the "load" command and the .bss section

[Mike Frysinger]

On Sunday 27 April 2008, Daniel Jacobowitz wrote:
> On Sun, Apr 27, 2008 at 05:09:31AM -0400, Mike Frysinger wrote:
> > i was doing a new board port using jtag and so was leveraging the "load"
> > command to setup the initial ELF in the relevant memory regions.  things
> > kept crashing on me and then i realized that the loading process wasnt
> > actually zeroing out the bss.  is there a reason for this ?  i googled
> > and flipped through the manual, but the details on what exactly the
> > "load" command is supposed to do is a bit on sketchy side.  from what i
> > can tell from the gdb source code and the actual output from running the
> > command, it walks the section headers (rather than the program headers ?)
> > and loads up everything that is in the file.  since the bss section
> > doesnt actually exist in the file and is only allocated, that is why it
> > gets skipped ?
>
> Load puts things at their LMA rather than their VMA.  So it assumes
> that whatever sets up load -> virtual also handles bss; it's more like
> flash programming than like the Linux kernel's loader.  Heck,
> sometimes it is flash programming...

ah, now that i know the intentions, may i suggest the following to the 
documentation.
-mike

2008-04-27  Mike Frysinger  <vapier@gentoo.org>

	* gdb.texinfo (Commands for Managing Targets): Clarify load command
	wrt load/virtual addresses and handling of allocated sections.
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