feat: integrate gdb support over serial port for bare-metal debugging.

[lunaix-os.git] / lunaix-os / debug / sdbg.c

diff --git a/lunaix-os/debug/sdbg.c b/lunaix-os/debug/sdbg.c
new file mode 100644 (file)
index 0000000..537e9cd
--- /dev/null
+++ b/lunaix-os/debug/sdbg.c
@@ -0,0 +1,83 @@
+#include <hal/acpi/acpi.h>
+#include <hal/ioapic.h>
+#include <klibc/stdio.h>
+#include <lunaix/lxconsole.h>
+#include <lunaix/peripheral/serial.h>
+#include <lunaix/syslog.h>
+#include <sdbg/gdbstub.h>
+#include <sdbg/lsdbg.h>
+#include <sdbg/protocol.h>
+
+// #define USE_LSDBG_BACKEND
+
+volatile int debug_mode = 0;
+
+void
+sdbg_loop(const isr_param* param)
+{
+    // This is importnat, because we will handle any subsequent RX/TX in a
+    // synchronized way. And we don't want these irq queue up at our APIC and
+    // confuse the CPU after ACK with APIC.
+    serial_disable_irq(SERIAL_COM1);
+    if (param->vector == 1 || param->vector == 3) {
+        goto cont;
+    }
+
+    if (!debug_mode) {
+        // Oh... C.M.C. is about to help the debugging!
+        if (serial_rx_byte(SERIAL_COM1) != '@') {
+            goto done;
+        }
+        if (serial_rx_byte(SERIAL_COM1) != 'c') {
+            goto done;
+        }
+        if (serial_rx_byte(SERIAL_COM1) != 'm') {
+            goto done;
+        }
+        if (serial_rx_byte(SERIAL_COM1) != 'c') {
+            goto done;
+        }
+        debug_mode = 1;
+    } else {
+        if (serial_rx_byte(SERIAL_COM1) != '@') {
+            goto cont;
+        }
+        if (serial_rx_byte(SERIAL_COM1) != 'y') {
+            goto cont;
+        }
+        if (serial_rx_byte(SERIAL_COM1) != 'a') {
+            goto cont;
+        }
+        if (serial_rx_byte(SERIAL_COM1) != 'y') {
+            goto cont;
+        }
+        debug_mode = 0;
+        goto done;
+    }
+
+cont:
+    kprint_dbg(" DEBUG");
+#ifdef USE_LSDBG_BACKEND
+    lunaix_sdbg_loop(param);
+#else
+    gdbstub_loop(param);
+#endif
+    console_flush();
+
+done:
+    serial_enable_irq(SERIAL_COM1);
+}
+
+extern uint8_t
+ioapic_get_irq(acpi_context* acpi_ctx, uint8_t old_irq);
+
+void
+sdbg_init()
+{
+    intr_subscribe(UART_COM1, sdbg_loop);
+    intr_subscribe(INSTR_DEBUG, sdbg_loop); // #DB
+
+    acpi_context* acpi_ctx = acpi_get_context();
+    uint8_t irq = ioapic_get_irq(acpi_ctx, COM1_IRQ);
+    ioapic_redirect(irq, UART_COM1, 0, IOAPIC_DELMOD_FIXED);
+}
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