Mercurial > nand-ecoscentric
diff packages/hal/cortexm/arch/current/src/mcount.S @ 3357:0e7f32e78b4d
* src/mcount.S: Add mcount functions for call-graph profiling.
* cdl/hal_cortexm.cdl: Add option to build mcount functions.
[ Bugzilla 1001954 ]
| author | jld |
|---|---|
| date | Mon, 03 Mar 2014 08:30:32 +0000 |
| parents | |
| children |
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new file mode 100644 --- /dev/null +++ b/packages/hal/cortexm/arch/current/src/mcount.S @@ -0,0 +1,138 @@ +/*========================================================================== +// +// mcount.S +// +// Cortex-M mcount implementation +// +//========================================================================== +// ####ECOSGPLCOPYRIGHTBEGIN#### +// ------------------------------------------- +// This file is part of eCos, the Embedded Configurable Operating System. +// Copyright (C) 2014 Free Software Foundation, Inc. +// +// eCos is free software; you can redistribute it and/or modify it under +// the terms of the GNU General Public License as published by the Free +// Software Foundation; either version 2 or (at your option) any later +// version. +// +// eCos is distributed in the hope that it will be useful, but WITHOUT +// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +// for more details. +// +// You should have received a copy of the GNU General Public License +// along with eCos; if not, write to the Free Software Foundation, Inc., +// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +// +// As a special exception, if other files instantiate templates or use +// macros or inline functions from this file, or you compile this file +// and link it with other works to produce a work based on this file, +// this file does not by itself cause the resulting work to be covered by +// the GNU General Public License. However the source code for this file +// must still be made available in accordance with section (3) of the GNU +// General Public License v2. +// +// This exception does not invalidate any other reasons why a work based +// on this file might be covered by the GNU General Public License. +// ------------------------------------------- +// ####ECOSGPLCOPYRIGHTEND#### +//========================================================================== +//#####DESCRIPTIONBEGIN#### +// +// Author(s): jld +// Contributor(s): +// Date: 2014-02-28 +// Description: This file provides mcount functions used for +// call-graph profiling. +// +//####DESCRIPTIONEND#### +// +//======================================================================== +*/ + +#include <pkgconf/hal_cortexm.h> + +/* +// GCC inserts mcount code at the start of every function when compiling +// with "-pg". For GCC prior to version 4.4 targeting Cortex-M, +// the following code is inserted: +// +// mov r12, lr +// bl mcount +// .word <data pointer> +// +// For GCC version 4.4 and later targeting Cortex-M, the following code is +// inserted: +// +// push { lr } +// bl __gnu_mcount_nc +// +// We provide implementations of both mcount() and __gnu_mcount_nc() to +// call the eCos __profile_mcount() function. +*/ + + .syntax unified + .globl mcount + .section .text.mcount + .thumb_func +mcount: + // resume execution beyond the data pointer on return to caller + add lr, lr, #4 + + // caller assumes r0-r3 will be preserved (non-AAPCS), we use + // r6 and must preserve lr across our __profile_mcount() call + push { r0, r1, r2, r3, r6, lr } + + // set up parameters for __profile_mcount() + sub r0, r12, #2 + bic r0, r0, #1 + bic r1, lr, #1 + + // disable interrupts + mov r2, #CYGNUM_HAL_CORTEXM_PRIORITY_MAX + mrs r6, basepri + msr basepri, r2 + + // call eCos __profile_mcount() + // r6 is preserved across the call per AAPCS + bl __profile_mcount + + // restore interrupts + msr basepri, r6 + + // restore registers and return + pop { r0, r1, r2, r3, r6, pc } + + + .globl __gnu_mcount_nc + .section .text.__gnu_mcount_nc + .thumb_func +__gnu_mcount_nc: + // caller assumes r0-r3 will be preserved (non-AAPCS), we use + // r6 and must preserve lr across our __profile_mcount() call + push { r0, r1, r2, r3, r6, lr } + + // set up parameters for __profile_mcount() + ldr r0, [ sp, #24 ] + sub r0, r0, #2 + bic r0, r0, #1 + bic r1, lr, #1 + + // disable interrupts + mov r2, #CYGNUM_HAL_CORTEXM_PRIORITY_MAX + mrs r6, basepri + msr basepri, r2 + + // call eCos __profile_mcount() + // r6 is preserved across the call per AAPCS + bl __profile_mcount + + // restore interrupts + msr basepri, r6 + + // restore registers and return + pop { r0, r1, r2, r3, r6, r12, lr } + bx r12 + +//========================================================================== +// end of mcount.S
