# Relocating Interrupt vector to an address in ROM crashes the FW **URL:** \ **Category:** Libraries\ **Created:** [February 16, 2024, 7:21pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202 "2024-02-16T19:21:03Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![jaink](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jaink](https://forums.freertos.org/u/jaink)\ **Post date:** [February 16, 2024, 7:21pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/1 "2024-02-16T19:21:04Z")
I am trying to relocate my Interrupt vector from 0x8000000 to 0x8010000. I start the code in debugger and after calling SystemInit, I set the address manually in VTOR in Register window. The program runs fine. But if I call a routine to set VTOR register then program crashes. Here is my routine: \_\_WEAK void SystemVTORSetup(void) { /\* relocate vector table \*/ \_\_disable\_irq(); SCB-\>VTOR = (uint32\_t)(&\_\_Vectors); \_\_DSB(); \_\_enable\_irq(); } Any help will be highly appreciated Thanks ---
**Author:** ![hs2](https://avatars.discourse-cdn.com/v4/letter/h/a4c791/32.png) [@hs2](https://forums.freertos.org/u/hs2)\ **Post date:** [February 16, 2024, 7:33pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/2 "2024-02-16T19:33:53Z")
Do you call it as early as possible means BEFORE any interrupt/exception might occur ? You could set a breakpoint there and run the application to see if you even reach the code adjusting VTOR. `__disable/enable_irq();` doesn’t really help as this function must be invoked before any interupt is enabled. Usually VTOR adjustment is done in the `Reset_Handler` before branching to `main()`. ---
**Author:** ![jaink](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jaink](https://forums.freertos.org/u/jaink)\ **Post date:** [February 16, 2024, 7:37pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/3 "2024-02-16T19:37:53Z")
I am calling my routine to change the value in VTOR inside main, after systemInit(), but before my application runs. If changing it manually, this is the place I change manually in the Reg window as well. Yes, I can put the breakpoint at the code that changes the VTOR value and I see it being changed correctly in the Register window in the debugger ---
**Author:** ![hs2](https://avatars.discourse-cdn.com/v4/letter/h/a4c791/32.png) [@hs2](https://forums.freertos.org/u/hs2)\ **Post date:** [February 16, 2024, 7:43pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/4 "2024-02-16T19:43:12Z")
So you can step thru the adjustment function (with interrupts not yet enabled due to MCU reset) and verify the properly changed VTOR value in the debugger ? When does the app crash ? ---
**Author:** ![jaink](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jaink](https://forums.freertos.org/u/jaink)\ **Post date:** [February 16, 2024, 7:43pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/5 "2024-02-16T19:43:47Z")
The app crashes when it tries to start the first task ---
**Author:** ![hs2](https://avatars.discourse-cdn.com/v4/letter/h/a4c791/32.png) [@hs2](https://forums.freertos.org/u/hs2)\ **Post date:** [February 16, 2024, 7:47pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/6 "2024-02-16T19:47:02Z")
Hmm … that’s a most likely a completely different issue you should have told earlier. Standard question is (in case you start using FreeRTOS): Did you define `configASSERT` and enable [stack checking](https://www.freertos.org/Stacks-and-stack-overflow-checking.html) for development ? This usually helps a lot to find out and fix initial issues running a FreeRTOS application. Which FreeRTOS version and which MCU do you use ? And do you know the valuable [FreeRTOS FAQ - links to all RTOS FAQ pages](https://freertos.org/FAQ.html) ? ---
**Author:** ![jaink](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jaink](https://forums.freertos.org/u/jaink)\ **Post date:** [February 16, 2024, 7:49pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/7 "2024-02-16T19:49:38Z")
I will give it another try to the FAQ link. Will investigate the StackChecking as well. Thanks for the pointers. In my opinion, the issue is the Vector address. Because if I dont change the vector address then everything is good. ---
**Author:** ![hs2](https://avatars.discourse-cdn.com/v4/letter/h/a4c791/32.png) [@hs2](https://forums.freertos.org/u/hs2)\ **Post date:** [February 16, 2024, 8:36pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/8 "2024-02-16T20:36:00Z")
Well, the address of your vector/exception table `__vectors` can be verified in the map file (output file of the linker). If the vector table is copied into RAM the address is different of course. ---
**Author:** ![jaink](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jaink](https://forums.freertos.org/u/jaink)\ **Post date:** [February 16, 2024, 9:30pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/9 "2024-02-16T21:30:54Z")
Yes, I have verified it in the map file and it is correct. The Vector table is not relocated in RAM. It is still in ROM ---
**Author:** ![htibosch](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/htibosch/32/62_2.png) [@htibosch](https://forums.freertos.org/u/htibosch)\ **Post date:** [February 17, 2024, 4:49am UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/10 "2024-02-17T04:49:41Z")
When I work with STM32F[47], the bootloader will use `0x0800000`, and put the vector table there. What platform do you use? For the application, which starts at eg. `0x08010000`, I copy the vector table to SRAM, and have `SCB->VTOR` point to the first byte in SRAM. And also I have to configure `SYSCFG->MEMRMP` to remap SRAM. Note that the method is different in STM32F4 and STM32F7. - F4: the vectors are copied to `0x20000000` (SRAM), and address 0x0 is remapped to SRAM (MEMRMP=3). - F7: `SCB->VTOR` is set to point to SRAM (MEMRMP=0) Here is some code that I used: [remap\_vtor\_table\_to\_ram.zip](https://forums.freertos.org/uploads/short-url/pS7U5QbT1XZgbieIWl79Tnqm4d4.zip) (877 Bytes) I’m not sure if it applies to your platform too. ---
**Author:** ![RAc](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/rac/32/1389_2.png) [@RAc](https://forums.freertos.org/u/RAc)\ **Post date:** [February 17, 2024, 8:09am UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/11 "2024-02-17T08:09:07Z")
Can we see your map and linker command files? What platform are you using? ---
**Author:** ![jaink](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jaink](https://forums.freertos.org/u/jaink)\ **Post date:** [February 17, 2024, 1:08pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/12 "2024-02-17T13:08:22Z")
Thanks for your help. Really appreciate it. It seems that my setup had some other issues. It runs good now. Thanks again ---
**Author:** ![jaink](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jaink](https://forums.freertos.org/u/jaink)\ **Post date:** [February 17, 2024, 1:09pm UTC](https://forums.freertos.org/t/relocating-interrupt-vector-to-an-address-in-rom-crashes-the-fw/19202/13 "2024-02-17T13:09:32Z")
Thank you for sharing the code. Appreciate it. It will certainly be very helpful if we decide to move the table to RAM