Hello,
I started an MPC5668G project where during startup, I need to copy a portion of code from ROM=>RAM. I want the code to be compiled as beeing part of RAM but located in ROM (so that it can be flashed in non volatile memory).
I say compiled as "part of RAM" because the .elf file should contain RAM located debuging symbols so that when I run the code on a demo board, I can see the high level source at the right place in the RAM.
Here is part of my lcf file content:
MEMORY {
/* section allocation */
applvect_fromCan: org = 0x10000, len = 0x08
romfbl: org = 0x00010008, len = 0x0001FFF0
/* ROM 2M*/
rom2: org = 0x00012000, len = 0x001EE000
/* Code and data to external RAM */
ram: org = 0x40004000, len = 0x32000
/* Stack at top of external RAM */
stack: org = 0x40036000, len = 0x2000
/* FLASHDRV */
flashdrv: org = 0x40000000, len = 0x1000
/* Vectors allocated to external RAM */
vec: org = 0x40038000, len = 0x2000
eth: org = 0x40001000, len = 0x3000
}
SECTIONS {
/* The first group contains code and constant data */
/* The second group will allocate space for the initialized data
* (.data/.sdata) and the unititialized data (.bss/.sbss)
*/
GROUP : {
EEPDATA (BSS) : {}
__DATA_RAM = .;
.data (DATA) LOAD(__DATA_ROM) : { *(.data) }
.sdata (DATA) LOAD(ADDR(.sdata) - ADDR(.data) + __DATA_ROM) : { *(.sdata) }
.sbss (BSS) : {}
.bss (BSS) : {}
.osdata (DATA): {}
.ossdata (DATA): {}
__DATA_RAM_START = .;
RAMCODE (VLECODE) LOAD(__TEXT_ROM) :
{
*(.text)
}
.sdata2 (TEXT) LOAD(ADDR(.sdata2) - ADDR(RAMCODE) + __TEXT_ROM) :
{
*(.sdata2)
}
__DATA_RAM_END = .;
} >ram
GROUP : {
APPLVECT_FROMCAN (DATA) : {}
} > applvect_fromCan
GROUP : {
.text1(VLECODE) : {*(.text_vle)}
FBLHEADER (DATA) : {}
/* This is a dummy section to satisfy the linker for vle!*/
/* This section should not contain any code. */
.text_e (TEXT) : {
*(.text)
. = (.+15) & ~15;
}
.ctors : {}
.dtors : {}
.oscode (TEXT) : {}
.osconst (CONST) : {}
.ossconst (CONST) : {}
.osstring (CONST) : {}
APPLVECT (DATA) : {}
FLASHROM (DATA) : {}
__TEXT_ROM = .;
}
} > romfbl
The problem is that when I open the generated .hex file, the code corresponding to the .text sections is in the RAM (adresses from 0x40004000) and not in ROM. I expected the code beeing located at __TEXT_ROM address and a free space in RAM from address 0x40004000.
What is wrong with the lcf file?
Thanks a lot.
P.SCHMIDT
