From fba09d4c08df02bf54d969502252eddb930a6d5f Mon Sep 17 00:00:00 2001
From: Oleksandr Tymoshenko <gonzo@FreeBSD.org>
Date: Thu, 15 Mar 2012 05:29:51 +0000
Subject: [PATCH] Fill out fake preload structure to let userland tools like
 pmc(3) know about kernel module base address and actual size

---
 sys/conf/Makefile.mips  |  2 +-
 sys/mips/mips/machdep.c | 50 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/sys/conf/Makefile.mips b/sys/conf/Makefile.mips
index c50f9c251a8..69eea9eaff8 100644
--- a/sys/conf/Makefile.mips
+++ b/sys/conf/Makefile.mips
@@ -44,7 +44,7 @@ MKMODULESENV+=	MACHINE=${MACHINE} MACHINE_ARCH=${MACHINE_ARCH}
 # We default to the MIPS32 ISA, if none specified in the
 # kernel configuration file.
 ARCH_FLAGS?=-march=mips32
-EXTRA_FLAGS=-fno-pic -mno-abicalls -G0
+EXTRA_FLAGS=-fno-pic -mno-abicalls -G0 -DKERNLOADADDR=${KERNLOADADDR}
 
 HACK_EXTRA_FLAGS=-shared
 
diff --git a/sys/mips/mips/machdep.c b/sys/mips/mips/machdep.c
index 8a9fabe3801..21b85c571d9 100644
--- a/sys/mips/mips/machdep.c
+++ b/sys/mips/mips/machdep.c
@@ -380,6 +380,56 @@ mips_vector_init(void)
 void
 mips_postboot_fixup(void)
 {
+	static char fake_preload[256];
+	caddr_t preload_ptr = (caddr_t)&fake_preload[0];
+	size_t size = 0;
+
+	/*
+	 * Provide kernel module file information
+	 */
+	*(uint32_t*)(preload_ptr + size) = MODINFO_NAME;
+	size += sizeof(uint32_t);
+	*(uint32_t*)(preload_ptr + size) = strlen("kernel") + 1;
+	size += sizeof(uint32_t);
+	strcpy((char*)(preload_ptr + size), "kernel");
+	size += strlen("kernel") + 1;
+	size = roundup(size, sizeof(u_long));
+
+	*(uint32_t*)(preload_ptr + size) = MODINFO_TYPE;
+	size += sizeof(uint32_t);
+	*(uint32_t*)(preload_ptr + size) = strlen("elf kernel") + 1;
+	size += sizeof(uint32_t);
+	strcpy((char*)(preload_ptr + size), "elf kernel");
+	size += strlen("elf kernel") + 1;
+	size = roundup(size, sizeof(u_long));
+
+	*(uint32_t*)(preload_ptr + size) = MODINFO_ADDR;
+	size += sizeof(uint32_t);
+	*(uint32_t*)(preload_ptr + size) = sizeof(vm_offset_t);
+	size += sizeof(uint32_t);
+	*(vm_offset_t*)(preload_ptr + size) = KERNLOADADDR;
+	size += sizeof(vm_offset_t);
+	size = roundup(size, sizeof(u_long));
+
+	*(uint32_t*)(preload_ptr + size) = MODINFO_SIZE;
+	size += sizeof(uint32_t);
+	*(uint32_t*)(preload_ptr + size) = sizeof(size_t);
+	size += sizeof(uint32_t);
+	*(vm_offset_t*)(preload_ptr + size) = (size_t)&end - KERNLOADADDR;
+	size = roundup(size, sizeof(u_long));
+	size += sizeof(size_t);
+
+	/* End marker */
+	*(uint32_t*)(preload_ptr + size) = 0;
+	size += sizeof(uint32_t);
+	*(uint32_t*)(preload_ptr + size) = 0;
+	size += sizeof(uint32_t);
+
+	KASSERT((size < sizeof(fake_preload)),
+		("fake preload size is more thenallocated"));
+
+	preload_metadata = (void *)fake_preload;
+
 #ifdef DDB
 	Elf_Size *trampoline_data = (Elf_Size*)kernel_kseg0_end;
 	Elf_Size symtabsize = 0;