MTK bootup流程

wangsamuel

请高手详解.
thanks

yangyang7432

<P>不知, 帮顶, 等高手出现吧:)</P>

wangsamuel

<P>remapping机制, 谁了解</P>

wangsamuel

<P>o地址是</P><P>sram?  ext flash  or bootrom</P><P>如何如何请高手指点一二</P>

duzhengjun_3

<P>我这里有 需要的请联系我andysz19810225@hotmail.com</P>

richardlin

发到网上来啊！

chengmj

5楼的兄弟不会要卖RMB吧!上传到52RD吧!

yc0188

先从ROM开始启动的

buiker

<P>1.如果是download代码，则是从rom中启动，这点在cpu的datasheet中有图。</P><P>2。如果是开机。则代码是从flash中开始运行。请参考bootarm.s(project 中有)</P><P>起始的flash不一定为0。这里假设为0 </P><P>代码的起始是安装中断向量, cpu的所有中断都要经过这里。其实就是 </P><P>B int1</P><P>B int2 这样简单的几个语句啦</P><P>关中断，配置pll。如果大伙想自己调试，可以设置io口，作为</P><P>indication啦。</P><P>配置时序（最主要的flash的，ram的时序）</P><P>将必要的代码（资源就不要</P><P>搬运了）从flash中搬运到内存中，当然是loop来做啦。</P><P>重新加载pc（r15 ）指针，跳转到指定位置执行代码（此时代码在ram中）</P><P>如果有remapping，则跳转的方式，不仅是简单地设置pc指针，还有remap寄存器</P><P>以上的代码必须是汇编，此后的代码可以是c语言的了</P><P>代码开始设置系统内存，保留堆栈内存。即为操作系统保留资源。</P><P>这里主要是necleus。分为2部分</P><P>低级的，Init_initialise</P><P>高级的Inc_Initialize()</P><P>applicaition_initialization（）</P><P>kkai</P><P>tovootdai</P><P>aod</P>

songang01

<P>Boot Sequence
Since the ARM7EJ-S core always starts to fetch instructions from the lowest memory address at 00000000h (MB0) after
system being reset. It is designed to have a dynamic mapping architecture capable of associating Boot Code, external Flash
or external SRAM with memory block MB0.
By default, the Boot Code is mapped onto MB0 while the state of IBOOT is “0”. But, this configuration can be changed by
altering the state of IBOOT before system reset or programming bit value of RM1 in register EMI_REMAP directly.
MT6217 system provides two kinds of boot up scheme:
&#1048698; Start up system of running codes from Boot Code for factory programming
&#1048698; Start up system of running codes from external FLASH or ROM device for normal operation</P><P>Boot Code
The Boot Code is placed together with Memory Re-Mapping Mechanism in External Memory Controller and comprises
just two words of instructions as shown below. It is quite obvious that there is a jump instruction that leads the processor to
run the code started at address of 48000000h where the System ROM is placed.
ADDRESS BINARY CODE ASSEMBLY
00000000h E51FF004h LDR PC, 0x4
00000004h 48000000h (DATA)</P>

找到自我

boot sequece可以在MTK baseband training presentation中找到，这部分说得很详细的哦，想了解的话可以发站内消息给我就好，[em01]

Water_Lee

<P>只能意会一点，看了Linux的启动的代码</P>