2009-03-24 11:24:59     bf537 how to jump ram from flash

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2009-03-24 11:24:59     bf537 how to jump ram from flash

feng li (CHINA)

Message: 71454   

 

recently i looked the statrt.S of uboot code of bf537,when init_sdram is executed,"call get_pc",then i  found anothe "get_pc" at last of the start code.i do not know where is "get_pc",and how to jump to ram.who can giev me  a help or exlaination!!

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2009-03-24 15:10:36     Re: bf537 how to jump ram from flash

Mike Frysinger (UNITED STATES)

Message: 71461   

 

sorry, i really dont understand what you're asking.  try reading the documentation:

http://docs.blackfin.uclinux.org/doku.php?id=bootloaders:u-boot:debugging

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2009-03-26 11:45:08     Re: bf537 how to jump ram from flash

feng li (CHINA)

Message: 71610   

 

sorry ,i am not good at english.my custom board already worked,cpu is bf537,but i am not well-known about the process of start.S.after init-sdram,relocate into to RAM,here i met a question.as following "????"

 

/* relocate into to RAM */

call get_pc;                 /* ro = rets  ,ro get the address of  token of  "offset"*/

offset:

r2.l = offset;

r2.h = offset;

r3.l = start;

r3.h = start;

r1 = r2 - r3;                       /* the length of start to offset */

 

r0 = r0 - r1;                      /*??????what meaning?????,r0 = ????*/

p1 = r0;

 

p2.l = (CFG_MONITOR_BASE & 0xffff);

p2.h = (CFG_MONITOR_BASE >> 16);

 

p3 = 0x04;

p4.l = ((CFG_MONITOR_BASE + CFG_MONITOR_LEN) & 0xffff);

p4.h = ((CFG_MONITOR_BASE + CFG_MONITOR_LEN) >> 16);

loop1:

r1 = [p1 ++ p3];

[p2 ++ p3] = r1;

cc=p2==p4;

if !cc jump loop1;

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2009-03-26 11:52:46     Re: bf537 how to jump ram from flash

feng li (CHINA)

Message: 71612   

 

i think maybe i made a mistake somewhere, could you tell me what documents should i take a look?

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2009-03-26 12:29:14     Re: bf537 how to jump ram from flash

Mike Frysinger (UNITED STATES)

Message: 71613   

 

you're apparently looking at old code.  the latest stuff has comments you can read.

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