Code drop from //branches/cupcake/...@124589
diff --git a/qemu/qemu.c b/qemu/qemu.c
new file mode 100644
index 0000000..2631c58
--- /dev/null
+++ b/qemu/qemu.c
@@ -0,0 +1,312 @@
+/*
+ * 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.
+ */
+
+/* this file contains various functions used by all libhardware modules
+ * that support QEMU emulation
+ */
+#include "qemu.h"
+#define LOG_TAG "hardware-qemu"
+#include <cutils/log.h>
+#include <cutils/properties.h>
+#include <cutils/sockets.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+#define QEMU_DEBUG 0
+
+#if QEMU_DEBUG
+# define D(...) LOGD(__VA_ARGS__)
+#else
+# define D(...) ((void)0)
+#endif
+
+
+int
+qemu_check(void)
+{
+ static int in_qemu = -1;
+
+ if (__builtin_expect(in_qemu < 0,0)) {
+ char propBuf[PROPERTY_VALUE_MAX];
+ property_get("ro.kernel.qemu", propBuf, "");
+ in_qemu = (propBuf[0] == '1');
+ }
+ return in_qemu;
+}
+
+
+int
+qemu_channel_open( QemuChannel* channel,
+ const char* name,
+ int mode )
+{
+ int fd = -1;
+
+ /* initialize the channel is needed */
+ if (!channel->is_inited)
+ {
+ int done = 0;
+
+ // try to connect to qemud socket first
+ do {
+ snprintf(channel->device, sizeof channel->device,
+ "qemud_%s", name);
+
+ fd = socket_local_client( channel->device,
+ ANDROID_SOCKET_NAMESPACE_RESERVED,
+ SOCK_STREAM );
+ if (fd < 0) {
+ D("no '%s' control socket available: %s",
+ channel->device, strerror(errno));
+ break;
+ }
+ close(fd);
+ channel->is_qemud = 1;
+ done = 1;
+ } while (0);
+
+ // otherwise, look for a kernel-provided device name
+ if (!done) do {
+ char key[PROPERTY_KEY_MAX];
+ char prop[PROPERTY_VALUE_MAX];
+ int ret;
+
+ ret = snprintf(key, sizeof key, "ro.kernel.android.%s", name);
+ if (ret >= (int)sizeof key)
+ break;
+
+ if (property_get(key, prop, "") == 0) {
+ D("no kernel-provided %s device name", name);
+ break;
+ }
+
+ ret = snprintf(channel->device, sizeof channel->device,
+ "/dev/%s", prop);
+ if (ret >= (int)sizeof channel->device) {
+ D("%s device name too long: '%s'", name, prop);
+ break;
+ }
+ channel->is_tty = !memcmp("/dev/tty", channel->device, 8);
+ done = 1;
+
+ } while (0);
+
+ channel->is_available = done;
+ channel->is_inited = 1;
+ }
+
+ /* try to open the file */
+ if (!channel->is_available) {
+ fd = -1;
+ errno = ENOENT;
+ } else if (channel->is_qemud) {
+ do {
+ fd = socket_local_client( channel->device,
+ ANDROID_SOCKET_NAMESPACE_RESERVED,
+ SOCK_STREAM );
+ } while (fd < 0 && errno == EINTR);
+ } else {
+ do {
+ fd = open(channel->device, mode);
+ } while (fd < 0 && errno == EINTR);
+
+ /* disable ECHO on serial lines */
+ if (fd >= 0 && channel->is_tty) {
+ struct termios ios;
+ tcgetattr( fd, &ios );
+ ios.c_lflag = 0; /* disable ECHO, ICANON, etc... */
+ tcsetattr( fd, TCSANOW, &ios );
+ }
+ }
+ return fd;
+}
+
+
+static int
+qemu_command_vformat( char* buffer,
+ int buffer_size,
+ const char* format,
+ va_list args )
+{
+ char header[5];
+ int len;
+
+ if (buffer_size < 6)
+ return -1;
+
+ len = vsnprintf(buffer+4, buffer_size-4, format, args);
