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Zephyr project on STM32

   Zephyr Workbench, a VSCode extension to manage Zephyr on STM32.
It enables users to easily create, develop, and debug Zephyr applications.
Main features:
  • Install host dependencies.
  • Import toolchain and SDK.
  • Create, configure, build and manage apps.
  • Debug STM32.
You can directly download it from the VSCode marketplace
For more details, visit the Zephyr Workbench

System Workbench for STM32

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You are viewing a reply to Change application on Reset !  

Change application on Reset !

Posted by thomasfuture on 2018-05-28 14:04

Hi Tarek,

Yes, each applications have its Reset Handler, but maybe this is not the way to do this, if you can help me on this it’s will be cool.

Regards

Reads: 1820
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Posted by tarek bouchkati on 2018-05-28 14:12 Tunisia

In that case, this could be a solution : 

SwapApp:
  ldr r0, =0x08019F40
  bx  r0

Reset_Handler:  
  /* boot swap management */
  ldr r0, =0x20000270
  ldr r1, =0xFEED0001
  ldr r2, [r0]
  cmp r1, r2
  bne SwapApp
  /* end of boot swap management */

  ldr   sp, =_estack      /* set stack pointer */
  ........
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Posted by thomasfuture on 2018-05-28 15:26

So, if I follow what’s you saids, I don’t need to touch to SP et PC ?


I try with your code, but without success, or only half !

When I do a Reset, I switch from App1 to App2 but afterthe program loop in main of App2..

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Posted by tarek bouchkati on 2018-05-28 16:08 Tunisia

I’ve tested the solution without issues.
So, I will share with you a complete example tomorrow :-)

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Posted by thomasfuture on 2018-05-28 16:58
Thanks Tarek because I didn’t see the issue here..
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Posted by tarek bouchkati on 2018-05-28 22:57 Tunisia

Look, while driving home, I have remembered that STM32L072CZ has dual bank boot capability, so this could be achieved by changing dynamically the the BFB2 option bit.
This could be a cutting edge solution !

Back to the first one, the pb could be that we jumbed directly to the App2’ main.
So, could you verify that 0x08019F40 is really the App2 Reset Handler Address ?

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Posted by thomasfuture on 2018-05-29 09:20

App2 address is now 0x08018000 (not 0x08019F40), and 0x08018000 it’s first address of bank 1.

From .map file :

.text.Reset_Handler
0x08023534 0x50 Projects/SW4STM32/startup_stm32l072xx.o
0x08023534 Reset_Handler

So we need to jump to 0x08023534, in order to init memory, system and go to main.

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Posted by tarek bouchkati on 2018-05-29 12:40 Tunisia

In that case : 

SwapApp:
  ldr r0, =0x08023534
  bx  r0

Reset_Handler:  
  /* boot swap management */
  ldr r0, =0x20000270
  ldr r1, =0xFEED0001
  ldr r2, [r0]
  cmp r1, r2
  bne SwapApp
  /* end of boot swap management */

  ldr   sp, =_estack      /* set stack pointer */
  ........
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Posted by thomasfuture on 2018-05-29 14:03

In cortex M0+ it’s not BNE but BEQ

-> Suffix : EQ Flags : Z = 1 Meaning : Equal, last flag setting result was zero.

From The STM32L0 Cortex-M0+ instruction set :-)

So made this :

/* boot swap management */

ldr r4, =0x20000000 //load address of the value stored in .c
ldrb r5, r4 //load in r5 value stored in .c
ldr r6, =0xFEED0001 //to compare
cmp r5, r6 //compare value from .c (store in RAM) to r6 (fixed value)
beq SwapApp //if equal Reboot from App2
/* end of boot swap management */


ldr r0, =_estack
mov sp, r0 /* set stack pointer */
/* Copy the data segment initializers from flash to SRAM */
movs r1, #0

b LoopCopyDataInit

SwapApp:
ldr r0, =0x08023534
bx r0

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