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MPC5746C Boot Assist Flash (BAF)

Question asked by Christopher Holland on Jul 10, 2018
Latest reply on Jul 11, 2018 by Christopher Holland

So, I am starting my foray into figuring out how to get the Boot Assist Flash to work.

Well, from what I understand, if the Boot Header is not found, the BAF will perform a Serial boot.

The Serial boot requires a BAF formatted file.

 

I figured out how to get the flash driver to work, which allowed me to erase the Boot header.

So, hopefully I am now in Serial boot mode. (Maybe S32 has some way to just erase the flash w/o programming?)

 

I figured out how to get an srec formatted file out of S32 Design Studio.

I noticed that addresses were not contiguous, so I checked a couple of ticks in S32 Design studio

 

That seemed to make the addresses contiguous.

Next, I chopped it up the .SREC file to leave just the code bytes.

I then added the Password, Load address, VLE bit and program byte length 

as shown below.

 

/////////  Original SREC Formatted File /////////////

S014000050524A5F4D504335373436422E73726563CD
S31501002C007068E00070E8E0001C6302841CE702843F

....

S70501000000F9

 

///////// BAF Formatted File /////////////

FEEDFACECAFEBEEF
01000000
8001D3D5
7068E00070E8E0001C6302841CE70284

....

0102431C01

 

I am using the EVB board, so the external xtal is 80 Mhz, which means I would need 96,000 baud.

I was able to just type in the baud rate on Tera Term VT so hopefully that works.

 

I tried sending a file or just sending the password and hope for some echo, but I don't see anything and I am wondering what, if anything, I am doing wrong.

I don't know if anybody else has tried this? I don't see any examples. 

There's not too much discussion of BAF.

Hopefully I am headed in the right direction.

 

Thanks for your help.

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