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-rw-r--r--grub-core/term/ns8250.c318
1 files changed, 318 insertions, 0 deletions
diff --git a/grub-core/term/ns8250.c b/grub-core/term/ns8250.c
new file mode 100644
index 0000000..39809d0
--- /dev/null
+++ b/grub-core/term/ns8250.c
@@ -0,0 +1,318 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2000,2001,2002,2003,2004,2005,2007,2008,2009,2010 Free Software Foundation, Inc.
+ *
+ * GRUB 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/serial.h>
+#include <grub/ns8250.h>
+#include <grub/types.h>
+#include <grub/dl.h>
+#include <grub/misc.h>
+#include <grub/cpu/io.h>
+#include <grub/mm.h>
+#include <grub/time.h>
+#include <grub/i18n.h>
+
+#ifdef GRUB_MACHINE_PCBIOS
+#include <grub/machine/memory.h>
+static const unsigned short *serial_hw_io_addr = (const unsigned short *) GRUB_MEMORY_MACHINE_BIOS_DATA_AREA_ADDR;
+#define GRUB_SERIAL_PORT_NUM 4
+#else
+#include <grub/machine/serial.h>
+static const grub_port_t serial_hw_io_addr[] = GRUB_MACHINE_SERIAL_PORTS;
+#define GRUB_SERIAL_PORT_NUM (ARRAY_SIZE(serial_hw_io_addr))
+#endif
+
+static int dead_ports = 0;
+
+#ifdef GRUB_MACHINE_MIPS_LOONGSON
+#define DEFAULT_BASE_CLOCK (2 * 115200)
+#else
+#define DEFAULT_BASE_CLOCK 115200
+#endif
+
+
+/* Convert speed to divisor. */
+static unsigned short
+serial_get_divisor (const struct grub_serial_port *port __attribute__ ((unused)),
+ const struct grub_serial_config *config)
+{
+ grub_uint32_t base_clock;
+ grub_uint32_t divisor;
+ grub_uint32_t actual_speed, error;
+
+ base_clock = config->base_clock ? (config->base_clock >> 4) : DEFAULT_BASE_CLOCK;
+
+ divisor = (base_clock + (config->speed / 2)) / config->speed;
+ if (config->speed == 0)
+ return 0;
+ if (divisor > 0xffff || divisor == 0)
+ return 0;
+ actual_speed = base_clock / divisor;
+ error = actual_speed > config->speed ? (actual_speed - config->speed)
+ : (config->speed - actual_speed);
+ if (error > (config->speed / 30 + 1))
+ return 0;
+ return divisor;
+}
+
+static void
+do_real_config (struct grub_serial_port *port)
+{
+ int divisor;
+ unsigned char status = 0;
+ grub_uint64_t endtime;
+
+ const unsigned char parities[] = {
+ [GRUB_SERIAL_PARITY_NONE] = UART_NO_PARITY,
+ [GRUB_SERIAL_PARITY_ODD] = UART_ODD_PARITY,
+ [GRUB_SERIAL_PARITY_EVEN] = UART_EVEN_PARITY
+ };
+ const unsigned char stop_bits[] = {
+ [GRUB_SERIAL_STOP_BITS_1] = UART_1_STOP_BIT,
+ [GRUB_SERIAL_STOP_BITS_2] = UART_2_STOP_BITS,
+ };
+
+ if (port->configured)
+ return;
+
+ port->broken = 0;
+
+ divisor = serial_get_divisor (port, &port->config);
+
+ /* Turn off the interrupt. */
+ grub_outb (0, port->port + UART_IER);
+
+ /* Set DLAB. */
+ grub_outb (UART_DLAB, port->port + UART_LCR);
+
+ /* Set the baud rate. */
+ grub_outb (divisor & 0xFF, port->port + UART_DLL);
+ grub_outb (divisor >> 8, port->port + UART_DLH);
+
+ /* Set the line status. */
+ status |= (parities[port->config.parity]
+ | (port->config.word_len - 5)
+ | stop_bits[port->config.stop_bits]);
+ grub_outb (status, port->port + UART_LCR);
+
+ if (port->config.rtscts)
+ {
+ /* Enable the FIFO. */
+ grub_outb (UART_ENABLE_FIFO_TRIGGER1, port->port + UART_FCR);
+
+ /* Turn on DTR and RTS. */
+ grub_outb (UART_ENABLE_DTRRTS, port->port + UART_MCR);
+ }
+ else
+ {
+ /* Enable the FIFO. */
+ grub_outb (UART_ENABLE_FIFO_TRIGGER14, port->port + UART_FCR);
+
+ /* Turn on DTR, RTS, and OUT2. */
+ grub_outb (UART_ENABLE_DTRRTS | UART_ENABLE_OUT2, port->port + UART_MCR);
+ }
+
+ /* Drain the input buffer. */
+ endtime = grub_get_time_ms () + 1000;
+ while (grub_inb (port->port + UART_LSR) & UART_DATA_READY)
+ {
+ grub_inb (port->port + UART_RX);
+ if (grub_get_time_ms () > endtime)
+ {
+ port->broken = 1;
+ break;
+ }
+ }
+
+ port->configured = 1;
+}
+
+/* Fetch a key. */
+static int
+serial_hw_fetch (struct grub_serial_port *port)
+{
+ do_real_config (port);
+ if (grub_inb (port->port + UART_LSR) & UART_DATA_READY)
+ return grub_inb (port->port + UART_RX);
+
+ return -1;
+}
+
+/* Put a character. */
+static void
+serial_hw_put (struct grub_serial_port *port, const int c)
+{
+ grub_uint64_t endtime;
+
+ do_real_config (port);
+
+ if (port->broken > 5)
+ endtime = grub_get_time_ms ();
+ else if (port->broken > 1)
+ endtime = grub_get_time_ms () + 50;
+ else
+ endtime = grub_get_time_ms () + 200;
+ /* Wait until the transmitter holding register is empty. */
+ while ((grub_inb (port->port + UART_LSR) & UART_EMPTY_TRANSMITTER) == 0)
+ {
+ if (grub_get_time_ms () > endtime)
+ {
+ port->broken++;
+ /* There is something wrong. But what can I do? */
+ return;
+ }
+ }
+
+ if (port->broken)
+ port->broken--;
+
+ grub_outb (c, port->port + UART_TX);
+}
+
+/* Initialize a serial device. PORT is the port number for a serial device.
