Hello!
I'd like to know how to properly configure startup sequence, link and boot the application, that is getting loaded into the RAM trough the communication interface (UART, ETH, etc...)
For my usecase I want to implement my custom bootloader so that allows me to load an application directly to the ram and jump into application entry point.
I changed the linker and moved my app's entry point to 0x701B0000 so I can load the hello world app from that address. The "hello world" application boots and works, but it crashes once it triggers an interrupt.
For my understanding something goes wrong with vector tables and I can't find the information how to properly configure them. Please guide me how to configure startup sequence and setup vector tables for my case.
Looking forward for reply
/* This is the stack that is used by code running within main()
* In case of NORTOS,
* - This means all the code outside of ISR uses this stack
* In case of FreeRTOS
* - This means all the code until vTaskStartScheduler() is called in main()
* uses this stack.
* - After vTaskStartScheduler() each task created in FreeRTOS has its own stack
*/
--stack_size=16384
/* This is the heap size for malloc() API in NORTOS and FreeRTOS
* This is also the heap used by pvPortMalloc in FreeRTOS
*/
--heap_size=32768
-e_vectors /* This is the entry of the application, _vector MUST be plabed starting address 0x0 */
/* This is the size of stack when R5 is in IRQ mode
* In NORTOS,
* - Here interrupt nesting is enabled
* - This is the stack used by ISRs registered as type IRQ
* In FreeRTOS,
* - Here interrupt nesting is enabled
* - This is stack that is used initally when a IRQ is received
* - But then the mode is switched to SVC mode and SVC stack is used for all user ISR callbacks
* - Hence in FreeRTOS, IRQ stack size is less and SVC stack size is more
*/
__IRQ_STACK_SIZE = 256;
/* This is the size of stack when R5 is in IRQ mode
* - In both NORTOS and FreeRTOS nesting is disabled for FIQ
*/
__FIQ_STACK_SIZE = 256;
__SVC_STACK_SIZE = 4096; /* This is the size of stack when R5 is in SVC mode */
__ABORT_STACK_SIZE = 256; /* This is the size of stack when R5 is in ABORT mode */
__UNDEFINED_STACK_SIZE = 256; /* This is the size of stack when R5 is in UNDEF mode */
SECTIONS
{
/* This has the R5F boot code until MPU is enabled, this MUST be at a address < 0x80000000
* i.e this cannot be placed in DDR
*/
GROUP {
.vectors:{} palign(8)
.text.hwi: palign(8)
.text.cache: palign(8)
.text.mpu: palign(8)
.text.boot: palign(8)
.text:abort: palign(8) /* this helps in loading symbols when using XIP mode */
.text: {} palign(8) /* This is where code resides */
.rodata: {} palign(8) /* This is where const's go */
.data: {} palign(8) /* This is where initialized globals and static go */
.bss: {} palign(8) /* This is where uninitialized globals go */
RUN_START(__BSS_START)
RUN_END(__BSS_END)
.sysmem: {} palign(8) /* This is where the malloc heap goes */
.stack: {} palign(8) /* This is where the main() stack goes */
.irqstack: {. = . + __IRQ_STACK_SIZE;} align(8)
RUN_START(__IRQ_STACK_START)
RUN_END(__IRQ_STACK_END)
.fiqstack: {. = . + __FIQ_STACK_SIZE;} align(8)
RUN_START(__FIQ_STACK_START)
RUN_END(__FIQ_STACK_END)
.svcstack: {. = . + __SVC_STACK_SIZE;} align(8)
RUN_START(__SVC_STACK_START)
RUN_END(__SVC_STACK_END)
.abortstack: {. = . + __ABORT_STACK_SIZE;} align(8)
RUN_START(__ABORT_STACK_START)
RUN_END(__ABORT_STACK_END)
.undefinedstack: {. = . + __UNDEFINED_STACK_SIZE;} align(8)
RUN_START(__UNDEFINED_STACK_START)
RUN_END(__UNDEFINED_STACK_END)
.ARM.exidx: {} palign(8) /* Needed for C++ exception handling */
.init_array: {} palign(8) /* Contains function pointers called before main */
.fini_array: {} palign(8) /* Contains function pointers called after main */
} > OCRAM
}
MEMORY
{
/*R5F_VECS : ORIGIN = 0x701B0000 , LENGTH = 0x00000040*/
/*R5F_TCMA : ORIGIN = 0x00000040 , LENGTH = 0x00007FC0*/
/*R5F_TCMB : ORIGIN = 0x00080000 , LENGTH = 0x00008000*/
/* when using multi-core application's i.e more than one R5F/M4F active, make sure
* this memory does not overlap with other R5F's
*/
OCRAM : ORIGIN = 0x701B0000 , LENGTH = 0x40000
/* This section can be used to put XIP section of the application in flash, make sure this does not overlap with
* other CPUs. Also make sure to add a MPU entry for this section and mark it as cached and code executable
*/
FLASH : ORIGIN = 0x60100000 , LENGTH = 0x80000
}
