doc: delete long-obsolete README.ARM-memory-map

As far back as 2011, "_armboot_start" was being described as "no
longer defined":

 commit 297f18ac0f
 Author: Greg Ungerer <greg.ungerer@opengear.com>
 Date:   Fri Sep 9 22:23:34 2011 +1000

   CM4000: fix broken flash base for OpenGear boards

   Use _bss_start_ofs as the size of the boot loader code+data that we want
   to protect in the flash. This replaces use of the no longer defined
   _armboot_start.
This commit is contained in:
Robert P. J. Day 2019-04-18 08:00:48 -04:00 committed by Tom Rini
parent 71d8e1b829
commit 9ad996adcc

View File

@ -1,17 +0,0 @@
Subject: Re: [PATCH][CFT] bring ARM memory layout in line with the documented behaviour
From: "Anders Larsen" <alarsen@rea.de>
Date: Thu, 18 Sep 2003 14:15:21 +0200
To: Wolfgang Denk <wd@denx.de>
...
>I still see references to _armboot_start, _armboot_end_data, and
>_armboot_end - which role do these play now? Can we get rid of them?
>
>How are they (should they be) set in your memory map above?
_armboot_start contains the value of CONFIG_SYS_TEXT_BASE (0xA07E0000); it seems
CONFIG_SYS_TEXT_BASE and _armboot_start are both used for the same purpose in
different parts of the (ARM) code.
Furthermore, the startup code (cpu/<arm>/start.S) internally uses
another variable (_TEXT_BASE) with the same content as _armboot_start.
I agree that this mess should be cleaned up.