From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by casper.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fPmNI-00056i-MM for barebox@lists.infradead.org; Mon, 04 Jun 2018 10:06:08 +0000 From: Oleksij Rempel Date: Mon, 4 Jun 2018 12:05:44 +0200 Message-Id: <20180604100546.19140-3-o.rempel@pengutronix.de> In-Reply-To: <20180604100546.19140-1-o.rempel@pengutronix.de> References: <20180604100546.19140-1-o.rempel@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH v3 2/4] add basic ELF parser To: barebox@lists.infradead.org Cc: Oleksij Rempel This parser is needed for kernel boot support on MIPS and can potentially reused on other platforms. Signed-off-by: Oleksij Rempel --- common/Kconfig | 3 + common/Makefile | 1 + common/elf.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++++ include/elf.h | 10 ++++ 4 files changed, 159 insertions(+) create mode 100644 common/elf.c diff --git a/common/Kconfig b/common/Kconfig index b7000c4d7..afb150193 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -46,6 +46,9 @@ config BLOCK config BLOCK_WRITE bool +config ELF + bool + config FILETYPE bool diff --git a/common/Makefile b/common/Makefile index 1ff7d2370..b6284c255 100644 --- a/common/Makefile +++ b/common/Makefile @@ -8,6 +8,7 @@ obj-y += misc.o obj-pbl-y += memsize.o obj-y += resource.o obj-y += bootsource.o +obj-$(CONFIG_ELF) += elf.o obj-y += restart.o obj-y += poweroff.o obj-$(CONFIG_AUTO_COMPLETE) += complete.o diff --git a/common/elf.c b/common/elf.c new file mode 100644 index 000000000..51b29b145 --- /dev/null +++ b/common/elf.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2018 Pengutronix, Oleksij Rempel + */ + +#include +#include +#include + +struct elf_section { + struct list_head list; + struct resource *r; +}; + +static int elf_request_region(struct elf_image *elf, resource_size_t start, + resource_size_t size) +{ + struct list_head *list = &elf->list; + struct resource *r_new; + struct elf_section *r; + + r = xzalloc(sizeof(*r)); + r_new = request_sdram_region("elf_section", start, size); + if (!r_new) { + pr_err("Failed to request region: %pa %pa\n", start, size); + return -EINVAL; + } + + r->r = r_new; + list_add_tail(&r->list, list); + + return 0; +} + +static void elf_release_regions(struct elf_image *elf) +{ + struct list_head *list = &elf->list; + struct elf_section *r, *r_tmp; + + list_for_each_entry_safe(r, r_tmp, list, list) { + release_sdram_region(r->r); + free(r); + } +} + + +static int load_elf_phdr_segment(struct elf_image *elf, void *src, + Elf32_Phdr *phdr) +{ + void *dst = (void *)phdr->p_paddr; + int ret; + + /* we care only about PT_LOAD segments */ + if (phdr->p_type != PT_LOAD) + return 0; + + if (!phdr->p_filesz) + return 0; + + pr_debug("Loading phdr to 0x%p (%i bytes)\n", dst, phdr->p_filesz); + + ret = elf_request_region(elf, (resource_size_t)dst, phdr->p_filesz); + if (ret) + return ret; + + memcpy(dst, src, phdr->p_filesz); + + if (phdr->p_filesz < phdr->p_memsz) + memset(dst + phdr->p_filesz, 0x00, + phdr->p_memsz - phdr->p_filesz); + + return 0; +} + +static int load_elf_image_phdr(struct elf_image *elf) +{ + void *buf = elf->buf; + Elf32_Ehdr *ehdr = buf; + Elf32_Phdr *phdr = (Elf32_Phdr *)(buf + ehdr->e_phoff); + int i, ret; + + elf->entry = ehdr->e_entry; + + for (i = 0; i < ehdr->e_phnum; ++i) { + void *src = buf + phdr->p_offset; + + ret = load_elf_phdr_segment(elf, src, phdr); + /* in case of error elf_load_image() caller should clean up and + * call elf_release_image() */ + if (ret) + return ret; + + ++phdr; + } + + return 0; +} + +static int elf_check_image(void *buf) +{ + Elf32_Ehdr *ehdr = (Elf32_Ehdr *)buf; + + if (strncmp(buf, ELFMAG, SELFMAG)) { + pr_err("ELF magic not found.\n"); + return -EINVAL; + } + + if (ehdr->e_type != ET_EXEC) { + pr_err("Non EXEC ELF image.\n"); + return -ENOEXEC; + } + + return 0; +} + +struct elf_image *elf_load_image(void *buf) +{ + struct elf_image *elf; + int ret; + + elf = xzalloc(sizeof(*elf)); + + INIT_LIST_HEAD(&elf->list); + + elf->buf = buf; + + ret = elf_check_image(buf); + if (ret) + return ERR_PTR(ret); + + ret = load_elf_image_phdr(elf); + if (ret) { + elf_release_image(elf); + return ERR_PTR(ret); + } + + return elf; +} + +void elf_release_image(struct elf_image *elf) +{ + elf_release_regions(elf); + + free(elf); +} diff --git a/include/elf.h b/include/elf.h index ebcec7db0..92c8d9c12 100644 --- a/include/elf.h +++ b/include/elf.h @@ -2,6 +2,7 @@ #define _LINUX_ELF_H #include +#include //#include //#include #include @@ -397,4 +398,13 @@ static inline void arch_write_notes(struct file *file) { } #define ELF_CORE_WRITE_EXTRA_NOTES arch_write_notes(file) #endif /* ARCH_HAVE_EXTRA_ELF_NOTES */ +struct elf_image { + struct list_head list; + unsigned long entry; + void *buf; +}; + +struct elf_image *elf_load_image(void *buf); +void elf_release_image(struct elf_image *elf); + #endif /* _LINUX_ELF_H */ -- 2.17.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox