Introduce zeromem_dczva function on AArch64 that can handle unaligned
addresses and make use of DC ZVA instruction to zero a whole block at a
time. This zeroing takes place directly in the cache to speed it up
without doing external memory access.
Remove the zeromem16 function on AArch64 and replace it with an alias to
zeromem. This zeromem16 function is now deprecated.
Remove the 16-bytes alignment constraint on __BSS_START__ in
firmware-design.md as it is now not mandatory anymore (it used to comply
with zeromem16 requirements).
Change the 16-bytes alignment constraints in SP min's linker script to a
8-bytes alignment constraint as the AArch32 zeromem implementation is now
more efficient on 8-bytes aligned addresses.
Introduce zero_normalmem and zeromem helpers in platform agnostic header
that are implemented this way:
* AArch32:
* zero_normalmem: zero using usual data access
* zeromem: alias for zero_normalmem
* AArch64:
* zero_normalmem: zero normal memory using DC ZVA instruction
(needs MMU enabled)
* zeromem: zero using usual data access
Usage guidelines: in most cases, zero_normalmem should be preferred.
There are 2 scenarios where zeromem (or memset) must be used instead:
* Code that must run with MMU disabled (which means all memory is
considered device memory for data accesses).
* Code that fills device memory with null bytes.
Optionally, the following rule can be applied if performance is
important:
* Code zeroing small areas (few bytes) that are not secrets should use
memset to take advantage of compiler optimizations.
Note: Code zeroing security-related critical information should use
zero_normalmem/zeromem instead of memset to avoid removal by
compilers' optimizations in some cases or misbehaving versions of GCC.
FixesARM-software/tf-issues#408
Change-Id: Iafd9663fc1070413c3e1904e54091cf60effaa82
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
One nasty part of ATF is some of boolean macros are always defined
as 1 or 0, and the rest of them are only defined under certain
conditions.
For the former group, "#if FOO" or "#if !FOO" must be used because
"#ifdef FOO" is always true. (Options passed by $(call add_define,)
are the cases.)
For the latter, "#ifdef FOO" or "#ifndef FOO" should be used because
checking the value of an undefined macro is strange.
Here, IMAGE_BL* is handled by make_helpers/build_macro.mk like
follows:
$(eval IMAGE := IMAGE_BL$(call uppercase,$(3)))
$(OBJ): $(2)
@echo " CC $$<"
$$(Q)$$(CC) $$(TF_CFLAGS) $$(CFLAGS) -D$(IMAGE) -c $$< -o $$@
This means, IMAGE_BL* is defined when building the corresponding
image, but *undefined* for the other images.
So, IMAGE_BL* belongs to the latter group where we should use #ifdef
or #ifndef.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
We have lots of duplicated defines (and comment blocks too).
Move them to include/plat/common/common_def.h.
While we are here, suffix the end address with _END instead of
_LIMIT. The _END is a better fit to indicate the linker-derived
real end address.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Douglas Raillard
Masahiro Yamada
Leon Chen