u-boot.git/arch/mips/cpu/u-boot.lds, branch master

mips: Update linker scripts to ensure appended device tree is aligned

2026-01-20T18:07:16+00:00

With commit 0535e46d55d7 ("scripts/dtc: Update to upstream version
v1.7.2-35-g52f07dcca47c") it is now a fatal error to U-Boot if our
device tree is not 8-byte aligned. In commit 85f586035d75 ("ARM: OMAP2+:
Pad SPL binary to 8-byte alignment before DTB") Beleswar Padhi explains
that we must have ALIGN(x) statements inside of a section to ensure that
padding is included and not simply that the linker address counter is
incremented. To that end, this patch:
- Aligns the final section before _end (for U-Boot) or _image_binary_end
  (for xPL phases) by 8-bytes by adding '. = ALIGN(8);' to the final
  section before the symbol. For SPL we need this in two places to cover
  all build configurations.
- Remove now-spurious  '. = ALIGN(x);' statements that were intended to
  provide the above alignments.
- Ensure that we do have alignment by adding an ASSERT so that when not
  aligned we fail to link (and explain why).

Reviewed-by: Daniel Schwierzeck 
Signed-off-by: Tom Rini

MIPS: Assure end of U-Boot is at 8-byte aligned offset

2025-11-28T16:20:22+00:00

Make sure the end of U-Boot is at 8-byte aligned offset, not 4-byte
aligned offset. This allows safely appending DT at the end of U-Boot
with the guarantee that the DT will be at 8-byte aligned offset. This
8-byte alignment is now checked by newer libfdt 1.7.2 .

Signed-off-by: Marek Vasut

linker_lists: Rename sections to remove . prefix

2022-06-23T16:58:18+00:00

Rename the sections used to implement linker lists so they begin with
'__u_boot_list' rather than '.u_boot_list'. The double underscore at the
start is still distinct from the single underscore used by the symbol
names.

Having a '.' in the section names conflicts with clang's ASAN
instrumentation which tries to add redzones between the linker list
elements, causing expected accesses to fail. However, clang doesn't try
to add redzones to user sections, which are names with all alphanumeric
and underscore characters.

Signed-off-by: Andrew Scull 
Reviewed-by: Simon Glass

MIPS: optimize and fix ELF sections

2019-01-16T12:56:43+00:00

Discard ABI related sections which are not required for debugging.
Rearrange debug sections similar to Linux. Remove the remaining
explicitely specified sections in the unused part because those
sections are not created anymore or because the linker puts them
by default at the end of the ELF binary.

Signed-off-by: Daniel Schwierzeck 
Tested-by: Ezequiel Garcia

MIPS: make size of relocation table fixed but configurable

2018-11-02T21:39:07+00:00

Currently the size of the relocation table will be shrunk
to the actual size needed. Although this gives a maximal
space saving, it messes up the _end symbol. This breaks
features like appended DTBs because the _end symbol doesn't
point to the real end of the U-Boot binary.

Remove the size shrinking and make the size of the relocation
table fixed but configurable. This follows the Linux approach
and the user can adjust the size to his needs.

Also rename the relocation table section from .rel to .data.reloc
to follow the Linux approach and to avoid ambiguities with the
.rel.* sections added by the linker.

Reported-by: Lars Povlsen 
Signed-off-by: Daniel Schwierzeck

SPDX: Convert all of our single license tags to Linux Kernel style

2018-05-07T13:34:12+00:00

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini

MIPS: Drop unused PTR_COUNT_SHIFT from u-boot.lds

2017-11-28T20:59:30+00:00

The u-boot.lds linker script for MIPS defines a PTR_COUNT_SHIFT macro to
2 or 3 for 32 bit or 64 bit builds respectively. This macro is never
actually used though, so remove the dead code.

Signed-off-by: Paul Burton 
Cc: Daniel Schwierzeck

MIPS: Stop building position independent code

2017-07-25T18:44:00+00:00

U-Boot has up until now built with -fpic for the MIPS architecture,
producing position independent code which uses indirection through a
global offset table, making relocation fairly straightforward as it
simply involves patching up GOT entries.

Using -fpic does however have some downsides. The biggest of these is
that generated code is bloated in various ways. For example, function
calls are indirected through the GOT & the t9 register:

  8f998064   lw     t9,-32668(gp)
  0320f809   jalr   t9

Without -fpic the call is simply:

  0f803f01   jal    be00fc04 

This is more compact & faster (due to the lack of the load & the
dependency the jump has on its result). It is also easier to read &
debug because the disassembly shows what function is being called,
rather than just an offset from gp which would then have to be looked up
in the ELF to discover the target function.

Another disadvantage of -fpic is that each function begins with a
sequence to calculate the value of the gp register, for example:

  3c1c0004   lui    gp,0x4
  279c3384   addiu  gp,gp,13188
  0399e021   addu   gp,gp,t9

Without using -fpic this sequence no longer appears at the start of each
function, reducing code size considerably.

This patch switches U-Boot from building with -fpic to building with
-fno-pic, in order to gain the benefits described above. The cost of
this is an extra step during the build process to extract relocation
data from the ELF & write it into a new .rel section in a compact
format, plus the added complexity of dealing with multiple types of
relocation rather than the single type that applied to the GOT. The
benefit is smaller, cleaner, more debuggable code. The relocate_code()
function is reimplemented in C to handle the new relocation scheme,
which also makes it easier to read & debug.

Taking maltael_defconfig as an example the size of u-boot.bin built
using the Codescape MIPS 2016.05-06 toolchain (gcc 4.9.2, binutils
2.24.90) shrinks from 254KiB to 224KiB.

Signed-off-by: Paul Burton 
Cc: Daniel Schwierzeck 
Cc: u-boot@lists.denx.de
Reviewed-by: Daniel Schwierzeck 
Tested-by: Daniel Schwierzeck

MIPS: Fix cache maintenance in relocate_code & simplify

2016-09-21T14:25:43+00:00

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

MIPS: add .padding section to linker script

2014-11-01T17:18:05+00:00

Commit 79fd7e649e287228a1445820a72f7dd33baedb96

    MIPS: always keep all sections in u-boot ELF binary.

    Always keep all sections in u-boot ELF binary. Move all unneeded
    sections after _end to avoid allocating space in the final binary.
    Also remove .deadcode section which is now obsolete.

removed section .deadcode because the original symptoms were not
visible anymore. Unfortuneatly the binutils bug still exists.

The size of .rel.dyn section is often bigger than needed for all
entries. But objcopy only allocates space as much as required for all
reloc entries. Thus there is a gap between the last entry and
__rel_dyn_end in u-boot.bin. If u-boot is booted from RAM (e.g. in
SPL scenarios) that area could contain garbage data which could lead
to CPU exceptions during relocation.

Signed-off-by: Gabor Juhos 
Signed-off-by: Daniel Schwierzeck