Index: head/sys/gdb/gdb_main.c
===================================================================
--- head/sys/gdb/gdb_main.c
+++ head/sys/gdb/gdb_main.c
@@ -769,6 +769,10 @@
 				do_qXfer();
 			} else if (gdb_rx_equal("Search:memory:")) {
 				gdb_do_mem_search();
+#ifdef __powerpc__
+			} else if (gdb_rx_equal("Offsets")) {
+				gdb_cpu_do_offsets();
+#endif
 			} else if (!gdb_cpu_query())
 				gdb_tx_empty();
 			break;
Index: head/sys/powerpc/include/gdb_machdep.h
===================================================================
--- head/sys/powerpc/include/gdb_machdep.h
+++ head/sys/powerpc/include/gdb_machdep.h
@@ -131,5 +131,6 @@
 void *gdb_cpu_getreg(int, size_t *);
 void gdb_cpu_setreg(int, void *);
 int gdb_cpu_signal(int, int);
+void gdb_cpu_do_offsets(void);
 
 #endif /* !_MACHINE_GDB_MACHDEP_H_ */
Index: head/sys/powerpc/powerpc/gdb_machdep.c
===================================================================
--- head/sys/powerpc/powerpc/gdb_machdep.c
+++ head/sys/powerpc/powerpc/gdb_machdep.c
@@ -48,6 +48,8 @@
 #include <gdb/gdb.h>
 #include <gdb/gdb_int.h>
 
+extern vm_offset_t __startkernel;
+
 void *
 gdb_cpu_getreg(int regnum, size_t *regsz)
 {
@@ -100,4 +102,29 @@
 		return (vector);
 	else
 		return (SIGEMT);
+}
+
+void
+gdb_cpu_do_offsets(void)
+{
+	/*
+	 * On PowerPC, .text starts at KERNBASE + SIZEOF_HEADERS and
+	 * text segment at KERNBASE - SIZEOF_HEADERS.
+	 * On PowerPC64, .text starts at KERNBASE and text segment at
+	 * KERNBASE - 0x100.
+	 * In both cases, the text segment offset is aligned to 64KB.
+	 *
+	 * The __startkernel variable holds the relocated KERNBASE offset.
+	 * Thus, as long as SIZEOF_HEADERS doesn't get bigger than 0x100
+	 * (which would lead to other issues), aligning __startkernel to
+	 * 64KB gives the text segment offset.
+	 *
+	 * TODO: Add DataSeg to response. On PowerPC64 all sections reside
+	 * in a single LOAD segment, but on PowerPC modifiable data reside
+	 * in a separate segment, that GDB should also relocate.
+	 */
+	gdb_tx_begin(0);
+	gdb_tx_str("TextSeg=");
+	gdb_tx_varhex(__startkernel & ~0xffff);
+	gdb_tx_end();
 }