This parser is needed for kernel boot support on MIPS
and can potentially reused on other platforms.
Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
common/Makefile | 1 +
common/elf.c | 146 ++++++++++++++++++++++++++++++++++++++++++++++++
include/elf.h | 10 ++++
3 files changed, 157 insertions(+)
create mode 100644 common/elf.c
diff --git a/common/Makefile b/common/Makefile
index 1ff7d2370..4fe7eaaf6 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-y += 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..d6a1f8b6a
--- /dev/null
+++ b/common/elf.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
+ */
+
+#include <common.h>
+#include <elf.h>
+#include <memory.h>
+
+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: %x %x\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->buf);
+ 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 <linux/types.h>
+#include <linux/list.h>
//#include <linux/auxvec.h>
//#include <linux/elf-em.h>
#include <asm/elf.h>
@@ -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
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