/* * Bedbug Functions specific to the MPC860 chip */ #include #include #include #include #include #include #include #if (CONFIG_COMMANDS & CFG_CMD_BEDBUG) && defined(CONFIG_8xx) #define MAX_BREAK_POINTS 2 extern CPU_DEBUG_CTX bug_ctx; void bedbug860_init __P((void)); void bedbug860_do_break __P((cmd_tbl_t*,int,int,char*[])); void bedbug860_break_isr __P((struct pt_regs*)); int bedbug860_find_empty __P((void)); int bedbug860_set __P((int,unsigned long)); int bedbug860_clear __P((int)); /* ====================================================================== * Initialize the global bug_ctx structure for the MPC860. Clear all * of the breakpoints. * ====================================================================== */ void bedbug860_init( void ) { int i; /* -------------------------------------------------- */ bug_ctx.hw_debug_enabled = 0; bug_ctx.stopped = 0; bug_ctx.current_bp = 0; bug_ctx.regs = NULL; bug_ctx.do_break = bedbug860_do_break; bug_ctx.break_isr = bedbug860_break_isr; bug_ctx.find_empty = bedbug860_find_empty; bug_ctx.set = bedbug860_set; bug_ctx.clear = bedbug860_clear; for( i = 1; i <= MAX_BREAK_POINTS; ++i ) (*bug_ctx.clear)( i ); puts ("BEDBUG:ready\n"); return; } /* bedbug_init_breakpoints */ /* ====================================================================== * Set/clear/show one of the hardware breakpoints for the 860. The "off" * string will disable a specific breakpoint. The "show" string will * display the current breakpoints. Otherwise an address will set a * breakpoint at that address. Setting a breakpoint uses the CPU-specific * set routine which will assign a breakpoint number. * ====================================================================== */ void bedbug860_do_break (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) { long addr = 0; /* Address to break at */ int which_bp; /* Breakpoint number */ /* -------------------------------------------------- */ if (argc < 2) { printf ("Usage:\n%s\n", cmdtp->usage); return; } /* Turn off a breakpoint */ if( strcmp( argv[ 1 ], "off" ) == 0 ) { if( bug_ctx.hw_debug_enabled == 0 ) { printf( "No breakpoints enabled\n" ); return; } which_bp = simple_strtoul( argv[ 2 ], NULL, 10 ); if( bug_ctx.clear ) (*bug_ctx.clear)( which_bp ); printf( "Breakpoint %d removed\n", which_bp ); return; } /* Show a list of breakpoints */ if( strcmp( argv[ 1 ], "show" ) == 0 ) { for( which_bp = 1; which_bp <= MAX_BREAK_POINTS; ++which_bp ) { switch( which_bp ) { case 1: addr = GET_CMPA(); break; case 2: addr = GET_CMPB(); break; case 3: addr = GET_CMPC(); break; case 4: addr = GET_CMPD(); break; } printf( "Breakpoint [%d]: ", which_bp ); if( addr == 0 ) printf( "NOT SET\n" ); else disppc( (unsigned char *)addr, 0, 1, bedbug_puts, F_RADHEX ); } return; } /* Set a breakpoint at the address */ if( !isdigit( argv[ 1 ][ 0 ])) { printf ("Usage:\n%s\n", cmdtp->usage); return; } addr = simple_strtoul( argv[ 1 ], NULL, 16 ) & 0xfffffffc; if(( bug_ctx.set ) && ( which_bp = (*bug_ctx.set)( 0, addr )) > 0 ) { printf( "Breakpoint [%d]: ", which_bp ); disppc( (unsigned char *)addr, 0, 1, bedbug_puts, F_RADHEX ); } return; } /* bedbug860_do_break */ /* ====================================================================== * Handle a breakpoint. First determine which breakpoint was hit by * looking at the DeBug Status Register (DBSR), clear the breakpoint * and enter a mini main loop. Stay in the loop until the stopped flag * in the debug context is cleared. * ====================================================================== */ void bedbug860_break_isr( struct pt_regs *regs ) { unsigned long addr; /* Address stopped at */ unsigned long cause; /* Address stopped at */ /* -------------------------------------------------- */ cause = GET_ICR(); if( !