Add the loader side of support for preloading ELF relocatable object

format modules, which are currently only used on the amd64 platform.
This initial implementation just parses enough of the module to
allow it to extract dependencies and load all the bits into the
right place in memory, so the kernel must still do the full relocation
and linking. The details of the loaded sections are passed to the
kernel by supplying a copy of the ELF section header table as module
metadata with the MODINFOMD_SHDR tag.

3 files changed, 20 insertions, 0 deletions

diff --git a/sys/boot/i386/libi386/elf32_freebsd.c b/sys/boot/i386/libi386/elf32_freebsd.c
index a508201..5d85927 100644
--- a/sys/boot/i386/libi386/elf32_freebsd.c
+++ b/sys/boot/i386/libi386/elf32_freebsd.c
@@ -40,8 +40,10 @@ __FBSDID("$FreeBSD$");
 #include "btxv86.h"
 
 static int	elf32_exec(struct preloaded_file *amp);
+static int	elf32_obj_exec(struct preloaded_file *amp);
 
 struct file_format i386_elf = { elf32_loadfile, elf32_exec };
+struct file_format i386_elf_obj = { elf32_obj_loadfile, elf32_obj_exec };
 
 /*
  * There is an a.out kernel and one or more a.out modules loaded.  
@@ -74,3 +76,9 @@ elf32_exec(struct preloaded_file *fp)
 
     panic("exec returned");
 }
+
+static int
+elf32_obj_exec(struct preloaded_file *fp)
+{
+	return (EFTYPE);
+}
diff --git a/sys/boot/i386/libi386/elf64_freebsd.c b/sys/boot/i386/libi386/elf64_freebsd.c
index 229c259..1a5b0b2 100644
--- a/sys/boot/i386/libi386/elf64_freebsd.c
+++ b/sys/boot/i386/libi386/elf64_freebsd.c
@@ -41,8 +41,10 @@ __FBSDID("$FreeBSD$");
 #include "btxv86.h"
 
 static int	elf64_exec(struct preloaded_file *amp);
+static int	elf64_obj_exec(struct preloaded_file *amp);
 
 struct file_format amd64_elf = { elf64_loadfile, elf64_exec };
+struct file_format amd64_elf_obj = { elf64_obj_loadfile, elf64_obj_exec };
 
 #define PG_V	0x001
 #define PG_RW	0x002
@@ -116,3 +118,9 @@ elf64_exec(struct preloaded_file *fp)
 
     panic("exec returned");
 }
+
+static int
+elf64_obj_exec(struct preloaded_file *fp)
+{
+	return (EFTYPE);
+}
diff --git a/sys/boot/i386/loader/conf.c b/sys/boot/i386/loader/conf.c
index e312959..1d8bd04 100644
--- a/sys/boot/i386/loader/conf.c
+++ b/sys/boot/i386/loader/conf.c
@@ -83,11 +83,15 @@ struct fs_ops *file_system[] = {
  * rather than reading the file go first.
  */
 extern struct file_format	i386_elf;
+extern struct file_format	i386_elf_obj;
 extern struct file_format	amd64_elf;
+extern struct file_format	amd64_elf_obj;
 
 struct file_format *file_formats[] = {
     &i386_elf,
+    &i386_elf_obj,
     &amd64_elf,
+    &amd64_elf_obj,
     NULL
 };