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Starting Bootloader from Application

 
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Alex20q90

Bascom Member



Joined: 24 Sep 2007
Posts: 89

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PostPosted: Sat Mar 10, 2018 12:02 pm    Post subject: Starting Bootloader from Application Reply with quote

Hello,

i have a new problem! I use a ATMega8u2 mit LUFA Bootloader. In Bascom i can flash my Application with Bascom over the "FLIP"-Programmer directly via USB. It works.
If i would flash again, i need to pull down the /RESET-Pin to low to start the Bootloader.

A Try to call the bootloader-Adress from my App wont work.

Sample code:

Code:
$regfile = "M8u2def.dat"
$crystal = 8000000

Switch Alias Pinc.2                                         ' Tasterabfrage an diesem Port
waitms 200

 If Switch = 1 Then ' Call Bootloader if switch is pressing by power-on
  goto &h1000 ' goto &h800 also wont work **
 End If

do

' Here my Mainprogramm

loop


I cant call the Bootloader! Also i tried to force a uC-Reset with WatchDog.
**In the BASCOM-Prog is the Bootloader at $800 (Fusebit High KL 00:Bootsize 2048 words at $800) but the Bootloader starts at &H1000.


FBH: 1: Reset vector is $0000
FBExt: 0:Hardwareboot enabled.

I Also tried Reset vector is bootloader
Hardwareboot disabled


(BASCOM-AVR version : 2.0.8.1 )
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MWS

Bascom Member



Joined: 22 Aug 2009
Posts: 1830

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PostPosted: Sat Mar 10, 2018 1:31 pm    Post subject: Re: Starting Bootloader from Application Reply with quote

Alex20q90 wrote:
i have a new problem!
That was to expect.
I thought about helping you through, but considering your previous thread, your low discussion ability and low esteem about other discussion partners as devote helpsters, I do not think I would enjoy it much.
Also I regularly find it arrogant if persons formerly seeking help just leave after their question was answered, while giving a damn about others getting stuck by trying to find out the final result of a thread. You seem to be such a self-centered candidate.
Ok, ranted that, now just a hint:
Quote:
LUFA Bootloader
...
i tried to force a uC-Reset with WatchDog.

That's the suggested process by the LUFA library for AVR.
It surly works, if not for you then because you did it wrong.
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Evert :-)

Bascom Expert



Joined: 18 Feb 2005
Posts: 2117

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PostPosted: Sat Mar 10, 2018 3:59 pm    Post subject: Reply with quote

Hi,

Goto &Hxxx should work,
However &H1000 is not a valid Bootloader address, what is valid depends on how big your bootloader loader is, have a look at the datasheet page 239.

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www.evertdekker.com Bascom code vault
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Alex20q90

Bascom Member



Joined: 24 Sep 2007
Posts: 89

germany.gif
PostPosted: Sat Mar 10, 2018 6:05 pm    Post subject: Re: Starting Bootloader from Application Reply with quote

Evert Smile wrote:
Hi,

Goto &Hxxx should work,
However &H1000 is not a valid Bootloader address, what is valid depends on how big your bootloader loader is, have a look at the datasheet page 239.


Thanks Evert!
I read it in the past and i tried this to start my bootloader with this adress, after it did not work i look onto the programmers buffer who looks like it starts by $1000. Maybe i give up to early with $800.

EDIT: i tried the adress $800 (&h0800) but i cant call the bootloader.
Also tried with restart by Watchdog!

Now i see in the documentation of LUFA

http://www.fourwalledcubicle.com/files/LUFA/Doc/120219/html/_page__software_bootloader_start.html

that it use a "Magic_Key".
In my case it is in the Bootloadeer with

Code:
#define MAGIC_BOOT_KEY           0xDC42


and in the App i have to start with (example)


Code:
  void Jump_To_Bootloader(void)
  {
      // If USB is used, detach from the bus and reset it
      USB_Disable();

      // Disable all interrupts
      cli();

      // Wait two seconds for the USB detachment to register on the host
      Delay_MS(2000);

      // Set the bootloader key to the magic value and force a reset
      Boot_Key = MAGIC_BOOT_KEY;
      wdt_enable(WDTO_250MS);
      for (;;);
  }


But the Magic_key have to written in the Memory! But i cant find the place of adress where its have to been written!






MWS wrote:
Alex20q90 wrote:
i have a new problem!
That was to expect.


MWS wrote:
It surly works, if not for you then because you did it wrong.


d'oh!
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