+ SPEED is a DTE-DTE speed which must be one of these: 2400, 4800, 9600,
+ 19200, 38400, 57600 and 115200. WORD_LEN is the word length to be used
+ for the device. Likewise, PARITY is the type of the parity and
+ STOP_BIT_LEN is the length of the stop bit. The possible values for
+ WORD_LEN, PARITY and STOP_BIT_LEN are defined in the header file as
+ macros. */
+static grub_err_t
+serial_hw_configure (struct grub_serial_port *port,
+ struct grub_serial_config *config)
+{
+ unsigned short divisor;
+
+ divisor = serial_get_divisor (port, config);
+ if (divisor == 0)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT,
+ N_("unsupported serial port speed"));
+
+ if (config->parity != GRUB_SERIAL_PARITY_NONE
+ && config->parity != GRUB_SERIAL_PARITY_ODD
+ && config->parity != GRUB_SERIAL_PARITY_EVEN)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT,
+ N_("unsupported serial port parity"));
+
+ if (config->stop_bits != GRUB_SERIAL_STOP_BITS_1
+ && config->stop_bits != GRUB_SERIAL_STOP_BITS_2)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT,
+ N_("unsupported serial port stop bits number"));
+
+ if (config->word_len < 5 || config->word_len > 8)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT,
+ N_("unsupported serial port word length"));
+
+ port->config = *config;
+ port->configured = 0;
+
+ /* FIXME: should check if the serial terminal was found. */
+
+ return GRUB_ERR_NONE;
+}
+
+struct grub_serial_driver grub_ns8250_driver =
+ {
+ .configure = serial_hw_configure,
+ .fetch = serial_hw_fetch,
+ .put = serial_hw_put
+ };
+
+static char com_names[GRUB_SERIAL_PORT_NUM][20];
+static struct grub_serial_port com_ports[GRUB_SERIAL_PORT_NUM];
+
+void
+grub_ns8250_init (void)
+{
+ unsigned i;
+ for (i = 0; i < GRUB_SERIAL_PORT_NUM; i++)
+ if (serial_hw_io_addr[i])
+ {
+ grub_err_t err;
+
+ grub_outb (0x5a, serial_hw_io_addr[i] + UART_SR);
+ if (grub_inb (serial_hw_io_addr[i] + UART_SR) != 0x5a)
+ {
+ dead_ports |= (1 << i);
+ continue;
+ }
+ grub_outb (0xa5, serial_hw_io_addr[i] + UART_SR);
+ if (grub_inb (serial_hw_io_addr[i] + UART_SR) != 0xa5)
+ {
+ dead_ports |= (1 << i);
+ continue;
+ }
+
+ grub_snprintf (com_names[i], sizeof (com_names[i]), "com%d", i);
+ com_ports[i].name = com_names[i];
+ com_ports[i].driver = &grub_ns8250_driver;
+ com_ports[i].port = serial_hw_io_addr[i];
+ err = grub_serial_config_defaults (&com_ports[i]);
+ if (err)
+ grub_print_error ();
+
+ grub_serial_register (&com_ports[i]);
+ }
+}
+
+/* Return the port number for the UNITth serial device. */
+grub_port_t
+grub_ns8250_hw_get_port (const unsigned int unit)
+{
+ if (unit < GRUB_SERIAL_PORT_NUM
+ && !(dead_ports & (1 << unit)))
+ return serial_hw_io_addr[unit];
+ else
+ return 0;
+}
+
+char *
+grub_serial_ns8250_add_port (grub_port_t port)
+{
+ struct grub_serial_port *p;
+ unsigned i;
+ for (i = 0; i < GRUB_SERIAL_PORT_NUM; i++)
+ if (com_ports[i].port == port)
+ {
+ if (dead_ports & (1 << i))
+ return NULL;
+ return com_names[i];
+ }
+
+ grub_outb (0x5a, port + UART_SR);
+ if (grub_inb (port + UART_SR) != 0x5a)
+ return NULL;
+
+ grub_outb (0xa5, port + UART_SR);
+ if (grub_inb (port + UART_SR) != 0xa5)
+ return NULL;
+
+ p = grub_malloc (sizeof (*p));
+ if (!p)
+ return NULL;
+ p->name = grub_xasprintf ("port%lx", (unsigned long) port);
+ if (!p->name)
+ {
+ grub_free (p);
+ return NULL;
+ }
+ p->driver = &grub_ns8250_driver;
+ grub_serial_config_defaults (p);
+ p->port = port;
+ grub_serial_register (p);
+
+ return p->name;
+}
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