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Diffstat (limited to 'bsps/i386/pc386/console/i386-stub-glue.c')
-rw-r--r--bsps/i386/pc386/console/i386-stub-glue.c273
1 files changed, 273 insertions, 0 deletions
diff --git a/bsps/i386/pc386/console/i386-stub-glue.c b/bsps/i386/pc386/console/i386-stub-glue.c
new file mode 100644
index 0000000000..868ae6384d
--- /dev/null
+++ b/bsps/i386/pc386/console/i386-stub-glue.c
@@ -0,0 +1,273 @@
+/*
+ * Copyright (c) 2016.
+ * Chris Johns <chrisj@rtems.org>
+ *
+ * This software is Copyright (C) 1998 by T.sqware - all rights limited
+ * It is provided in to the public domain "as is", can be freely modified
+ * as far as this copyight notice is kept unchanged, but does not imply
+ * an endorsement by T.sqware of the product in which it is included.
+ */
+
+#include <bsp.h>
+#include <bsp/irq-generic.h>
+#include <libchip/serial.h>
+
+#include "../../../shared/dev/serial/legacy-console.h"
+
+int putDebugChar(int ch); /* write a single character */
+int getDebugChar(void); /* read and return a single char */
+
+/* Check is any characters received are a ^C */
+int i386_gdb_uart_ctrl_c_check(void);
+
+/* Raw interrupt handler. */
+void i386_gdb_uart_isr(void);
+
+/* assign an exception handler */
+void exceptionHandler(int, void (*handler)(void));
+
+/* User supplied remote debug option. */
+extern int remote_debug;
+
+/* Current uart and port used by the gdb stub */
+static int uart_current;
+static int uart_vector;
+static console_tbl* port_current;
+
+/*
+ * Interrupt service routine for all, it does it check whether ^C is received
+ * if yes it will flip TF bit before returning.
+ *
+ * Note: it should be installed as raw interrupt handler.
+ *
+ * Warning: I do not like the use of the global data, I am not
+ * sure if this is SMP safe.
+ */
+int i386_gdb_uart_isr_regsav[4] RTEMS_UNUSED;
+__asm__ (".p2align 4");
+__asm__ (".text");
+__asm__ (".globl i386_gdb_uart_isr");
+__asm__ ("i386_gdb_uart_isr:");
+__asm__ (" pusha"); /* Push all */
+__asm__ (" call i386_gdb_uart_ctrl_c_check"); /* Look for ^C */
+__asm__ (" movl %eax, i386_gdb_uart_isr_regsav"); /* Save eax */
+__asm__ (" popa"); /* Pop all */
+__asm__ (" xchgl %eax, i386_gdb_uart_isr_regsav"); /* Exchange eax */
+__asm__ (" cmpl $0, %eax"); /* 1 == ^C */
+__asm__ (" je i386_gdb_uart_isr_1"); /* branch if 0 */
+__asm__ (" movl %ebx, i386_gdb_uart_isr_regsav + 4"); /* Save ebx */
+__asm__ (" movl %edx, i386_gdb_uart_isr_regsav + 8"); /* Save edx */
+__asm__ (" popl %ebx"); /* Pop eip */
+__asm__ (" popl %edx"); /* Pop cs */
+__asm__ (" popl %eax"); /* Pop flags */
+__asm__ (" orl $0x100, %eax"); /* Modify it */
+__asm__ (" pushl %eax"); /* Push it back */
+__asm__ (" pushl %edx"); /* Push cs */
+__asm__ (" pushl %ebx"); /* Push eip */
+__asm__ (" movl i386_gdb_uart_isr_regsav + 4, %ebx"); /* Restore ebx */
+__asm__ (" movl i386_gdb_uart_isr_regsav + 8, %edx"); /* Restore edx */
+__asm__ ("i386_gdb_uart_isr_1:");
+__asm__ (" movl i386_gdb_uart_isr_regsav, %eax"); /* Restore eax */
+__asm__ (" iret"); /* Done */
+
+static int gdb_hello_index;
+static const char *const gdb_hello = "+";
+
+static inline uint8_t BSP_i8259a_irq_in_service_reg(uint32_t ioport)
+{
+ uint8_t isr;
+ outport_byte(ioport, PIC_OCW3_SEL | PIC_OCW3_RR | PIC_OCW3_RIS);
+ inport_byte(ioport, isr);
+ outport_byte(ioport, PIC_OCW3_SEL | PIC_OCW3_RR);
+ return isr;
+}
+
+static inline void BSP_irq_ack_at_i8259a(const int irqLine)
+{
+ uint8_t slave_isr = 0;
+ if (irqLine >= 8) {
+ outport_byte(PIC_SLAVE_COMMAND_IO_PORT, PIC_EOI);
+ slave_isr = BSP_i8259a_irq_in_service_reg(PIC_SLAVE_COMMAND_IO_PORT);
+ }
+
+ /*
+ * Only issue the EOI to the master if there are no more interrupts in
+ * service for the slave. i8259a data sheet page 18, The Special Fully Nested
+ * Mode, b.
