/*
 * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Distributed under the terms of the MIT License.
 */


#include <asm_defs.h>
#include <commpage_defs.h>

#include "asm_offsets.h"
#include "syscall_numbers.h"


/*!     \fn void x86_signal_frame_function_beos(signal_frame_data* frameData)
        \brief Wrapper function for BeOS-style signal handler functions.
        \param frameData The signal frame data.
*/
FUNCTION(x86_signal_frame_function_beos):
        // set up a stack frame
        push    %ebp
        mov             %esp, %ebp

        // Move our parameter to %esi, so we can conveniently work with it. Note
        // that we're free to use non-scratch registers without saving them, since
        // we don't have any caller to save them for. The caller will restore the
        // interrupted environment anyway.
        mov             8(%ebp), %esi

        // push the parameters for the handler function

        // make space for the vregs parameter
        lea             -VREGS_sizeof(%esp), %esp
        mov             %esp, %edi

        // copy the vregs via memcpy()
        pushl   $VREGS_sizeof
        lea             SIGNAL_FRAME_DATA_context + UCONTEXT_T_uc_mcontext(%esi), %eax
        push    %eax
        push    %edi
        movl    SIGNAL_FRAME_DATA_commpage_address(%esi), %eax
        addl    4 * COMMPAGE_ENTRY_X86_MEMCPY(%eax), %eax
        call    *%eax
        addl    $12, %esp

        // the vregs are on the stack -- push user data and signal number
        movl    SIGNAL_FRAME_DATA_user_data(%esi), %eax
        push    %eax
        movl    SIGNAL_FRAME_DATA_info+SIGINFO_T_si_signo(%esi), %eax
        push    %eax

        // call the signal handler
        movl    SIGNAL_FRAME_DATA_handler(%esi), %eax
        call    *%eax
        addl    $8, %esp        // pop only signal number and user data arguments

        // copy the vregs back to the frameData structure
        pushl   $VREGS_sizeof
        push    %edi
        lea             SIGNAL_FRAME_DATA_context + UCONTEXT_T_uc_mcontext(%esi), %eax
        push    %eax
        movl    SIGNAL_FRAME_DATA_commpage_address(%esi), %eax
        addl    4 * COMMPAGE_ENTRY_X86_MEMCPY(%eax), %eax
        call    *%eax
        addl    $12 + VREGS_sizeof, %esp

        // call the _kern_restore_signal_frame() syscall -- does not return (here)
        pushl   %esi
        pushl   $0      // dummy return value
        movl    $SYSCALL_RESTORE_SIGNAL_FRAME, %eax
        int             $99

        // never gets here
FUNCTION_END(x86_signal_frame_function_beos)