m_flash_config address

[davesturgess]

Above the end of the interrupt vectors (0x01FF) there is an unused flash memory region of 0x0200 bytes after which m_flash_config is defined. Is it possible to relocate m_flash_config to 0x0200 to make use of this unused flash memory.

m_interrupts (RX) : ORIGIN = 0x00000000, LENGTH = 0x00000200

m_flash_config (RX) : ORIGIN = 0x00000400, LENGTH = 0x00000010
m_text (RX) : ORIGIN = 0x00000410, LENGTH = 0x0001FBF0
m_data (RW) : ORIGIN = 0x1FFFE000, LENGTH = 0x00008000 

I have tried but it does not seem to work.

Thanks

Dave

[davesturgess]

Hi Earl

Thank you for your reply, I thought that was the case but hoped there was a work around. Yes I could force something there, is there a way to make the linker use this area automatically as an extension of the "m_text" memory? I tried the following and other options which seemed logical but the linker did not like them.

/* Specify the memory areas */

MEMORY

{

m_interrupts (RX) :       ORIGIN = 0x00000000, LENGTH = 0x00000200

m_text (RX) :                ORIGIN = 0x00000200, LENGTH = 0x00000200       <ADDED

m_flash_config (RX) :   ORIGIN = 0x00000400, LENGTH = 0x00000010

m_text2 (RX) :              ORIGIN = 0x00000410, LENGTH = 0x0001FBF0

m_data (RW) :              ORIGIN = 0x1FFFE000, LENGTH = 0x00008000

}

/* The program code and other data goes into internal flash */

.text :

{

. = ALIGN(4);

*(.text) /* .text sections (code) */

*(.text*) /* .text* sections (code) */

*(.rodata) /* .rodata sections (constants, strings, etc.) */

*(.rodata*) /* .rodata* sections (constants, strings, etc.) */

*(.glue_7) /* glue arm to thumb code */

*(.glue_7t) /* glue thumb to arm code */

*(.eh_frame)

KEEP (*(.init))

KEEP (*(.fini))

. = ALIGN(4);

} > m_text

It reads like the linker can concatenate ".text" sections.

Thanks again

Dave

[egoodii]

Sorry, the linker is not going to be 'smart enough' to find the 'best fit' for a 'random size block' for you.  It can concatenate resources to a 'larger contiguous chunk', but will not like 'non-contiguous'.

[davesturgess]

Hi Earl

Thanks for that information, you have saved me a lot of time trying.

Best regards

Dave

[egoodii]

The short answer is 'no'.  The addresses '0' and '0x400' are interpreted by hardware at startup, and cannot be moved.  Find something 'else' to fill this little hole with!