platform_hardware_libhardwa.../qemu_tracing/qemu_tracing.c
2009-03-03 19:32:14 -08:00

86 lines
2.2 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
// This is the pathname to the sysfs file that enables and disables
// tracing on the qemu emulator.
#define SYS_QEMU_TRACE_STATE "/sys/qemu_trace/state"
// This is the pathname to the sysfs file that adds new (address, symbol)
// pairs to the trace.
#define SYS_QEMU_TRACE_SYMBOL "/sys/qemu_trace/symbol"
// The maximum length of a symbol name
#define MAX_SYMBOL_NAME_LENGTH (4 * 1024)
// Allow space in the buffer for the address plus whitespace.
#define MAX_BUF_SIZE (MAX_SYMBOL_NAME_LENGTH + 20)
// return 0 on success, or an error if the qemu driver cannot be opened
int qemu_start_tracing()
{
int fd = open(SYS_QEMU_TRACE_STATE, O_WRONLY);
if (fd < 0)
return fd;
write(fd, "1\n", 2);
close(fd);
return 0;
}
int qemu_stop_tracing()
{
int fd = open(SYS_QEMU_TRACE_STATE, O_WRONLY);
if (fd < 0)
return fd;
write(fd, "0\n", 2);
close(fd);
return 0;
}
int qemu_add_mapping(unsigned int addr, const char *name)
{
char buf[MAX_BUF_SIZE];
if (strlen(name) > MAX_SYMBOL_NAME_LENGTH)
return EINVAL;
int fd = open(SYS_QEMU_TRACE_SYMBOL, O_WRONLY);
if (fd < 0)
return fd;
sprintf(buf, "%x %s\n", addr, name);
write(fd, buf, strlen(buf));
close(fd);
return 0;
}
int qemu_remove_mapping(unsigned int addr)
{
char buf[MAX_BUF_SIZE];
int fd = open(SYS_QEMU_TRACE_SYMBOL, O_WRONLY);
if (fd < 0)
return fd;
sprintf(buf, "%x\n", addr);
write(fd, buf, strlen(buf));
close(fd);
return 0;
}