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/* 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
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