1 files changed, 245 insertions, 0 deletions
diff --git a/src/lib/rmodule.c b/src/lib/rmodule.c
new file mode 100644
index 0000000000..56d7c6d646
--- /dev/null
+++ b/src/lib/rmodule.c
@@ -0,0 +1,245 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012 ChromeOS Authors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+#include <stdint.h>
+#include <string.h>
+#include <console/console.h>
+#include <rmodule.h>
+
+/* Change this define to get more verbose debugging for module loading. */
+#define PK_ADJ_LEVEL BIOS_NEVER
+
+#if CONFIG_ARCH_X86
+/*
+ * On X86, the only relocations currently allowed are R_386_RELATIVE which
+ * have '0' for the symbol info in the relocation metadata (in r_info).
+ * The reason is that the module is fully linked and just has the relocations'
+ * locations.
+ */
+typedef struct {
+	u32 r_offset;
+	u32 r_info;
+} Elf32_Rel;
+
+#define R_386_RELATIVE 8
+
+#define RELOCTION_ENTRY_SIZE sizeof(Elf32_Rel)
+static inline int rmodule_reloc_offset(const void *reloc)
+{
+	const Elf32_Rel *rel = reloc;
+	return rel->r_offset;
+}
+
+static inline int rmodule_reloc_valid(const void *reloc)
+{
+	const Elf32_Rel *rel = reloc;
+	return (rel->r_info == R_386_RELATIVE);
+}
+
+static inline void *remodule_next_reloc(const void *reloc)
+{
+	const Elf32_Rel *rel = reloc;
+	rel++;
+	return (void *)rel;
+}
+
+#else
+#error Arch needs to add relocation information support for RMODULE
+#endif
+
+static inline int rmodule_is_loaded(const struct rmodule *module)
+{
+	return module->location != NULL;
+}
+
+/* Calculate a loaded program address based on the blob address. */
+static inline void *rmodule_load_addr(const struct rmodule *module,
+                                      u32 blob_addr)
+{
+	char *loc = module->location;
+	return &loc[blob_addr - module->header->module_link_start_address];
+}
+
+/* Initialize a rmodule structure based on raw data. */
+int rmodule_parse(void *ptr, struct rmodule *module)
+{
+	char *base;
+	struct rmodule_header *rhdr;
+
+	base = ptr;
+	rhdr = ptr;
+
+	if (rhdr == NULL)
+		return -1;
+
+	/* Sanity check the raw data. */
+	if (rhdr->magic != RMODULE_MAGIC)
+		return -1;
+	if (rhdr->version != RMODULE_VERSION_1)
+		return -1;
+
+	/* Indicate the module hasn't been loaded yet. */
+	module->location = NULL;
+
+	/* The rmodule only needs a reference to the reloc_header. */
+	module->header = rhdr;
+
+	/* The payload lives after the header. */
+	module->payload = &base[rhdr->payload_begin_offset];
+	module->payload_size = rhdr->payload_end_offset -
+	                       rhdr->payload_begin_offset;
+	module->relocations = &base[rhdr->relocations_begin_offset];
+
+	return 0;
+}
+
+int rmodule_memory_size(const struct rmodule *module)
+{
+	return module->header->module_program_size;
+}
+
+void *rmodule_parameters(const struct rmodule *module)
+{
+	if (!rmodule_is_loaded(module))
+		return NULL;
+
+	/* Indicate if there are no parameters. */
+	if (module->header->parameters_begin == module->header->parameters_end)
+		return NULL;
+
+	return rmodule_load_addr(module, module->header->parameters_begin);
+}
+
+int rmodule_entry_offset(const struct rmodule *module)
+{
+	return module->header->module_entry_point -
+	       module->header->module_link_start_address;
+}
+
+void *rmodule_entry(const struct rmodule *module)
+{
+	if (!rmodule_is_loaded(module))
+		return NULL;
+
+	return rmodule_load_addr(module, module->header->module_entry_point);
+}
+
+static void rmodule_clear_bss(struct rmodule *module)
+{
+	char *begin;
+	int size;
+
+	begin = rmodule_load_addr(module, module->header->bss_begin);
+	size = module->header->bss_end - module->header->bss_begin;
+	memset(begin, 0, size);
+}
+
+static inline int rmodule_number_relocations(const struct rmodule *module)
+{
+	int r;
+
+	r = module->header->relocations_end_offset;
+	r -= module->header->relocations_begin_offset;
+	r /= RELOCTION_ENTRY_SIZE;
+	return r;
+}
+
+static void rmodule_copy_payload(const struct rmodule *module)
+{
+	printk(BIOS_DEBUG, "Loading module at %p with entry %p. "
+	       "filesize: 0x%x memsize: 0x%x\n",
+	       module->location, rmodule_entry(module),
+	       module->payload_size, rmodule_memory_size(module));
+	memcpy(module->location, module->payload, module->payload_size);
+}
+
+static inline u32 *rmodule_adjustment_location(const struct rmodule *module,
+                                               const void *reloc)
+{
+	int reloc_offset;
+
+	/* Don't relocate header field entries -- only program relocations. */
+	reloc_offset = rmodule_reloc_offset(reloc);
+	if (reloc_offset < module->header->module_link_start_address)
+		return NULL;
+
+	return rmodule_load_addr(module, reloc_offset);
+}
+
+static int rmodule_relocate(const struct rmodule *module)
+{
+	int num_relocations;
+	const void *reloc;
+	u32 adjustment;
+
+	/* Each relocation needs to be adjusted relative to the beginning of
+	 * the loaded program. */
+	adjustment = (u32)rmodule_load_addr(module, 0);
+
+	reloc = module->relocations;
+	num_relocations = rmodule_number_relocations(module);
+
+	printk(BIOS_DEBUG, "Processing %d relocs with adjust value of 0x%08x\n",
+	       num_relocations, adjustment);
+
+	while (num_relocations > 0) {
+		u32 *adjust_loc;
+
+		if (!rmodule_reloc_valid(reloc))
+			return -1;
+
+		/* If the adjustment location is non-NULL adjust it. */
+		adjust_loc = rmodule_adjustment_location(module, reloc);
+		if (adjust_loc != NULL) {
+			printk(PK_ADJ_LEVEL, "Adjusting %p: 0x%08x -> 0x%08x\n",
+			       adjust_loc, *adjust_loc,
+			       *adjust_loc + adjustment);
+			*adjust_loc += adjustment;
+		}
+
+		reloc = remodule_next_reloc(reloc);
+		num_relocations--;
+	}
+
+	return 0;
+}
+
+int rmodule_load_alignment(const struct rmodule *module)
+{
+	/* The load alignment is the start of the program's linked address.
+	 * The base address where the program is loaded needs to be a multiple
+	 * of the program's starting link address. That way all data alignment
+	 * in the program is presered. */
+	return module->header->module_link_start_address;
+}
+
+int rmodule_load(void *base, struct rmodule *module)
+{
+	/*
+	 * In order to load the module at a given address, the following steps
+	 * take place:
+	 *  1. Copy payload to base address.
+	 *  2. Clear the bss segment.
+	 *  3. Adjust relocations within the module to new base address.
+	 */
+	module->location = base;
+	rmodule_copy_payload(module);
+	rmodule_clear_bss(module);
+	return rmodule_relocate(module);
+}
+