+ if (len >= buffer_size-4)
+ return -1;
+
+ snprintf(header, sizeof header, "%04x", len);
+ memcpy(buffer, header, 4);
+ return len + 4;
+}
+
+extern int
+qemu_command_format( char* buffer,
+ int buffer_size,
+ const char* format,
+ ... )
+{
+ va_list args;
+ int ret;
+
+ va_start(args, format);
+ ret = qemu_command_format(buffer, buffer_size, format, args);
+ va_end(args);
+ return ret;
+}
+
+
+static int
+qemu_control_fd(void)
+{
+ static QemuChannel channel[1];
+ int fd;
+
+ fd = qemu_channel_open( channel, "control", O_RDWR );
+ if (fd < 0) {
+ D("%s: could not open control channel: %s", __FUNCTION__,
+ strerror(errno));
+ }
+ return fd;
+}
+
+static int
+qemu_control_write( int fd, const char* cmd, int len )
+{
+ int len2;
+ do {
+ len2 = write(fd, cmd, len);
+ } while (len2 < 0 && errno == EINTR);
+ return len2;
+}
+
+static int
+qemu_control_read( int fd, char* buff, int len )
+{
+ int len2;
+ do {
+ len2 = read(fd, buff, len);
+ } while (len2 < 0 && errno == EINTR);
+ return len2;
+}
+
+static int
+qemu_control_send(const char* cmd, int len)
+{
+ int fd, len2;
+
+ if (len < 0) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ fd = qemu_control_fd();
+ if (fd < 0)
+ return -1;
+
+ len2 = qemu_control_write(fd, cmd, len);
+ close(fd);
+ if (len2 != len) {
+ D("%s: could not send everything %d < %d",
+ __FUNCTION__, len2, len);
+ return -1;
+ }
+ return 0;
+}
+
+
+int
+qemu_control_command( const char* fmt, ... )
+{
+ va_list args;
+ char command[256];
+ int len, fd;
+
+ va_start(args, fmt);
+ len = qemu_command_vformat( command, sizeof command, fmt, args );
+ va_end(args);
+
+ if (len < 0 || len >= (int)sizeof command) {
+ if (len < 0) {
+ D("%s: could not send: %s", __FUNCTION__, strerror(errno));
+ } else {
+ D("%s: too large %d > %d", __FUNCTION__, len, (int)(sizeof command));
+ }
+ errno = EINVAL;
+ return -1;
+ }
+
+ return qemu_control_send( command, len );
+}
+
+extern int qemu_control_query( const char* question, int questionlen,
+ char* answer, int answersize )
+{
+ int ret, fd, len, result = -1;
+ char header[5], *end;
+
+ if (questionlen <= 0) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ fd = qemu_control_fd();
+ if (fd < 0)
+ return -1;
+
+ ret = qemu_control_write( fd, question, questionlen );
+ if (ret != questionlen) {
+ D("%s: could not write all: %d < %d", __FUNCTION__,
+ ret, questionlen);
+ goto Exit;
+ }
+
+ /* read a 4-byte header giving the length of the following content */
+ ret = qemu_control_read( fd, header, 4 );
+ if (ret != 4) {
+ D("%s: could not read header (%d != 4)",
+ __FUNCTION__, ret);
+ goto Exit;
+ }
+
+ header[5] = 0;
+ len = strtol( header, &end, 16 );
+ if ( len < 0 || end == NULL || end != header+4 || len > answersize ) {
+ D("%s: could not parse header: '%s'",
+ __FUNCTION__, header);
+ goto Exit;
+ }
+
+ /* read the answer */
+ ret = qemu_control_read( fd, answer, len );
+ if (ret != len) {
+ D("%s: could not read all of answer %d < %d",
+ __FUNCTION__, ret, len);
+ goto Exit;
+ }
+
+ result = len;
+
+Exit:
+ close(fd);
+ return result;
+}