elf: remove long-since-obsolete shallow module machinery

Meant to handle symbols exported from the core, but we just
pregenerate the dynamic section instead.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

6 files changed, 5 insertions, 223 deletions

diff --git a/com32/include/sys/exec.h b/com32/include/sys/exec.h
index ac05c276..f4559d15 100644
--- a/com32/include/sys/exec.h
+++ b/com32/include/sys/exec.h
@@ -34,27 +34,6 @@
 extern int spawn_load(const char *name, int argc, char **argv);
 
 /**
- * exec_init - Initialize the dynamic execution environment.
- *
- * Among others, it initializes the module subsystem and loads the root
- * module into memory. You should note the difference between the module
- * management API, and the execution API:
- *  - the module system is a static one - it only manages the data structures
- *  and their relationship. It does not describe the way modules are executed,
- *  when and how they are loaded/unloaded, etc. It acts as a service layer for
- *  the execution API.
- *  - the execution environment is the dynamic part of the SYSLINUX dynamic
- *  module API - it implements the behavior of the modules: it
- *  triggers the execution of initialization and termination functions for
- *  libraries, executes the modules marked as executable, handles dynamic
- *  memory cleanup, etc. In other words, at this layer the code and data
- *  loaded by the lower module layer gets to be executed by the CPU,
- *  thus becoming part of the SYSLINUX environment.
- */
-extern int exec_init(void);
-
-
-/**
  * spawnv - Executes a program in the current environment.
  * @name:	the name of the program to spawn, including the extension
  * 			(e.g. 'hello.c32')
diff --git a/com32/include/sys/module.h b/com32/include/sys/module.h
index ea11a88f..a18561a9 100644
--- a/com32/include/sys/module.h
+++ b/com32/include/sys/module.h
@@ -246,18 +246,6 @@ extern int module_load(struct elf_module *module);
 
 
 /**
- * module_load_shallow - loads a shallow ELF module into memory.
- * @module:	the module descriptor returned by module_alloc.
- *
- * The function reads the module file, checks whether the file has a valid
- * structure, then loads into memory the module metadata. The metadata currently
- * contains a symbol table that describes code & data allocated by other means.
- * Its current use is to describe the root COM32 module to the rest of the
- * module subsystem.
- */
-extern int module_load_shallow(struct elf_module *module, Elf32_Addr base_addr);
-
-/**
  * module_unload - unloads the module from the system.
  * @module: the module descriptor structure.
  *
diff --git a/com32/lib/Makefile b/com32/lib/Makefile
index dd1ef7c6..d979ab43 100644
--- a/com32/lib/Makefile
+++ b/com32/lib/Makefile
@@ -86,7 +86,7 @@ LIBENTRY_OBJS = \
 
 LIBMODULE_OBJS = \
 	sys/module/common.o sys/module/elf_module.o		\
-	sys/module/shallow_module.o	sys/module/elfutils.o	\
+	sys/module/elfutils.o					\
 	sys/module/exec.o
 
 LIBGCC_OBJS = \
diff --git a/com32/lib/sys/module/exec.c b/com32/lib/sys/module/exec.c
index ac9ca79a..2b3a4c09 100644
--- a/com32/lib/sys/module/exec.c
+++ b/com32/lib/sys/module/exec.c
@@ -18,32 +18,8 @@
 
 #define DBG_PRINT(fmt, args...) dprintf("[EXEC] " fmt, ##args)
 
-static struct elf_module    *mod_root = NULL;
 struct elf_module *__syslinux_current = NULL;
 
