[linux] Add initial implementation of rom-loader

1 files changed, 89 insertions, 0 deletions

diff --git a/sw-linux/rom-loader/serial.cpp b/sw-linux/rom-loader/serial.cpp
new file mode 100644
index 0000000..7d25f02
--- /dev/null
+++ b/sw-linux/rom-loader/serial.cpp
@@ -0,0 +1,89 @@
+#include "serial.hpp"
+
+#include <ios>
+
+extern "C" {
+#include <fcntl.h>
+#include <termios.h>
+#include <unistd.h>
+}
+
+serial::serial(const std::string& port, speed_t baud)
+{
+    m_fd = open(port.c_str(), O_RDWR | O_NOCTTY | O_NDELAY);
+
+    if (m_fd < 0) {
+        throw std::ios_base::failure("Failed to open serial port " + port);
+    }
+
+    tcgetattr(m_fd, &m_settings);
+
+    // set input and output baudrate
+    cfsetispeed(&m_settings, baud);
+    cfsetospeed(&m_settings, baud);
+
+    // disable parity, 1 stop bit, clear data size
+    m_settings.c_cflag &= ~(PARENB | CSTOPB | CSIZE);
+    // set data size to 8
+    m_settings.c_cflag |= CS8;
+
+    // disable hw flow control
+    m_settings.c_cflag &= ~CRTSCTS;
+    // enable receiver and ignore modem lines
+    m_settings.c_cflag |= CREAD | CLOCAL;
+
+    // disable XON / XOFF flow control
+    m_settings.c_iflag &= ~(IXON | IXOFF | IXANY);
+    // non canonical mode
+    m_settings.c_iflag &= ~(ICANON | ECHO | ECHOE | ISIG);
+
+    // no output processing
+    m_settings.c_oflag &= ~OPOST;
+    
+    // input buffer of 8 bytes
+    m_settings.c_cc[VMIN] = 8;
+    // set indefinite timeout
+    m_settings.c_cc[VTIME] = 0;
+
+    if ((tcsetattr(m_fd, TCSANOW, &m_settings)) != 0)
+        throw std::ios_base::failure("Failed to set attributes");
+
+    // clean rx buffer
+    tcflush(m_fd, TCIFLUSH);
+}
+
+serial::~serial()
+{
+    if (m_fd > 0)
+        close(m_fd);
+}
+
+int serial::write(const std::string& data) const
+{
+    write(data.c_str(), data.length());
+}
+
+int serial::write(const char * const data, size_t len) const
+{
+    return ::write(m_fd, data, len);
+}
+
+char serial::read() const
+{
+    char ch;
+
+    if (::read(m_fd, &ch, 1) < 0)
+        throw std::ios_base::failure("Failed to read");
+
+    return ch;
+}
+
+std::string serial::read(size_t howmany) const
+{
+    char data[howmany] = {};
+
+    if (::read(m_fd, data, howmany) < 0)
+        throw std::ios_base::failure("Failed to read");
+
+    return std::string(data);
+}