u-boot/arch/mips/cpu/u-boot.lds
Paul Burton d263cda5ae MIPS: Fix cache maintenance in relocate_code & simplify
The relocate_code function was handling cache maintenance incorrectly.
It copied U-Boot to its new location, flushed the caches & then
proceeded to apply relocations & jump to the new code without flushing
the caches again. This is problematic as the instruction cache could
potentially have already fetched instructions that hadn't had relocs
applied.

Rework this to perform the flush_cache call using the code in the
original copy of U-Boot, after having applied relocations to the new
copy of U-Boot. The new U-Boot can then be jumped to safely once that
cache flush has been performed.

As part of this, since the old U-Boot is used up until after that cache
flush, complexity around loading values from the GOT using a jump & link
instruction & loads from a table is removed. Instead we can simply load
the needed values with PTR_LA fromt the original GOT.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
2016-09-21 16:25:43 +02:00

130 lines
1.7 KiB
Text

/*
* (C) Copyright 2003
* Wolfgang Denk Engineering, <wd@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#if defined(CONFIG_64BIT)
#define PTR_COUNT_SHIFT 3
#else
#define PTR_COUNT_SHIFT 2
#endif
OUTPUT_ARCH(mips)
ENTRY(_start)
SECTIONS
{
. = 0x00000000;
. = ALIGN(4);
.text : {
__text_start = .;
*(.text*)
__text_end = .;
}
. = ALIGN(4);
.rodata : {
*(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*)))
}
. = ALIGN(4);
.data : {
*(.data*)
}
. = .;
_gp = ALIGN(16) + 0x7ff0;
.got : {
*(.got)
}
num_got_entries = SIZEOF(.got) >> PTR_COUNT_SHIFT;
. = ALIGN(4);
.sdata : {
*(.sdata*)
}
. = ALIGN(4);
.u_boot_list : {
KEEP(*(SORT(.u_boot_list*)));
}
. = ALIGN(4);
__image_copy_end = .;
__init_end = .;
.rel.dyn : {
__rel_dyn_start = .;
*(.rel.dyn)
__rel_dyn_end = .;
}
.padding : {
/*
* Workaround for a binutils feature (or bug?).
*
* The GNU ld from binutils puts the dynamic relocation
* entries into the .rel.dyn section. Sometimes it
* allocates more dynamic relocation entries than it needs
* and the unused slots are set to R_MIPS_NONE entries.
*
* However the size of the .rel.dyn section in the ELF
* section header does not cover the unused entries, so
* objcopy removes those during stripping.
*
* Create a small section here to avoid that.
*/
LONG(0xFFFFFFFF)
}
_end = .;
.bss __rel_dyn_start (OVERLAY) : {
__bss_start = .;
*(.sbss.*)
*(.bss.*)
*(COMMON)
. = ALIGN(4);
__bss_end = .;
}
.dynsym _end : {
*(.dynsym)
}
.dynbss : {
*(.dynbss)
}
.dynstr : {
*(.dynstr)
}
.dynamic : {
*(.dynamic)
}
.plt : {
*(.plt)
}
.interp : {
*(.interp)
}
.gnu : {
*(.gnu*)
}
.MIPS.stubs : {
*(.MIPS.stubs)
}
.hash : {
*(.hash)
}
}