I have a function table type defined like so
typedef struct
{
uint16_t majorRevision;
uint16_t minorRevision;
uint8_t (*CommInit)(void *);
uint8_t (*CommDeInit)(void);
uint16_t (*Write)(uint8_t *, uint16_t);
uint16_t (*Read)(uint8_t *, uint16_t);
uint8_t (*Attached)(void);
uint8_t (*ExitApp)(uint8_t);
uint8_t (*Jump)(uint32_t address);
uint16_t (*GetCRC)(uint8_t*, uint32_t);
int (*Encrypt)(uint8_t *, uint32_t);
int (*Decrypt)(uint8_t *, uint32_t);
uint8_t (*Reset)(void);
uint32_t (*GetTickCount)(void);
void (*Sleep)(uint32_t);
uint8_t (*ReadASCIIByte)(void);
uint16_t (*ReadASCIIWord)(void);
uint32_t (*ReadASCIIDWord)(void);
void (*WriteASCIIByte)(uint8_t);
void (*WriteASCIIWord)(uint16_t);
void (*WriteASCIIDWord)(uint32_t);
void (*PutChar)(uint8_t);
uint8_t (*GetChar)(void);
uint8_t (*WaitChar)(uint8_t *, uint32_t);
uint8_t (*IsOpen)(void);
} BootFunctionTable_t;
Then I declare a variable of that type using the default_function_attribute pragma to force it to a specific address and fill it with my specific functions.
#pragma default_variable_attributes = @ "boottable"
BootFunctionTable_t bootFunctions =
{
MAJOR_REVISION,
MINOR_REVISION,
BootSerialInit, /* Communication Init */
BootSerialDeInit, /* Communication Deinit */
BootSerialWrite,
BootSerialRead,
BootSerialAttached,
BootExitToApp,
BootJump,
BootGetCRC,
NULL,
NULL,
BootReset,
BootGetTickCount,
BootSleep,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
BootSerialPutChar,
BootSerialGetChar,
NULL
};
#pragma default_variable_attributes =
In main I create a new pointer and point it to the address of where I attempted to force this table
BootFunctionTable_t * bootf;
bootf = (BootFunctionTable_t *)0x080000200;
Finally, I create the section in my linker file
/*###ICF### Section handled by ICF editor, don't touch! ****/
/*-Editor annotation file-*/
/* IcfEditorFile="$TOOLKIT_DIR$\config\ide\IcfEditor\cortex_v1_0.xml" */
/*-Specials-*/
define symbol __ICFEDIT_intvec_start__ = 0x08000000;
/*-Memory Regions-*/
define symbol __ICFEDIT_region_ROM_start__ = 0x08000300;
define symbol __ICFEDIT_region_ROM_end__ = 0x080FFFFF;
define symbol __ICFEDIT_region_RAM_start__ = 0x20000000;
define symbol __ICFEDIT_region_RAM_end__ = 0x2001FFFF;
define symbol __ICFEDIT_region_CCMRAM_start__ = 0x10000000;
define symbol __ICFEDIT_region_CCMRAM_end__ = 0x1000FFFF;
/*-Sizes-*/
define symbol __ICFEDIT_size_cstack__ = 0x400;
define symbol __ICFEDIT_size_heap__ = 0x200;
/**** End of ICF editor section. ###ICF###*/
define memory mem with size = 4G;
define region ROM_region = mem:[from __ICFEDIT_region_ROM_start__ to __ICFEDIT_region_ROM_end__];
define region RAM_region = mem:[from __ICFEDIT_region_RAM_start__ to __ICFEDIT_region_RAM_end__];
define region CCMRAM_region = mem:[from __ICFEDIT_region_CCMRAM_start__ to __ICFEDIT_region_CCMRAM_end__];
define region BOOTTABLE_region = mem:[from 0x08000200 to 0x080002FF];
initialize by copy {section boottable};
place in BOOTTABLE_region { readonly section boottable};
define block CSTACK with alignment = 8, size = __ICFEDIT_size_cstack__ { };
define block HEAP with alignment = 8, size = __ICFEDIT_size_heap__ { };
initialize by copy { readwrite };
do not initialize { section .noinit };
place at address mem:__ICFEDIT_intvec_start__ { readonly section .intvec };
place in ROM_region { readonly };
place in RAM_region { readwrite,
block CSTACK, block HEAP };
But I can't the linker to place bootFunctions at the requested address. Can someone please tell me what I am doing wrong? I can't even get the section to show up in the map file. The only example I can find of this is the .intvec section but the vector table is defined in an assembly file. I would like to place my boottable in a C file.
Symbols that are not used are excluded by the linker.
Try to explicitly tell linker to keep the section. Add a line like:
keep { section boottable };
@user694733 is correct. Because I wasn't actually using
BootFunctionTable_t bootFunctions
but rather the hardcoded address the linker was leaving it out. I changed the code to
BootFunctionTable_t * bootf;
bootf = &bootFunctions;
and that also fixed it.
I have to say that I couldn't get the 'keep' linker instruction to work for me. What I did find was the IAR note 51348 https://www.iar.com/support/tech-notes/linker/the-linker-removing-functions-and-variables-or-external-not-found/ which suggests using __root to force the linker to keep stuff, and that worked for me.
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