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

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 <trini@konsulko.com>

arm: provide a PCS-compliant setjmp implementation

The previous setjmp-implementation (as a static inline function that
contained an 'asm volatile' sequence) was extremely fragile: (some
versions of) GCC optimised the set of registers. One critical example
was the removal of 'r9' from the clobber list, if -ffixed-reg9 was
supplied.

To increase robustness and ensure PCS-compliant behaviour, the setjmp
and longjmp implementation are now in assembly and closely match what
one would expect to find in a libc implementation.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Andy Yan <andy.yan@rock-chips.com>

arm: Migrate SYS_THUMB_BUILD to Kconfig, introduce SPL_SYS_THUMB_BUILD

Today, we have cases where we wish to build all of U-Boot in Thumb2 mode for
various reasons. We also have cases where we only build SPL in Thumb2 mode due
to size constraints and wish to build the rest of the system in ARM mode. So
in this migration we introduce a new symbol as well, SPL_SYS_THUMB_BUILD to
control if we build everything or just SPL (or in theory, just U-Boot) in
Thumb2 mode.

Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

arm: Add return value argument to longjmp

The normal longjmp command allows for a caller to pass the return value
of the setjmp() invocation. This patch adds that semantic to the arm
implementation of it and adjusts the efi_loader call respectively.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

arm: Fix setjmp (again)

Commit e677724 (arm: Fix setjmp) added code to fix compilation of the setjmp
code path with thumv1. Unfortunately it missed a constraint that the adr
instruction can only refer to 4 byte aligned offsets.

So this patch adds the required alignment hooks to make compilation
work again even when setjmp doesn't happen to be 4 byte aligned.

Signed-off-by: Alexander Graf <agraf@suse.de>
Tested-by: Tom Rini <trini@konsulko.com>

arm: Fix setjmp

The setjmp/longjmp implementation did not work on thumb1 implementations
because it used instruction encodings that don't exist on thumb1 yet.

This patch limits itself to thumb1 instruction set for 32bit arm and
removes a superfluous printf along the way.

Signed-off-by: Alexander Graf <agraf@suse.de>

arm: Introduce setjmp/longjmp

To quit an EFI application we will need logic to jump to the caller
of a function without returning from the function we called into,
so we need setjmp/longjmp functionality.

This patch introduces a trivial implementation of these that I
verified works on armv7, thumb2 and aarch64.

Signed-off-by: Alexander Graf <agraf@suse.de>

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

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 <trini@konsulko.com>

arm: provide a PCS-compliant setjmp implementation

The previous setjmp-implementation (as a static inline function that
contained an 'asm volatile' sequence) was extremely fragile: (some
versions of) GCC optimised the set of registers. One critical example
was the removal of 'r9' from the clobber list, if -ffixed-reg9 was
supplied.

To increase robustness and ensure PCS-compliant behaviour, the setjmp
and longjmp implementation are now in assembly and closely match what
one would expect to find in a libc implementation.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Andy Yan <andy.yan@rock-chips.com>

arm: Migrate SYS_THUMB_BUILD to Kconfig, introduce SPL_SYS_THUMB_BUILD

Today, we have cases where we wish to build all of U-Boot in Thumb2 mode for
various reasons. We also have cases where we only build SPL in Thumb2 mode due
to size constraints and wish to build the rest of the system in ARM mode. So
in this migration we introduce a new symbol as well, SPL_SYS_THUMB_BUILD to
control if we build everything or just SPL (or in theory, just U-Boot) in
Thumb2 mode.

Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

arm: Add return value argument to longjmp

The normal longjmp command allows for a caller to pass the return value
of the setjmp() invocation. This patch adds that semantic to the arm
implementation of it and adjusts the efi_loader call respectively.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

arm: Fix setjmp (again)

Commit e677724 (arm: Fix setjmp) added code to fix compilation of the setjmp
code path with thumv1. Unfortunately it missed a constraint that the adr
instruction can only refer to 4 byte aligned offsets.

So this patch adds the required alignment hooks to make compilation
work again even when setjmp doesn't happen to be 4 byte aligned.

Signed-off-by: Alexander Graf <agraf@suse.de>
Tested-by: Tom Rini <trini@konsulko.com>

arm: Fix setjmp

The setjmp/longjmp implementation did not work on thumb1 implementations
because it used instruction encodings that don't exist on thumb1 yet.

This patch limits itself to thumb1 instruction set for 32bit arm and
removes a superfluous printf along the way.

Signed-off-by: Alexander Graf <agraf@suse.de>

arm: Introduce setjmp/longjmp

To quit an EFI application we will need logic to jump to the caller
of a function without returning from the function we called into,
so we need setjmp/longjmp functionality.

This patch introduces a trivial implementation of these that I
verified works on armv7, thumb2 and aarch64.

Signed-off-by: Alexander Graf <agraf@suse.de>