+ */
+ if (slave_isr == 0)
+ outport_byte(PIC_MASTER_COMMAND_IO_PORT, PIC_EOI);
+}
+
+int i386_gdb_uart_ctrl_c_check(void)
+{
+ BSP_irq_ack_at_i8259a(uart_vector);
+ if (port_current) {
+ int c = 0;
+ while (c >= 0) {
+ c = port_current->pDeviceFns->deviceRead(uart_current);
+ if (c == 3) {
+ gdb_hello_index = 0;
+ return 1;
+ } else if (gdb_hello[gdb_hello_index] == (char) c) {
+ ++gdb_hello_index;
+ if (gdb_hello[gdb_hello_index] == '\0') {
+ gdb_hello_index = 0;
+ return 1;
+ }
+ } else {
+ gdb_hello_index = 0;
+ }
+ }
+ }
+ return 0;
+}
+
+static void
+nop(const rtems_raw_irq_connect_data* notused)
+{
+}
+
+static int
+isOn(const rtems_raw_irq_connect_data* notused)
+{
+ return 1;
+}
+
+int i386_stub_glue_uart(void)
+{
+ if (port_current == NULL)
+ return -1;
+ return uart_current;
+}
+
+/*
+ * Initialize glue code linking i386-stub with the rest of
+ * the system
+ */
+void
+i386_stub_glue_init(int uart)
+{
+ rtems_device_minor_number minor = (rtems_device_minor_number) uart;
+
+ port_current = console_find_console_entry(NULL, 0, &minor);
+
+ if (port_current == NULL) {
+ printk("GDB: invalid minor number for UART\n");
+ return;
+ }
+
+ uart_current = uart;
+
+ /* Intialise the UART, assuming polled drivers */
+ port_current->pDeviceFns->deviceInitialize(uart);
+}
+
+static void BSP_uart_on(const rtems_raw_irq_connect_data* used)
+{
+ bsp_interrupt_vector_enable(used->idtIndex - BSP_IRQ_VECTOR_BASE);
+}
+
+static void BSP_uart_off(const rtems_raw_irq_connect_data* used)
+{
+ bsp_interrupt_vector_disable(used->idtIndex - BSP_IRQ_VECTOR_BASE);
+}
+
+/*
+ * In order to have a possibility to break into
+ * running program, one has to call this function
+ */
+void i386_stub_glue_init_breakin(void)
+{
+ rtems_raw_irq_connect_data uart_raw_irq_data;
+
+ if (port_current == NULL) {
+ printk("GDB: no port initialised\n");
+ return;
+ }
+
+ if ((port_current->ulIntVector == 0) || (port_current->ulIntVector > 16)) {
+ printk("GDB: no UART interrupt support\n");
+ }
+ else {
+ uart_vector = port_current->ulIntVector;
+ uart_raw_irq_data.idtIndex = port_current->ulIntVector + BSP_IRQ_VECTOR_BASE;
+
+ if (!i386_get_current_idt_entry(&uart_raw_irq_data)) {
+ printk("GBD: cannot get idt entry\n");
+ rtems_fatal_error_occurred(1);
+ }
+
+ if (!i386_delete_idt_entry(&uart_raw_irq_data)) {
+ printk("GDB: cannot delete idt entry\n");
+ rtems_fatal_error_occurred(1);
+ }
+
+ uart_raw_irq_data.on = BSP_uart_on;
+ uart_raw_irq_data.off = BSP_uart_off;
+
+ /* Install ISR */
+ uart_raw_irq_data.idtIndex = port_current->ulIntVector + BSP_IRQ_VECTOR_BASE;
+ uart_raw_irq_data.hdl = i386_gdb_uart_isr;
+
+ if (!i386_set_idt_entry (&uart_raw_irq_data)) {
+ printk("GDB: raw exception handler connection failed\n");
+ rtems_fatal_error_occurred(1);
+ }
+
+ /* Enable interrupts, this is a bit of a hack because we
+ * have to know the device but there is no other call. */
+ (*port_current->setRegister)(port_current->ulCtrlPort1, 1, 0x01);
+ }
+}
+
+int
+putDebugChar(int ch)
+{
+ if (port_current != NULL) {
+ port_current->pDeviceFns->deviceWritePolled(uart_current, ch);
+ }
+ return 1;
+}
+
+int getDebugChar(void)
+{
+ int c = -1;
+
+ if (port_current != NULL) {
+ while (c < 0)
+ c = port_current->pDeviceFns->deviceRead(uart_current);
+ }
+
+ return c;
+}
+
+void exceptionHandler(int vector, void (*handler)(void))
+{
+ rtems_raw_irq_connect_data excep_raw_irq_data;
+
+ excep_raw_irq_data.idtIndex = vector;
+
+ if(!i386_get_current_idt_entry(&excep_raw_irq_data))
+ {
+ printk("GDB: cannot get idt entry\n");
+ rtems_fatal_error_occurred(1);
+ }
+
+ if(!i386_delete_idt_entry(&excep_raw_irq_data))
+ {
+ printk("GDB: cannot delete idt entry\n");
+ rtems_fatal_error_occurred(1);
+ }
+
+ excep_raw_irq_data.on = nop;
+ excep_raw_irq_data.off = nop;
+ excep_raw_irq_data.isOn = isOn;
+ excep_raw_irq_data.hdl = handler;
+
+ if (!i386_set_idt_entry (&excep_raw_irq_data)) {
+ printk("GDB: raw exception handler connection failed\n");
+ rtems_fatal_error_occurred(1);
+ }
+ return;
+}
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