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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-08-31 14:29:34 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-08-31 18:45:19 +0900 |
| commit | fed18b3aec0f575752eeca0ca8c24d7dd16dac78 (patch) | |
| tree | 084b5e3ff0a61c7aec9c5a1f86ec709e7614a017 /include/common | |
| parent | d818a02cb489eae1f99cabf949d47e56347e4537 (diff) | |
| download | platform_external_arm-trusted-firmware-fed18b3aec0f575752eeca0ca8c24d7dd16dac78.tar.gz platform_external_arm-trusted-firmware-fed18b3aec0f575752eeca0ca8c24d7dd16dac78.tar.bz2 platform_external_arm-trusted-firmware-fed18b3aec0f575752eeca0ca8c24d7dd16dac78.zip | |
asm_macros: set the default assembly code alignment to 4 byte
Assembly routines are usually defined by using "func" and "endfunc":
func foo
...
endfunc foo
Currently, the "func" macro does not specify ".align" directive
by default. It causes unaligned instruction under some circumstances.
As far as I tested, this problem happens for GCC 5 or older. It did
not happen for GCC 6 or newer. Taking into account that GCC 4.x / 5.x
is still used, make sure that assembly code is at least 4 byte aligned.
[ How to reproduce the problem ]
For example, use GCC 5.3 downloaded from Linaro:
http://releases.linaro.org/components/toolchain/binaries/5.3-2016.05/
aarch64-linux-gnu/gcc-linaro-5.3.1-2016.05-x86_64_aarch64-linux-gnu.tar.xz
Expand mbedtls-2.4.2 to the current directory.
Try the following:
$ git log --oneline -1
77544ef Merge pull request #1071 from jeenu-arm/syntax-fix
$ aarch64-linux-gnu-gcc --version | head -1
aarch64-linux-gnu-gcc (Linaro GCC 5.3-2016.05) 5.3.1 20160412
$ make CROSS_COMPILE=aarch64-linux-gnu- PLAT=uniphier \
TRUSTED_BOARD_BOOT=1 MBEDTLS_DIR=mbedtls-2.4.2
( snip build log )
$ aarch64-linux-gnu-nm build/uniphier/release/bl1/bl1.elf | grep handler
00000000800088f4 T bl1_fwu_smc_handler
00000000800084c8 T bl1_smc_handler
000000008000a6e0 t _panic_handler
000000008000a8e0 W plat_error_handler
000000008000a8e8 W plat_panic_handler
000000008000a8d8 W plat_reset_handler
000000008000a39f T reset_handler
000000008000a367 t smc_handler
000000008000a2ef t smc_handler64
You will notice "smc_handler64", "reset_handler", etc. are not properly
aligned.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Diffstat (limited to 'include/common')
| -rw-r--r-- | include/common/asm_macros_common.S | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/include/common/asm_macros_common.S b/include/common/asm_macros_common.S index dbc9e2d30..6a02e18ee 100644 --- a/include/common/asm_macros_common.S +++ b/include/common/asm_macros_common.S @@ -12,11 +12,12 @@ * to enable elimination of unused code during linking. It also adds * basic debug information to enable call stack printing most of the * time. The optional _align parameter can be used to force a - * non-standard alignment (indicated in powers of 2). Do *not* try to - * use a raw .align directive. Since func switches to a new section, - * this would not have the desired effect. + * non-standard alignment (indicated in powers of 2). The default is + * _align=2 because both Aarch32 and Aarch64 instructions must be + * word aligned. Do *not* try to use a raw .align directive. Since func + * switches to a new section, this would not have the desired effect. */ - .macro func _name, _align=-1 + .macro func _name, _align=2 /* * Add Call Frame Information entry in the .debug_frame section for * debugger consumption. This enables callstack printing in debuggers. @@ -36,9 +37,7 @@ * .debug_frame */ .cfi_startproc - .if (\_align) != -1 - .align \_align - .endif + .align \_align \_name: .endm |