In my Cortex-M0 project, there are two program images residing at different memory locations: 0x0000_0000 and 0x0010_0000. Each program has its own vector table. M0 will boot from the program at 0x0010_0000 then switch to the other program (0x0000_0000) at the end.
What is the correct way to switch to the porgram at 0x0000_0000? I'm not sure whether the following instructions are correct or not.
LDR R6, =0x1 ; set R6 to 0x0000_0001 due to Thumb mode
LDR R0, [R6]
MOV SP, R0
LDR R1, [R6, #4]
Can someone please point me the right implementation? Thanks a lot.
You would need to change the linker ROM start for each application, so they all get their own vector table (below tested for M0+)Can take a couple of short cuts as M0 probably will have less than 64K of flash,and you compile to 1K boundary.
if ( firm1 > firm2) __asm("movs r0, #0x40"); // upper byte for firmware at 0x4000else __asm("movs r0, #0xA0"); // upper byte for firmware at 0xA000
__asm("lsls r0, r0, #8");
__asm("ldr r1, [r0]");
__asm("msr msp, r1"); // Set new MSP
__asm("msr psp, r1"); // PSP based on SP
__asm("ldr r1, [r0,#0x4]");
__asm("mov pc, r1"); // Jump by changing PC
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