This is a follow up to some other posts about getting around errate e2448 (which should be posted everywhere and is extremely nasty!!)
about 9 months I got a solution from support that I posted that never really worked right.
I have a much simpler solution now. See Attached.
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A two step solution
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1.) At the *(.relocate_code) to the linker command file in the .app_data section right after *(.data). This will allow one to locate functions in the initialized data section (i.e. at startup stuff in this area is copied from init values in the flash.
.app_data: AT(___ROM_AT)
{
* (.sdata)
* (.data)
*(.relocate_code) <<<<<<<<
.= ALIGN(0x4) ;
*(.ARM.extab)
1.) .= ALIGN(0x4) ;
2.) A couple useful Macros:
#pragma define_section relocate_code ".relocate_code" ".relocate_code" ".relocate_code" far_abs RX
#define __relocate_code__ __declspec(relocate_code)
3.)Use the __relocate_code__ macro infront the function delclarations
_relocate_code__ void InitClock()
{
// If the internal load capacitors are being used, they should be selected
// before enabling the oscillator. Application specific. 16pF and 8pF selected
// in this example
OSC_CR = OSC_CR_SC16P_MASK | OSC_CR_SC8P_MASK;
// Enabling the oscillator for 8 MHz crystal
// RANGE=1, should be set to match the frequency of the crystal being used
// HGO=1, high gain is selected, provid
..
..
.
4.) Compile for FLASH and check the linker map. You will notice that there is a function of size 0xF2 in the .App_data section:
# .app_data
1FFF8000 0000000F .data @67 (main.obj)
1FFF800F 00000001 .data @400 (libc_Thumb_LE_v7M.a printformat_.o )
1FFF8010 000000F2 .relocate_code InitClock (Clock.obj)
I just tested this with the K40 tower board.
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One less step
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Also note that you should be able to change the
#pragma define_section relocate_code ".relocate_code" ".relocate_code" ".relocate_code" far_abs RX
To
#pragma define_section relocate_code ".data" ".data" ".data" far_abs RX
And not have to change the linker file. This makes it possible to relocate code without a special linker file.
-Eli
