diff options
Diffstat (limited to 'arch/frv/kernel/debug-stub.c')
| -rw-r--r-- | arch/frv/kernel/debug-stub.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/arch/frv/kernel/debug-stub.c b/arch/frv/kernel/debug-stub.c new file mode 100644 index 000000000000..4761cc4b4a90 --- /dev/null +++ b/arch/frv/kernel/debug-stub.c @@ -0,0 +1,259 @@ +/* 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)) + +static void __init debug_stub_init(void); + +extern asmlinkage void __break_hijack_kernel_event(void); +extern asmlinkage void __break_hijack_kernel_event_breaks_here(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_regs->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_regs->brr = (__debug_frame->tbr & TBR_TT) << 12; + __debug_regs->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_regs->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 |