I do not know whether it is possible to add one element in structure grub_elf_file structure to identify ELF type (ELFCLASS32/ELFCLASS64) and ELF machine type, this element can be set at function grub_elf_open.
Thanks Bibo,mao >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] On Behalf Of Hollis >Blanchard >Sent: 2006年10月14日 6:38 >To: grub-devel >Subject: [PATCH] generic ELF loading > >This patch adds generic ELF loading infrastructure for both 32-bit and >64-bit ELF. It provides an "iterate" function for program headers, and a >"load" function for convenience. > >I have converted the PowerPC Linux loader to use this infrastructure >(see next mail), and possibly the i386 multiboot loader as well (though >I will need others to test it). The module loader looks a little more >annoying because it actually loads *sections*, not segments. > >I will be away next week but intend to commit this soon after, so please >review. > >This code is literally duplicated, once for 32-bit and once for 64-bit. >I'm trying to come up with a better way of doing that, and I'm >considering something like this: > > elf32.c: > #define Elf_Ehdr Elf32_Ehdr > #define Elf_Phdr Elf32_Phdr > #include "elfclass.c" > > elf64.c: > #define Elf_Ehdr Elf64_Ehdr > #define Elf_Phdr Elf64_Phdr > #include "elfclass.c" > >If you strongly object to #including C files, or have a better way of >doing this, please speak up. > >-Hollis > >diff -r b53dfa2812ad include/grub/elfload.h >--- /dev/null Thu Jan 01 00:00:00 1970 +0000 >+++ b/include/grub/elfload.h Fri Oct 13 16:23:22 2006 -0500 >@@ -0,0 +1,57 @@ >+/* >+ * GRUB -- GRand Unified Bootloader >+ * Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc. >+ * >+ * 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; either version 2 of the License, or >+ * (at your option) any later version. >+ * >+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA. >+ */ >+ >+#ifndef GRUB_ELFLOAD_HEADER >+#define GRUB_ELFLOAD_HEADER 1 >+ >+#include <grub/err.h> >+#include <grub/elf.h> >+#include <grub/file.h> >+#include <grub/symbol.h> >+#include <grub/types.h> >+ >+struct grub_elf_file >+{ >+ grub_file_t file; >+ union { >+ Elf64_Ehdr ehdr64; >+ Elf32_Ehdr ehdr32; >+ } ehdr; >+ void *phdrs; >+}; >+typedef struct grub_elf_file *grub_elf_t; >+ >+grub_elf_t EXPORT_FUNC(grub_elf_open) (const char *name); >+grub_err_t EXPORT_FUNC(grub_elf_close) (grub_elf_t elf); >+ >+int EXPORT_FUNC(grub_elf_is_elf32) (grub_elf_t elf); >+grub_err_t EXPORT_FUNC(grub_elf32_phdr_iterate) (grub_elf_t elf, >+ int (*hook) (grub_elf_t, Elf32_Phdr *, void *), >+ void *hook_arg); >+grub_err_t EXPORT_FUNC(grub_elf32_load) (grub_elf_t elf, >+ int (*) (Elf32_Phdr *)); >+ >+int EXPORT_FUNC(grub_elf_is_elf64) (grub_elf_t elf); >+grub_err_t EXPORT_FUNC(grub_elf64_phdr_iterate) (grub_elf_t elf, >+ int (*hook) (grub_elf_t, Elf64_Phdr *, void *), >+ void *hook_arg); >+grub_err_t EXPORT_FUNC(grub_elf64_load) (grub_elf_t elf, >+ int (*) (Elf64_Phdr *)); >+ >+#endif /* ! GRUB_ELFLOAD_HEADER */ >diff -r b53dfa2812ad kern/elf.c >--- /dev/null Thu Jan 01 00:00:00 1970 +0000 >+++ b/kern/elf.c Fri Oct 13 16:23:22 2006 -0500 >@@ -0,0 +1,280 @@ >+/* elf.c - load ELF files */ >+/* >+ * GRUB -- GRand Unified Bootloader >+ * Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc. >+ * >+ * 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; either