1 files changed, 104 insertions, 0 deletions

diff --git a/include/asm-arm/kgdb.h b/include/asm-arm/kgdb.h
new file mode 100644
index 000000000000..67af4b841984
--- /dev/null
+++ b/include/asm-arm/kgdb.h
@@ -0,0 +1,104 @@
+/*
+ * ARM KGDB support
+ *
+ * Author: Deepak Saxena <dsaxena@mvista.com>
+ *
+ * Copyright (C) 2002 MontaVista Software Inc.
+ *
+ */
+
+#ifndef __ARM_KGDB_H__
+#define __ARM_KGDB_H__
+
+#include <linux/ptrace.h>
+
+/*
+ * GDB assumes that we're a user process being debugged, so
+ * it will send us an SWI command to write into memory as the
+ * debug trap. When an SWI occurs, the next instruction addr is
+ * placed into R14_svc before jumping to the vector trap.
+ * This doesn't work for kernel debugging as we are already in SVC
+ * we would loose the kernel's LR, which is a bad thing. This
+ * is  bad thing.
+ *
+ * By doing this as an undefined instruction trap, we force a mode
+ * switch from SVC to UND mode, allowing us to save full kernel state.
+ *
+ * We also define a KGDB_COMPILED_BREAK which can be used to compile
+ * in breakpoints. This is important for things like sysrq-G and for
+ * the initial breakpoint from trap_init().
+ *
+ * Note to ARM HW designers: Add real trap support like SH && PPC to
+ * make our lives much much simpler. :)
+ */
+#define BREAK_INSTR_SIZE        4
+#define GDB_BREAKINST           0xef9f0001
+#define KGDB_BREAKINST          0xe7ffdefe
+#define KGDB_COMPILED_BREAK     0xe7ffdeff
+#define CACHE_FLUSH_IS_SAFE     1
+
+#ifndef __ASSEMBLY__
+
+static inline void arch_kgdb_breakpoint(void)
+{
+        asm(".word 0xe7ffdeff");
+}
+
+extern void kgdb_handle_bus_error(void);
+extern int kgdb_fault_expected;
+
+#endif /* !__ASSEMBLY__ */
+
+/*
+ * From Kevin Hilman:
+ *
+ * gdb is expecting the following registers layout.
+ *
+ * r0-r15: 1 long word each
+ * f0-f7:  unused, 3 long words each !!
+ * fps:    unused, 1 long word
+ * cpsr:   1 long word
+ *
+ * Even though f0-f7 and fps are not used, they need to be
+ * present in the registers sent for correct processing in
+ * the host-side gdb.
+ *
+ * In particular, it is crucial that CPSR is in the right place,
+ * otherwise gdb will not be able to correctly interpret stepping over
+ * conditional branches.
+ */
+#define _GP_REGS                16
+#define _FP_REGS                8
+#define _EXTRA_REGS             2
+#define GDB_MAX_REGS            (_GP_REGS + (_FP_REGS * 3) + _EXTRA_REGS)
+
+#define KGDB_MAX_NO_CPUS        1
+#define BUFMAX                  400
+#define NUMREGBYTES             (GDB_MAX_REGS << 2)
+#define NUMCRITREGBYTES         (32 << 2)
+
+#define _R0                     0
+#define _R1                     1
+#define _R2                     2
+#define _R3                     3
+#define _R4                     4
+#define _R5                     5
+#define _R6                     6
+#define _R7                     7
+#define _R8                     8
+#define _R9                     9
+#define _R10                    10
+#define _FP                     11
+#define _IP                     12
+#define _SPT                    13
+#define _LR                     14
+#define _PC                     15
+#define _CPSR                   (GDB_MAX_REGS - 1)
+
+/*
+ * So that we can denote the end of a frame for tracing,
+ * in the simple case:
+ */
+#define CFI_END_FRAME(func)     __CFI_END_FRAME(_PC, _SPT, func)
+
+#endif /* __ASM_KGDB_H__ */