Commit graph

6 commits

Author SHA1 Message Date
Philipp Tomsich
b4806d6f1f 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>
2017-11-21 23:57:22 +01:00
Tom Rini
3a649407a4 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>
2017-03-18 20:28:01 -04:00
Alexander Graf
692fcdd800 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>
2016-10-08 09:33:34 -04:00
Alexander Graf
0de02de768 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>
2016-07-08 17:16:38 -04:00
Alexander Graf
e677724884 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>
2016-06-17 09:51:06 -04:00
Alexander Graf
97d44b1f5c 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>
2016-06-06 13:39:15 -04:00