Re: Increasing bss section in Zephyr


Andy Ross
 

Sukumar Ghorai wrote:
I was checking ROM and RAM size in arduino_101:
CONFIG_XIP=y
CONFIG_PHYS_LOAD_ADDR=0x40030000
CONFIG_PHYS_RAM_ADDR =0xA8006400
CONFIG_RAM_SIZE=55
CONFIG_ROM_SIZE=144

Why load-address(0x40030000) is lower compare to ram-address (0xA8006400)?
PHYS_LOAD_ADDR is where the code (and rodata, etc...) goes. Quark SE
is an execute-in-place architecture, so that address is mapped
directly to the flash space on the chip, there is no step where the
code gets "copied into memory" as there is on bigger machines.

As far as why flash is mapped lower than RAM, that's just an arbitrary
choice by the hardware designers.

Andy

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