openrisc: fix relocation code

The relocation code can now relocate from anywhere to
the RAM.

The old code assumed that the binary was copied to the RAM
by some PBL and then it just relocated the .text section
from the loaded address to the linked address.

Now, it first checks if vectors are somewhere else than the
linked address. If yes, there are copied to address 0 (or
to the exception vector base address if register EVBAR is
present).

Then, the .text section is relocated from its current location
to the RAM.

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
This commit is contained in:
Franck Jullien 2014-05-21 22:43:50 +02:00 committed by Tom Rini
parent c346cf1350
commit 9cd73bf859

View file

@ -1,6 +1,7 @@
/*
* (C) Copyright 2011, Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
* (C) Copyright 2011, Julius Baxter <julius@opencores.org>
* (C) Copyright 2014, Franck Jullien <franck.jullien@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
@ -40,9 +41,48 @@ __reset:
l.ori r3,r0,SPR_SR_SM
l.mtspr r0,r3,SPR_SR
l.jal _cur
l.nop
_cur:
l.ori r8, r9, 0 /* Get _cur current address */
l.movhi r3, hi(_cur)
l.ori r3, r3, lo(_cur)
l.sfeq r8, r3 /* If we are running at the linked address */
l.bf _no_vector_reloc /* there is not need for relocation */
l.sub r8, r8, r3
l.mfspr r4, r0, SPR_CPUCFGR
l.andi r4, r4, SPR_CPUCFGR_EVBARP /* Exception Vector Base Address Register present ? */
l.sfnei r4,0
l.bnf _reloc_vectors
l.movhi r5, 0 /* Destination */
l.mfspr r4, r0, SPR_EVBAR
l.add r5, r5, r4
_reloc_vectors:
/* Relocate vectors*/
l.movhi r5, 0 /* Destination */
l.movhi r6, hi(__start) /* Length */
l.ori r6, r6, lo(__start)
l.ori r3, r8, 0
.L_relocvectors:
l.lwz r7, 0(r3)
l.sw 0(r5), r7
l.addi r5, r5, 4
l.sfeq r5, r6
l.bnf .L_relocvectors
l.addi r3, r3, 4
_no_vector_reloc:
/* Relocate u-boot */
l.movhi r3,hi(__start) /* source start address */
l.movhi r3,hi(__start) /* source start offset */
l.ori r3,r3,lo(__start)
l.add r3,r8,r3
l.movhi r4,hi(_stext) /* dest start address */
l.ori r4,r4,lo(_stext)
l.movhi r5,hi(__end) /* dest end address */
@ -56,19 +96,6 @@ __reset:
l.bf .L_reloc
l.addi r4,r4,4 /* delay slot */
#ifdef CONFIG_SYS_RELOCATE_VECTORS
/* Relocate vectors from 0xf0000000 to 0x00000000 */
l.movhi r4, 0xf000 /* source */
l.movhi r5, 0 /* destination */
l.addi r6, r5, CONFIG_SYS_VECTORS_LEN /* length */
.L_relocvectors:
l.lwz r7, 0(r4)
l.sw 0(r5), r7
l.addi r5, r5, 4
l.sfeq r5,r6
l.bnf .L_relocvectors
l.addi r4,r4, 4
#endif
l.movhi r4,hi(_start)
l.ori r4,r4,lo(_start)
l.jr r4