LPC812 - placing data on specific address in flash

vojtechhavlicek · ‎01-30-2018

Hi,

I need to place specific data (default values which could be changed via IAP) into specific address on flash when I program the MCU.

I found cr_section_macros.h - Placing code/rodata into different FLASH blocks

There is macro

#define __RODATA_EXT(bank,name) __SECTION_EXT(rodata, bank, name)

It´s ok but there is no option to define specific address where the data will be placed.

Is there any option/approach How I can complete this task?

Is it possible to create variable in flash somehow via pointer?

There is another solution which could work but I would prefer something which is easier...

Defining Variables at Absolute Addresses with gcc | MCU on Eclipse

kerryzhou · ‎02-08-2018

Hi vojtech havlicek,

If you want to change it in the future, you still can add the flash IAP function to modify that flash area.

Have a great day,
Kerry

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在原帖中查看解决方案

kerryzhou · ‎01-31-2018

Hi vojtech havlicek,

I don't know what the data type you want to write it in the flash.

Do you want to define some constant data in the flash, and you don't need to modify it in the code?

If yes, you can use these ways, just like the method in your :

Defining Variables at Absolute Addresses with gcc | MCU on Eclipse

1. IAR

Define the constant data in flash address 0x10000000, the detail address you can modified it by your own solution.

#pragma location = 0x10000000

__root const char Data_config[] = {…}；

take an example:

#pragma location = 0x10000000

__root const char Data_config[] = //@ ".intvec" =

{

0x0,0x1,0x2,0x3,0x4,0x5,0x6,0x7,0x8,0x9,0xA,0xB,0xC,0xD,0xE,0xF,

0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,

0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,

0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,

0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,

0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F,

0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,

0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,

0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,

0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,

0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,

0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,

0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0xCC,0xCD,0xCE,0xCF,

0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,

0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,

0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF

};

2. MDK

Define the constant data in flash address 0x10000000, the detail address you can modified it by your own solution.

const char Data_config[] __attribute__((at(0x10000000))) ={…};

take an example:

const char Data_config[] __attribute__((at(0x10000000))) =