-int exec_init(void)
-{
-	int res;
-
-	res = modules_init();
-	if (res != 0)
-		return res;
-
-	// Load the root module
-	mod_root = module_alloc(EXEC_ROOT_NAME);
-
-	if (mod_root == NULL)
-		return -1;
-
-	res = module_load_shallow(mod_root, 0);
-	if (res != 0) {
-		mod_root = NULL;
-		return res;
-	}
-
-	return 0;
-}
-
 int get_module_type(struct elf_module *module)
 {
 	if(module->main_func) return EXEC_MODULE;
diff --git a/com32/lib/sys/module/shallow_module.c b/com32/lib/sys/module/shallow_module.c
deleted file mode 100644
index 8a88e403..00000000
--- a/com32/lib/sys/module/shallow_module.c
+++ /dev/null
@@ -1,161 +0,0 @@
-/*
- * shallow_module.c
- *
- *  Created on: Aug 11, 2008
- *      Author: Stefan Bucur <stefanb@zytor.com>
- */
-
-
-#include <string.h>
-#include <sys/module.h>
-
-#include "common.h"
-#include "elfutils.h"
-
-
-static int check_header_shallow(Elf32_Ehdr *elf_hdr) {
-	int res;
-
-	res = check_header_common(elf_hdr);
-
-	if (res != 0)
-		return res;
-
-	if (elf_hdr->e_shoff == 0x00000000) {
-		DBG_PRINT("SHT missing\n");
-		return -1;
-	}
-
-	return 0;
-}
-
-static int load_shallow_sections(struct elf_module *module, Elf32_Ehdr *elf_hdr) {
-	int i;
-	int res = 0;
-	char *sht = NULL;
-	char *buffer = NULL;
-	Elf32_Shdr *crt_sht;
-	Elf32_Off buff_offset;
-
-	Elf32_Off min_offset = 0xFFFFFFFF;
-	Elf32_Off max_offset = 0x00000000;
-	Elf32_Word max_align = 0x1;
-
-	Elf32_Off sym_offset = 0xFFFFFFFF;
-	Elf32_Off str_offset = 0xFFFFFFFF;
-
-
-	char *sh_strtable;
-
-	// We buffer the data up to the SHT
-	buff_offset = module->u.l._cr_offset;
-
-	buffer = malloc(elf_hdr->e_shoff - buff_offset);
-	// Get to the SHT
-	image_read(buffer, elf_hdr->e_shoff - buff_offset, module);
-
-	// Load the SHT
-	sht = malloc(elf_hdr->e_shnum * elf_hdr->e_shentsize);
-	image_read(sht, elf_hdr->e_shnum * elf_hdr->e_shentsize, module);
-
-	// Get the string table of the section names
-	crt_sht = (Elf32_Shdr*)(sht + elf_hdr->e_shstrndx * elf_hdr->e_shentsize);
-	sh_strtable = (char*)(buffer + (crt_sht->sh_offset - buff_offset));
-
-	for (i = 0; i < elf_hdr->e_shnum; i++) {
-		crt_sht = (Elf32_Shdr*)(sht + i*elf_hdr->e_shentsize);
-
-		if (strcmp(".symtab", sh_strtable + crt_sht->sh_name) == 0) {
-			// We found the symbol table
-			min_offset = MIN(min_offset, crt_sht->sh_offset);
-			max_offset = MAX(max_offset, crt_sht->sh_offset + crt_sht->sh_size);
-			max_align = MAX(max_align, crt_sht->sh_addralign);
-
-			sym_offset = crt_sht->sh_offset;
-
-			module->syment_size = crt_sht->sh_entsize;
-			module->symtable_size = crt_sht->sh_size / crt_sht->sh_entsize;
-		}
-		if (strcmp(".strtab", sh_strtable + crt_sht->sh_name) == 0) {
-			// We found the string table
-			min_offset = MIN(min_offset, crt_sht->sh_offset);
-			max_offset = MAX(max_offset, crt_sht->sh_offset + crt_sht->sh_size);
-			max_align = MAX(max_align, crt_sht->sh_addralign);
-
-			str_offset = crt_sht->sh_offset;
-
-			module->strtable_size = crt_sht->sh_size;
-		}
-	}
-
-	if (elf_malloc(&module->module_addr, max_align,
-			max_offset - min_offset) != 0) {
-		DBG_PRINT("Could not allocate sections\n");
-		goto out;
-	}
-
-	// Copy the data
-	image_seek(min_offset, module);
-	image_read(module->module_addr, max_offset - min_offset, module);
-
-	// Setup module information
-	module->module_size = max_offset - min_offset;
-	module->str_table = (char *)module->module_addr + (str_offset - min_offset);
-	module->sym_table = (char *)module->module_addr + (sym_offset - min_offset);
-
-out:
-	// Release the SHT
-	if (sht != NULL)
-		free(sht);
-
-	// Release the buffer
-	if (buffer != NULL)
-		free(buffer);
-
-	return res;
-}
-
-
-int module_load_shallow(struct elf_module *module, Elf32_Addr base_addr) {
-	int res;
-	Elf32_Ehdr elf_hdr;
-
-	// Do not allow duplicate modules
-	if (module_find(module->name) != NULL) {
-		DBG_PRINT("Module already loaded.\n");
-		return -1;
-	}
-
-	res = image_load(module);
-
-	if (res < 0)
-		return res;
-
-	module->shallow = 1;
-
-	CHECKED(res, image_read(&elf_hdr, sizeof(Elf32_Ehdr), module), error);
-
-	// Checking the header signature and members
-	CHECKED(res, check_header_shallow(&elf_hdr), error);
-
-	CHECKED(res, load_shallow_sections(module, &elf_hdr), error);
-	module->base_addr = base_addr;
-
-	// Check the symbols for duplicates / missing definitions
-	CHECKED(res, check_symbols(module), error);
-
-	// Add the module at the beginning of the module list
-	list_add(&module->list, &modules_head);
-
-	// The file image is no longer needed
-	image_unload(module);
-
-	DBG_PRINT("SHALLOW MODULE %s LOADED SUCCESSFULLY\n", module->name);
-
-	return 0;
-
-error:
-	image_unload(module);
-
-	return res;
-}
diff --git a/core/elflink/load_env32.c b/core/elflink/load_env32.c
index 7c0afacf..7a6b08fb 100644
--- a/core/elflink/load_env32.c
+++ b/core/elflink/load_env32.c
@@ -50,10 +50,10 @@ struct elf_module core_module = {
 };
 
 /*
-	Initializes the module subsystem by taking the core module ( shallow module ) and placing
-	it on top of the modules_head_list. Since the core module is initialized when declared
-	we technically don't need the exec_init() and module_load_shallow() procedures
-*/
+ * Initializes the module subsystem by taking the core module
+ * (preinitialized shallow module) and placing it on top of the
+ * modules_head_list.
+ */
 void init_module_subsystem(struct elf_module *module)
 {
     list_add(&module->list, &modules_head);