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[avr-gcc-list] VMA & LMA address -- confused ?
From: |
Dinesh Guleria |
Subject: |
[avr-gcc-list] VMA & LMA address -- confused ? |
Date: |
Thu, 9 Dec 2010 15:57:44 +0530 |
Hi,
I am bit confused about VMA & LMA address for AVR.
Virtual memory address & Load Memory Address.
1> What actually does it means ???????
What i got from reading is that VMA is passed to linker & .ELF is created.
While avr-objcopy read .elf & creats the .hex in this hex file .crt code will place the data variable to LMA.
& .eep file in this file epprom variables are placed to LMA.
Because of harvard architectue to avoid confusion related to memory address ( because EEPROM, RAM & Flash all will start from 0x0000 i.e ZERO address) GCC does following :---
Add 0x800000 the to real SRAM --- if you want the .data section to start at 0x1100, pass 0x801100 at the address
Add 0x810000 the to real EEPROM
2> What does it add for the ROM address, i am bit confused --- ????????
3> Also why this typical number series are chosen 0x800000 .... ???????
This operation produces VMA. This is only my understanding & assumption.
Please correct me for the above three question.
BR
- [avr-gcc-list] VMA & LMA address -- confused ?,
Dinesh Guleria <=