From: Wolfgang Wegner <wolfgang@leila.ping.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] FPGA relocation/C environment
Date: Thu, 29 Oct 2009 16:44:55 +0100 [thread overview]
Message-ID: <20091029154455.GJ3216@leila.ping.de> (raw)
In-Reply-To: <20091029150004.GI3216@leila.ping.de>
Hi,
although I have to leave for now, just some questions to see if
there is anything I understood correctly until now...
- in the PPC startup (assembly) files, the section .got2 is explicitely
created using START_GOT etc.
- .got2 contains some vital pointers (vectors) as well as data
pointers like a pointer to .fixup and a pointer to itself (?!)
- the ppc linker automatically puts .data.rel (and other relocatable
sections?) into .fixup (which seems not the case with my m68k linker)
- the ppc startup code uses some obfuscated assembly code ;-) to
relocate both the global relocation table (.got) as well as the
sections .got2 and .fixup (.got seems to be implicitly mentioned:
"/* First our own GOT */
add r14, r14, r15
/* then the one used by the C code */
add r30, r30, r15"
but I can not see where it is actually relocated...)
Is this correct so far? I am not sure because it seems more complicated
than necessary to me (especially the algorithm to relocate .got2 and
.fixup - or is this all about the possibility to do multiple relocations?),
so maybe I still have a misunderstanding here. Furthermore, the special
handling of r14 (-ffixed-r14 in config.mk) still puzzles me.
Thank you and best regards,
Wolfgang
next prev parent reply other threads:[~2009-10-29 15:44 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-29 8:21 [U-Boot] FPGA relocation/C environment Wolfgang Wegner
2009-10-29 11:00 ` Wolfgang Denk
2009-10-29 12:04 ` Wolfgang Wegner
2009-10-29 13:08 ` Joakim Tjernlund
2009-10-29 13:41 ` Wolfgang Wegner
2009-10-29 14:22 ` Joakim Tjernlund
2009-10-29 15:00 ` Wolfgang Wegner
2009-10-29 15:44 ` Wolfgang Wegner [this message]
2009-10-29 16:39 ` Joakim Tjernlund
2009-10-30 13:11 ` Wolfgang Wegner
2009-10-30 23:16 ` Graeme Russ
2009-10-29 15:47 ` Joakim Tjernlund
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