/* debug-stub.c: debug-mode stub * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program 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 of the License, or (at your option) any later version. */ #include <linux/string.h>#include <linux/kernel.h>#include <linux/signal.h>#include <linux/sched.h>#include <linux/init.h>#include <linux/serial_reg.h> #include <asm/system.h>#include <asm/serial-regs.h>#include <asm/timer-regs.h>#include <asm/irc-regs.h>#include <asm/gdb-stub.h>#include "gdb-io.h" /* CPU board CON5 */#define __UART0(X) (*(volatile uint8_t *)(UART0_BASE + (UART_##X))) #define LSR_WAIT_FOR0(STATE)			\do {						\} while (!(__UART0(LSR) & UART_LSR_##STATE)) #define FLOWCTL_QUERY0(LINE)	({ __UART0(MSR) & UART_MSR_##LINE; })#define FLOWCTL_CLEAR0(LINE)	do { __UART0(MCR) &= ~UART_MCR_##LINE; } while (0)#define FLOWCTL_SET0(LINE)	do { __UART0(MCR) |= UART_MCR_##LINE; } while (0) #define FLOWCTL_WAIT_FOR0(LINE)			\do {						\	gdbstub_do_rx();			\} while(!FLOWCTL_QUERY(LINE)) struct frv_debug_status __debug_status; static void __init debug_stub_init(void); /*****************************************************************************//* * debug mode handler stub * - we come here with the CPU in debug mode and with exceptions disabled * - handle debugging services for userspace */asmlinkage void debug_stub(void){	unsigned long hsr0;	int type = 0; 	static u8 inited = 0;	if (!inited) {		debug_stub_init();		type = -1;		inited = 1;	} 	hsr0 = __get_HSR(0);	if (hsr0 & HSR0_ETMD)		__set_HSR(0, hsr0 & ~HSR0_ETMD); 	/* disable single stepping */	__debug_status.dcr &= ~DCR_SE; 	/* kernel mode can propose an exception be handled in debug mode by jumping to a special	 * location */	if (__debug_frame->pc == (unsigned long) __break_hijack_kernel_event_breaks_here) {		/* replace the debug frame with the kernel frame and discard		 * the top kernel context */		*__debug_frame = *__frame;		__frame = __debug_frame->next_frame;		__debug_status.brr = (__debug_frame->tbr & TBR_TT) << 12;		__debug_status.brr |= BRR_EB;	} 	if (__debug_frame->pc == (unsigned long) __debug_bug_trap + 4) {		__debug_frame->pc = __debug_frame->lr;		type = __debug_frame->gr8;	} #ifdef CONFIG_GDBSTUB	gdbstub(type);#endif 	if (hsr0 & HSR0_ETMD)		__set_HSR(0, __get_HSR(0) | HSR0_ETMD); } /* end debug_stub() */ /*****************************************************************************//* * debug stub initialisation */static void __init debug_stub_init(void){	__set_IRR(6, 0xff000000);	/* map ERRs to NMI */	__set_IITMR(1, 0x20000000);	/* ERR0/1, UART0/1 IRQ detect levels */ 	asm volatile("	movgs	gr0,ibar0	\n"		     "	movgs	gr0,ibar1	\n"		     "	movgs	gr0,ibar2	\n"		     "	movgs	gr0,ibar3	\n"		     "	movgs	gr0,dbar0	\n"		     "	movgs	gr0,dbmr00	\n"		     "	movgs	gr0,dbmr01	\n"		     "	movgs	gr0,dbdr00	\n"		     "	movgs	gr0,dbdr01	\n"		     "	movgs	gr0,dbar1	\n"		     "	movgs	gr0,dbmr10	\n"		     "	movgs	gr0,dbmr11	\n"		     "	movgs	gr0,dbdr10	\n"		     "	movgs	gr0,dbdr11	\n"		     ); 	/* deal with debugging stub initialisation and initial pause */	if (__debug_frame->pc == (unsigned long) __debug_stub_init_break)		__debug_frame->pc = (unsigned long) start_kernel; 	/* enable the debug events we want to trap */	__debug_status.dcr = DCR_EBE; #ifdef CONFIG_GDBSTUB	gdbstub_init();#endif 	__clr_MASK_all();	__clr_MASK(15);	__clr_RC(15); } /* end debug_stub_init() */ /*****************************************************************************//* * kernel "exit" trap for gdb stub */void debug_stub_exit(int status){ #ifdef CONFIG_GDBSTUB	gdbstub_exit(status);#endif } /* end debug_stub_exit() */ /*****************************************************************************//* * send string to serial port */void debug_to_serial(const char *p, int n){	char ch; 	for (; n > 0; n--) {		ch = *p++;		FLOWCTL_SET0(DTR);		LSR_WAIT_FOR0(THRE);		// FLOWCTL_WAIT_FOR(CTS); 		if (ch == 0x0a) {			__UART0(TX) = 0x0d;			mb();			LSR_WAIT_FOR0(THRE);			// FLOWCTL_WAIT_FOR(CTS);		}		__UART0(TX) = ch;		mb(); 		FLOWCTL_CLEAR0(DTR);	} } /* end debug_to_serial() */ /*****************************************************************************//* * send string to serial port */void debug_to_serial2(const char *fmt, ...){	va_list va;	char buf[64];	int n; 	va_start(va, fmt);	n = vsprintf(buf, fmt, va);	va_end(va); 	debug_to_serial(buf, n); } /* end debug_to_serial2() */ /*****************************************************************************//* * set up the ttyS0 serial port baud rate timers */void __init console_set_baud(unsigned baud){	unsigned value, high, low;	u8 lcr; 	/* work out the divisor to give us the nearest higher baud rate */	value = __serial_clock_speed_HZ / 16 / baud; 	/* determine the baud rate range */	high = __serial_clock_speed_HZ / 16 / value;	low = __serial_clock_speed_HZ / 16 / (value + 1); 	/* pick the nearest bound */	if (low + (high - low) / 2 > baud)		value++; 	lcr = __UART0(LCR);	__UART0(LCR) |= UART_LCR_DLAB;	mb();	__UART0(DLL) = value & 0xff;	__UART0(DLM) = (value >> 8) & 0xff;	mb();	__UART0(LCR) = lcr;	mb(); } /* end console_set_baud() */ /*****************************************************************************//* * */int __init console_get_baud(void){	unsigned value;	u8 lcr; 	lcr = __UART0(LCR);	__UART0(LCR) |= UART_LCR_DLAB;	mb();	value =  __UART0(DLM) << 8;	value |= __UART0(DLL);	__UART0(LCR) = lcr;	mb(); 	return value;} /* end console_get_baud() */ /*****************************************************************************//* * display BUG() info */#ifndef CONFIG_NO_KERNEL_MSGvoid __debug_bug_printk(const char *file, unsigned line){	printk("kernel BUG at %s:%d!\n", file, line); } /* end __debug_bug_printk() */#endif