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Why to relocate the vector table?
If your target’s doesn’t have such feature and the vector table is in the bootloader are 0x0000 to 0x8000 then you will need to relocate the vector table for the application so that an interrupt occurring in the application results in jumping to the correct handler.
What is vector table relocation?
While the interrupt vector table is located at the start of memory when the Cortex-M processor is reset, it is possible to relocate the vector table to a different location in memory. The vector table can be relocated by writing to a register in the SCB called the vector table offset register.
What is vector table in bootloader?
The Interrupt table for the MSP430 is held in FLASH and so cannot be modified easily. It also holds the reset vector that must always point to the start of the bootloader code so erasing and rewriting this area runs the risk of completely bricking the unit.
What is difference between IDT and IVT?
It’s the CPU’s structures, which the OS initializes to handle interrupts and exceptions. In the real addressing mode the structure just contains addresses of ISRs. This format of it is known as IVT. In the protected mode the structure is more complex and is called IDT.
Where is IVT stored?
1 Answer. On a PC the interrupt vector table (IVT) is always located in RAM. By default it’s located at 0000:0000 at the start of memory, but it’s possible to move it using the LIDT instruction.
What types of descriptors are stored in IDT?
Use of the IDT is triggered by three types of events: hardware interrupts, software interrupts, and processor exceptions, which together are referred to as interrupts. The IDT consists of 256 interrupt vectors–the first 32 (0–31 or 0x00–0x1F) of which are used for processor exceptions.
What are interrupts and its types?
TYPES OF INTERRUPTS Maskable Interrupt: The hardware interrupts which can be delayed when a much highest priority interrupt has occurred to the processor. Non Maskable Interrupt: The hardware which cannot be delayed and should process by the processor immediately.
How to jump from bootloader to vector table?
At startup or a hardware reset, the hardware will initialize the Vector Table Offset Register to 0x00000000, set the stack pointer to the first value in the vector table, and then jump to the location given in the second entry in the table. But when you jump from a bootloader to the application, you have to do each of those things yourself.
Do you have to relocate your vector table?
Yes – you have to relocate your vector table, otherwise the interrupts will fire handlers of the bootloader, which will almost certainly lead to a crash.
Where to find the vector table in arm?
By default, on ARM cores, the vector table is found at the very beginning of your application binary. The first entry will be the initial stack pointer, and the second entry will be the reset vector (the application entry point). The rest of the entries are defined by the specific ARM architecture as well as the specific implementation.
How are the entries in the vector table defined?
The rest of the entries are defined by the specific ARM architecture as well as the specific implementation. At startup or a hardware reset, the hardware will initialize the Vector Table Offset Register to 0x00000000, set the stack pointer to the first value in the vector table, and then jump to the location given in the second entry in the table.