(cause & 0x00000004)) { printf( "Not an instruction breakpoint (ICR 0x%08lx)\n", cause ); return; } addr = regs->nip; if( addr == GET_CMPA() ) { bug_ctx.current_bp = 1; } else if( addr == GET_CMPB() ) { bug_ctx.current_bp = 2; } else if( addr == GET_CMPC() ) { bug_ctx.current_bp = 3; } else if( addr == GET_CMPD() ) { bug_ctx.current_bp = 4; } bedbug_main_loop( addr, regs ); return; } /* bedbug860_break_isr */ /* ====================================================================== * Look through all of the hardware breakpoints available to see if one * is unused. * ====================================================================== */ int bedbug860_find_empty( void ) { /* -------------------------------------------------- */ if( GET_CMPA() == 0 ) return 1; if( GET_CMPB() == 0 ) return 2; if( GET_CMPC() == 0 ) return 3; if( GET_CMPD() == 0 ) return 4; return 0; } /* bedbug860_find_empty */ /* ====================================================================== * Set a breakpoint. If 'which_bp' is zero then find an unused breakpoint * number, otherwise reassign the given breakpoint. If hardware debugging * is not enabled, then turn it on via the MSR and DBCR0. Set the break * address in the appropriate IACx register and enable proper address * beakpoint in DBCR0. * ====================================================================== */ int bedbug860_set( int which_bp, unsigned long addr ) { /* -------------------------------------------------- */ /* Only look if which_bp == 0, else use which_bp */ if(( bug_ctx.find_empty ) && ( !which_bp ) && ( which_bp = (*bug_ctx.find_empty)()) == 0 ) { printf( "All breakpoints in use\n" ); return 0; } if( which_bp < 1 || which_bp > MAX_BREAK_POINTS ) { printf( "Invalid break point # %d\n", which_bp ); return 0; } if( ! bug_ctx.hw_debug_enabled ) { bug_ctx.hw_debug_enabled = 1; SET_DER( GET_DER() | 0x00000004 ); } switch( which_bp ) { case 1: SET_CMPA( addr ); SET_ICTRL( GET_ICTRL() | 0x80080800 ); /* CTA=Equal,IW0=Match A,SIW0EN */ break; case 2: SET_CMPB( addr ); SET_ICTRL( GET_ICTRL() | 0x10020400 ); /* CTB=Equal,IW1=Match B,SIW1EN */ break; case 3: SET_CMPC( addr ); SET_ICTRL( GET_ICTRL() | 0x02008200 ); /* CTC=Equal,IW2=Match C,SIW2EN */ break; case 4: SET_CMPD( addr ); SET_ICTRL( GET_ICTRL() | 0x00404100 ); /* CTD=Equal,IW3=Match D,SIW3EN */ break; } return which_bp; } /* bedbug860_set */ /* ====================================================================== * Disable a specific breakoint by setting the appropriate IACx register * to zero and claring the instruction address breakpoint in DBCR0. * ====================================================================== */ int bedbug860_clear( int which_bp ) { /* -------------------------------------------------- */ if( which_bp < 1 || which_bp > MAX_BREAK_POINTS ) { printf( "Invalid break point # (%d)\n", which_bp ); return -1; } switch( which_bp ) { case 1: SET_CMPA( 0 ); SET_ICTRL( GET_ICTRL() & ~0x80080800 ); /* CTA=Equal,IW0=Match A,SIW0EN */ break; case 2: SET_CMPB( 0 ); SET_ICTRL( GET_ICTRL() & ~0x10020400 ); /* CTB=Equal,IW1=Match B,SIW1EN */ break; case 3: SET_CMPC( 0 ); SET_ICTRL( GET_ICTRL() & ~0x02008200 ); /* CTC=Equal,IW2=Match C,SIW2EN */ break; case 4: SET_CMPD( 0 ); SET_ICTRL( GET_ICTRL() & ~0x00404100 ); /* CTD=Equal,IW3=Match D,SIW3EN */ break; } return 0; } /* bedbug860_clear */ /* ====================================================================== */ #endif