1. 18 Jan, 2018 1 commit
  2. 31 Aug, 2017 1 commit
    • Masahiro Yamada's avatar
      asm_macros: set the default assembly code alignment to 4 byte · fed18b3a
      Masahiro Yamada authored
      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
        77544efb
      
       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: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      fed18b3a
  3. 15 Aug, 2017 1 commit
    • Julius Werner's avatar
      Add new alignment parameter to func assembler macro · 64726e6d
      Julius Werner authored
      
      
      Assembler programmers are used to being able to define functions with a
      specific aligment with a pattern like this:
      
          .align X
        myfunction:
      
      However, this pattern is subtly broken when instead of a direct label
      like 'myfunction:', you use the 'func myfunction' macro that's standard
      in Trusted Firmware. Since the func macro declares a new section for the
      function, the .align directive written above it actually applies to the
      *previous* section in the assembly file, and the function it was
      supposed to apply to is linked with default alignment.
      
      An extreme case can be seen in Rockchip's plat_helpers.S which contains
      this code:
      
        [...]
        endfunc plat_crash_console_putc
      
        .align 16
        func platform_cpu_warmboot
        [...]
      
      This assembles into the following plat_helpers.o:
      
        Sections:
        Idx Name                             Size  [...]  Algn
         9 .text.plat_crash_console_putc 00010000  [...]  2**16
        10 .text.platform_cpu_warmboot   00000080  [...]  2**3
      
      As can be seen, the *previous* function actually got the alignment
      constraint, and it is also 64KB big even though it contains only two
      instructions, because the .align directive at the end of its section
      forces the assembler to insert a giant sled of NOPs. The function we
      actually wanted to align has the default constraint. This code only
      works at all because the linker just happens to put the two functions
      right behind each other when linking the final image, and since the end
      of plat_crash_console_putc is aligned the start of platform_cpu_warmboot
      will also be. But it still wastes almost 64KB of image space
      unnecessarily, and it will break under certain circumstances (e.g. if
      the plat_crash_console_putc function becomes unused and its section gets
      garbage-collected out).
      
      There's no real way to fix this with the existing func macro. Code like
      
       func myfunc
       .align X
      
      happens to do the right thing, but is still not really correct code
      (because the function label is inserted before the .align directive, so
      the assembler is technically allowed to insert padding at the beginning
      of the function which would then get executed as instructions if the
      function was called). Therefore, this patch adds a new parameter with a
      default value to the func macro that allows overriding its alignment.
      
      Also fix up all existing instances of this dangerous antipattern.
      
      Change-Id: I5696a07e2fde896f21e0e83644c95b7b6ac79a10
      Signed-off-by: default avatarJulius Werner <jwerner@chromium.org>
      64726e6d
  4. 03 May, 2017 1 commit
  5. 21 Nov, 2016 1 commit
    • Douglas Raillard's avatar
      Add CFI debug frame information for ASM functions · b91d935f
      Douglas Raillard authored
      
      
      This allows the debugger to print the callstack when there is an
      assembly function in the callstack.
      
      It will work as long as the CFA pointer (frame pointer) location is not
      modified (i.e. x29 is not touched in AArch64 state). It is the case in
      almost all assembly functions, so this patch improves the average
      debugging experience. Call stacks from the debugger should still be
      interpreted with care. In more complex functions, one could use .cfi*
      directives to inform the debugger about the new location of the CFA
      pointer.
      
      Change-Id: I9dabfbc033b45e8528e67f4823c17de7bf02fa24
      Signed-off-by: default avatarDouglas Raillard <douglas.raillard@arm.com>
      b91d935f
  6. 10 Aug, 2016 1 commit
    • Soby Mathew's avatar
      AArch32: Add assembly helpers · f24307de
      Soby Mathew authored
      This patch adds various assembly helpers for AArch32 like :
      
      * cache management : Functions to flush, invalidate and clean
      cache by MVA. Also helpers to do cache operations by set-way
      are also added.
      
      * stack management: Macros to declare stack and get the current
      stack corresponding to current CPU.
      
      * Misc: Macros to access co processor registers in AArch32,
      macros to define functions in assembly, assert macros, generic
      `do_panic()` implementation and function to zero block of memory.
      
      Change-Id: I7b78ca3f922c0eda39beb9786b7150e9193425be
      f24307de
  7. 19 Jul, 2016 1 commit
    • Soby Mathew's avatar
      Rearrange assembly helper macros · 738b1fd7
      Soby Mathew authored
      This patch moves assembler macros which are not architecture specific
      to a new file `asm_macros_common.S` and moves the `el3_common_macros.S`
      into `aarch64` specific folder.
      
      Change-Id: I444a1ee3346597bf26a8b827480cd9640b38c826
      738b1fd7