BLOCKQUOTE>
<P> </P></BLOCKQUOTE>
<P><A name=INIT></A><BIG><BIG><STRONG>系統初始化</STRONG></BIG></BIG></P>
<BLOCKQUOTE>
<P><STRONG>系統初始化對不同的CPU,基本步驟是類似的.</STRONG></P>
<P><STRONG>系統初始化的主要步驟如下</STRONG></P>
<BLOCKQUOTE>
<UL>
<LI><STRONG>啟動</STRONG>
<LI><STRONG>關閉中斷</STRONG>
<LI><STRONG>放boot type到堆棧</STRONG>
<LI><STRONG>清空緩存</STRONG> </LI></UL></BLOCKQUOTE>
<P><STRONG>VxWorks 系統的 PowerPC BSP,系統開機后執行的第一個函數
romInit(),在ROM的起點,這里是使用的PowerPC匯編語言</STRONG></P>
<BLOCKQUOTE>
<P>/* 定義內部函數 internals */<BR>.globl romInit /* start of system code
*/<BR>.globl _romInit /* start of system code */<BR><BR>/* 定義外部函數 externals
*/<BR>.extern romStart /* system initialization routine
*/<BR><BR>.text<BR>.align
2<BR><BR>/*******************************************************************************<BR>*
<BR>* romInit ( int startType /@ only used by 2nd entry point @/
)<BR>*/<BR><BR>romInit:<BR>_romInit:<BR>bl cold /* 冷啟動
*/<BR>bl warm /* 熱啟動 */<BR><BR>cold:<BR>li p5,
BOOT_COLD<BR>bl start /* skip over next instruction */<BR><BR>warm:<BR>or
p5, p0, p0 /* startType to p5
*/<BR><BR>start: /*
<STRONG>此處是系統啟動開始</STRONG> */</P>
<P>/* <STRONG>屏蔽MSR中CE,EE位,關閉所有的外部中斷</STRONG><BR>/*<BR>* Disable external
interrupts <BR>*/<BR><BR>mfmsr p0 /* p0 = msr */<BR>INT_MASK (p0, p1) /*
mask EE and CE bit */<BR>ori p1,p1,_PPC_MSR_ME /* enable machine checks
*/<BR>mtmsr p1 /* msr = p1 */<BR>isync<BR><BR>/*
<STRONG>下面兩步是按照硬件定義初始化一些SPR,DCR寄存器,置0或置1</STRONG></P>
<P><STRONG>/*
SPR是特殊功能寄存器,DCR為設備控制寄存器,還有MSR機器狀態寄存器,這些是PowerPC內核中很重要的寄存器</STRONG></P>
<P>/* 初始化SPR,DCR寄存器置0<BR>* Initalize registers that need to be set to
zero.<BR>*/<BR><BR>addi r4,r0,0x0000<BR>mtspr SGR,r4 /* 解鎖所有存儲區域 SPR 中 SGR
位置0 */<BR>mtspr ESR, r4 /* SPR中的錯誤狀態位 ESR 清0 */<BR>mtspr TCR, r4 /* 關閉所有的
timers */<BR>mtspr PIT, r4 /* 清0 PIT timer */<BR>mtdcr UICER, r4 /*
關閉中斷控制器(UIC)中的所有中斷 */<BR>mtspr XER, r4 /* 清0 integer exception 寄存器
*/<BR><BR>/* 初始化另一些SPR,DCR寄存器置1<BR>* Initalize registers that need to be
cleared with 0xFFFFFFFF.<BR>*/<BR><BR>addis r4,r0,0xffff<BR>ori
r4,r4,0xffff<BR>mtspr TSR, r4 /* timer */<BR>mtspr DBSR, r4 /* 調試狀態位置1
*/<BR>mtdcr UICSR, r4 /* 清除中斷控制器(UIC)中的所有 pending 中斷 */<BR>mtdcr dmasr, r4
/* DMA狀態寄存器置1 */<BR><BR>/*
<STRONG>PowerPC405用兩個緩存,一個是16K指令緩存(ICU),一個是6K數據緩存(DCU),下面是清空著兩個緩存,并根據硬件設置緩存</STRONG>
*/</P>
<P>/* 清空指令緩存 */<BR>/*BESR type regs ZZZZZZZZZZZZ <BR>* Invalidate the entire
instruction cache. This can be done<BR>* with a single iccci instruction in
the processor core.<BR>*/<BR><BR>iccci r0, r0<BR><BR>/*清空數據緩存<BR>*
Invalidate the entire data cache.<BR>* The 405 processor core in the 405GP
has 128 congruence classes.<BR>* Each cache line in the 405 processor is 32
bytes.<BR>*/<BR><BR>/*<BR>* Turn the instruction cache on for faster
boot-up.<BR>* Also, the icache is needed to help initialize Bank 0<BR>* of
the EBC to speed up accesses to flash.<BR>* address space
0x00000000-0x07ffffff is cached<BR>* address space 0xf8000000-0xffffffff is
cached<BR>*/<BR><BR>lis p0, HIADJ(_PPC403_ICCR_DEFAULT_VAL)<BR>addi p0, p0,
LO(_PPC403_ICCR_DEFAULT_VAL)<BR>mtspr _PPC403_ICCR,
p0<BR>isync<BR><BR>/*<STRONG>
初始化外部總線控制器(EBC)</STRONG>,<STRONG>跳轉指令BL,執行extBusCntlrInit</STRONG><BR>*
/<BR><BR>bl extBusCntlrInit<BR><BR>/*<BR>* Now that the EBC Bank 0 has been
set up, turn the I-cache off if<BR>* i-cache was not specified in config.h.
It is also invalidated<BR>* again.<BR>*/<BR><BR>#ifndef
USER_I_CACHE_ENABLE<BR>li p0, 0 /* clear p0 */<BR>mtspr _PPC403_ICCR, p0 /*
turn off i-cache */<BR>isync<BR>iccci r0, r0 /* invalidate the I-cache again
*/<BR>#endif<BR><BR>/* 初始化和SDRAM相關的IIC(inter-integrated circut)寄存器IIC0,<BR>*
Initialize IIC0 for use in automatic SDRAM configuration<BR>*/<BR><BR>#ifdef
LOCAL_MEM_AUTOSIZE<BR>bl iic0Init<BR>#endif<BR><BR>/*
<STRONG>初始化SDRAM</STRONG>,<STRONG>BL跳轉執行sdramInit</STRONG><BR>* Configure
the SDRAM controller only if this is a cold boot.<BR>* If the SDRAM
controller is reinitialized on a warm boot, the<BR>* boot line will get
wiped out because of the ECC SDRAM memory<BR>*
initialization.<BR>*/<BR><BR>li p0, BOOT_COLD<BR>and. p0, p0, p5 /* p5 is
saved at the entry of romInit */<BR>beq skip<BR><BR>bl
sdramInit<BR><BR>skip:<BR><BR>/*<BR>* Clear the CPU reservation
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -