/* 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_MSG void __debug_bug_printk(const char *file, unsigned line) { printk("kernel BUG at %s:%d!\n", file, line); } /* end __debug_bug_printk() */ #endif