[U-Boot-Users] Dynamic location of the environment sector

[Angelos Manousarides]

Angelos Manousarides wrote:
> env_offset is defined at common/environment.c, and this is the defined 
> used by other boards as well.
> BUT:
> 
> $ arm-linux-objdump -d common/environment.o
> 
> common/environment.o:     file format elf32-littlearm
> 
> Disassembly of section .text:
> 
> 00000000 <env_size>:
>         0:       00 80 00 00                                         ....
> 
> 00000004 <environment>:
>         4:       85 6f 43 92 62 6f 6f 74 64 65 6c 61 79 3d 35 00 
> .oC.bootdelay=5.
>        14:       62 61 75 64 72 61 74 65 3d 31 31 35 32 30 30 00 
> baudrate=115200.
>          ...
> 

Well, I decided to change the linker script to :

           cpu/pxa/start.o       (.text)
           . = 16 * 1024 - 4;
           common/environment.o  (.text)
           *(.text)

This way the environment will be alligned at the right address and I 
don't have to change the u-boot code.

What is the story of the env_size variable? The tools tin tools/env/* do 
not use this variable, the environment size is retrieved from the 
configuration files.


The only reference I found was in tools/envcrc.c:

#ifdef  ENV_IS_EMBEDDED
extern unsigned int env_size;
extern unsigned char environment;
#endif  /* ENV_IS_EMBEDDED */

These declarations though are not used anywhere on the code that follows!

In the actual u-boot code (not the tools) there is no usage. Is it some 
kind of a legacy mechanism, leftover from older versions of u-boot?

--
Angelos Manousaridis