version 2 of the License, or >+ * (at your option) any later version. >+ * >+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA. >+ */ >+ >+#include <grub/err.h> >+#include <grub/elf.h> >+#include <grub/elfload.h> >+#include <grub/file.h> >+#include <grub/misc.h> >+#include <grub/mm.h> >+ >+/* Check if EHDR is a valid ELF header. */ >+static grub_err_t >+grub_elf_check_header (grub_elf_t elf) >+{ >+ Elf32_Ehdr *e = &elf->ehdr.ehdr32; >+ >+ if (e->e_ident[EI_MAG0] != ELFMAG0 >+ || e->e_ident[EI_MAG1] != ELFMAG1 >+ || e->e_ident[EI_MAG2] != ELFMAG2 >+ || e->e_ident[EI_MAG3] != ELFMAG3 >+ || e->e_ident[EI_VERSION] != EV_CURRENT >+ || e->e_version != EV_CURRENT) >+ return grub_error (GRUB_ERR_BAD_OS, "invalid arch independent ELF >magic"); >+ >+ return GRUB_ERR_NONE; >+} >+ >+grub_err_t >+grub_elf_close (grub_elf_t elf) >+{ >+ grub_file_t file = elf->file; >+ >+ grub_free (elf->phdrs); >+ grub_free (elf); >+ >+ if (file) >+ grub_file_close (file); >+ >+ return grub_errno; >+} >+ >+grub_elf_t >+grub_elf_open (const char *name) >+{ >+ grub_elf_t elf; >+ >+ elf = grub_malloc (sizeof (*elf)); >+ if (! elf) >+ return 0; >+ >+ elf->file = 0; >+ elf->phdrs = 0; >+ >+ elf->file = grub_file_open (name); >+ if (! elf->file) >+ goto fail; >+ >+ if (grub_file_read (elf->file, (char *) &elf->ehdr, sizeof (elf->ehdr)) >+ != sizeof (elf->ehdr)) >+ { >+ grub_error (GRUB_ERR_READ_ERROR, "Cannot read ELF header."); >+ goto fail; >+ } >+ >+ if (grub_elf_check_header (elf)) >+ goto fail; >+ >+ return elf; >+ >+fail: >+ grub_elf_close (elf); >+ return 0; >+} >+ >+ > > >+/* 32-bit */ >+ >+int >+grub_elf_is_elf32 (grub_elf_t elf) >+{ >+ return elf->ehdr.ehdr32.e_ident[EI_CLASS] == ELFCLASS32; >+} >+ >+typedef int (*grub_elf32_load_hook_t) (Elf32_Phdr *phdr); >+ >+static int >+grub_elf32_load_segment (grub_elf_t elf, Elf32_Phdr *phdr, >+ void *hook) >+{ >+ grub_elf32_load_hook_t load_hook = (grub_elf32_load_hook_t) hook; >+ >+ if (phdr->p_type != PT_LOAD) >+ return 0; >+ >+ if (load_hook && load_hook (phdr)) >+ return 1; >+ >+ grub_dprintf ("loader", "Loading segment at %llx, size 0x%llx\n", >+ (unsigned long long) phdr->p_paddr, >+ (unsigned long long) phdr->p_filesz); >+ >+ if (grub_file_seek (elf->file, phdr->p_offset) == (grub_off_t) -1) >+ { >+ return grub_error (GRUB_ERR_BAD_OS, "Invalid offset in program >header"); >+ } >+ >+ if (grub_file_read (elf->file, (void *) (long) phdr->p_paddr, >phdr->p_filesz) >+ != (grub_ssize_t) phdr->p_filesz) >+ { >+ return grub_error (GRUB_ERR_BAD_OS, "Couldn't load segment"); >+ } >+ >+ if (phdr->p_filesz < phdr->p_memsz) >+ grub_memset ((void *) (unsigned long) (phdr->p_paddr + phdr->p_filesz), >+ 0, phdr->p_memsz - phdr->p_filesz); >+ >+ return 0; >+} >+ >+static grub_err_t >+grub_elf32_load_phdrs (grub_elf_t elf) >+{ >+ grub_ssize_t phdrs_size; >+ >+ phdrs_size = elf->ehdr.ehdr32.e_phnum * elf->ehdr.ehdr32.e_phentsize; >+ >+ grub_dprintf ("elf", "loading program headers: offset 0x%llx, size 0x%x\n", >+ (unsigned long long) elf->ehdr.ehdr32.e_phoff, >+ phdrs_size); >+ >+ elf->phdrs = grub_malloc (phdrs_size); >+ if (! elf->phdrs) >+ return grub_errno; >+ >+ if ((grub_file_seek (elf->file, elf->ehdr.ehdr32.e_phoff) == (grub_off_t) >-1) >+ || (grub_file_read (elf->file, elf->phdrs, phdrs_size) != phdrs_size)) >+ return grub_error (GRUB_ERR_READ_ERROR, "Cannot read program headers"); >+ >+ return GRUB_ERR_NONE; >+} >+ >+grub_err_t >+grub_elf32_phdr_iterate (grub_elf_t elf, >+ int (*hook) (grub_elf_t, Elf32_Phdr *, void *), >+ void *hook_arg) >+{ >+ Elf32_Phdr *phdrs; >+ unsigned int i; >+ >+ if (! elf->phdrs) >+ if (grub_elf32_load_phdrs (elf)) >+ return grub_errno; >+ >+ phdrs = (Elf32_Phdr *) elf->phdrs; >+ for (i = 0; i < elf->ehdr.ehdr32.e_phnum; i++) >+ if (hook (elf, phdrs + i, hook_arg)) >+ break; >+ >+ return grub_errno; >+} >+ >+/* Load every loadable segment into memory. */ >+grub_err_t >+grub_elf32_load (grub_elf_t elf, int (*phdr_hook) (Elf32_Phdr *)) >+{ >+ return grub_elf32_phdr_iterate (elf, grub_elf32_load_segment, >+ phdr_hook); >+} >+ >+ > > >+/* 64-bit */ >+ >+int >+grub_elf_is_elf64 (grub_elf_t elf) >+{ >+ return elf->ehdr.ehdr64.e_ident[EI_CLASS] == ELFCLASS64; >+} >+ >+typedef int (*grub_elf64_load_hook_t) (Elf64_Phdr *phdr); >+ >+static int >+grub_elf64_load_segment (grub_elf_t elf, Elf64_Phdr *phdr, >+ void *hook) >+{ >+ grub_elf64_load_hook_t load_hook = (grub_elf64_load_hook_t) hook; >+ >+ if (phdr->p_type != PT_LOAD) >+ return 0; >+ >+ if (load_hook && load_hook (phdr)) >+ return 1; >+ >+ grub_dprintf ("loader", "Loading segment at %llx, size 0x%llx\n", >+ (unsigned long long) phdr->p_paddr, >+ (unsigned long long) phdr->p_filesz); >+ >+ if (grub_file_seek (elf->file, phdr->p_offset) == (grub_off_t) -1) >+ { >+ return grub_error (GRUB_ERR_BAD_OS, "Invalid offset in program >header"); >+ } >+ >+ if (grub_file_read (elf->file, (void *) (long) phdr->p_paddr, >phdr->p_filesz) >+ != (grub_ssize_t) phdr->p_filesz) >+ { >+ return grub_error (GRUB_ERR_BAD_OS, "Couldn't load segment"); >+ } >+ >+ if (phdr->p_filesz < phdr->p_memsz) >+ grub_memset ((void *) (unsigned long) (phdr->p_paddr + phdr->p_filesz), >+ 0, phdr->p_memsz - phdr->p_filesz); >+ >+ return 0; >+} >+ >+static grub_err_t >+grub_elf64_load_phdrs (grub_elf_t elf) >+{ >+ grub_ssize_t phdrs_size; >+ >+ phdrs_size = elf->ehdr.ehdr64.e_phnum * elf->ehdr.ehdr64.e_phentsize; >+ >+ grub_dprintf ("elf", "loading program headers: offset 0x%llx, size 0x%x\n", >+ (unsigned long long) elf->ehdr.ehdr64.e_phoff, >+ phdrs_size); >+ >+ elf->phdrs = grub_malloc (phdrs_size); >+ if (! elf->phdrs) >+ return grub_errno; >+ >+ if ((grub_file_seek (elf->file, elf->ehdr.ehdr64.e_phoff) == (grub_off_t) >-1) >+ || (grub_file_read (elf->file, elf->phdrs, phdrs_size) != phdrs_size)) >+ return grub_error (GRUB_ERR_READ_ERROR, "Cannot read program headers"); >+ >+ return GRUB_ERR_NONE; >+} >+ >+grub_err_t >+grub_elf64_phdr_iterate (grub_elf_t elf, >+ int (*hook) (grub_elf_t, Elf64_Phdr *, void *), >+ void *hook_arg) >+{ >+ Elf64_Phdr *phdrs; >+ unsigned int i; >+ >+ if (! elf->phdrs) >+ if (grub_elf64_load_phdrs (elf)) >+ return grub_errno; >+ >+ phdrs = (Elf64_Phdr *) elf->phdrs; >+ for (i = 0; i < elf->ehdr.ehdr64.e_phnum; i++) >+ if (hook (elf, phdrs + i, hook_arg)) >+ break; >+ >+ return grub_errno; >+} >+ >+/* Load every loadable segment into memory. */ >+grub_err_t >+grub_elf64_load (grub_elf_t elf, int (*phdr_hook) (Elf64_Phdr *)) >+{ >+ return grub_elf64_phdr_iterate (elf, grub_elf64_load_segment, >+ phdr_hook); >+} > > > > >_______________________________________________ >Grub-devel mailing list >Grub-devel@gnu.org >http://lists.gnu.org/mailman/listinfo/grub-devel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
