Development environment:
- Code Warrior IDE version 5.9.0
I am developing using the MPC5674F. The target board is equipped with external memory (SRAM).
In order to allocate all program variable data to external memory (SRAM), I modified the code in the LCF file as follows:
* File name : MPC5674F_MVx264.lcf
MEMORY
{
......
// Add External Memory area
EXSRAM : org = 0x20000000, len = 0x001FFFFF
}
SECTIONS
{
......
// Delete program data allocation default code
/*
GROUP : {
.__uninitialized_intc_handlertable ALIGN(20) : {}
.data : {}
.sdata : {}
.sbss : {}
.sdata2 : {}
.sbss2 : {}
.bss : {}
} > internal_ram
*/
// Add program data allocation code
GROUP : {
.__uninitialized_intc_handlertable ALIGN(20) : {}
.data : {}
.sdata : {}
.sbss : {}
.sdata2 : {}
.sbss2 : {}
.bss : {}
} > EXSRAM
.......
......
}
And then, I modified the code to do setting EBI (External BUS Interface) as follows.
* File name : __PPC_eabi_init.c
asm void __init_user(void)
{
.....
.....
// Call SetExternalBusInterface() function for External Bus Interface initialization
bl SetExternalBusInterface
frfree
blr
}
After, The build was done well and I confirmed that variables are allocated in the external memory (SRAM) using the debugger and map file.
However, the variable values was not initialized and the garbage value was stored.
I want to know what's wrong.
How to normally allocate all program variable data to external memory?
