//---
//	fxBoot:loader:header - Check ELF header
//---
#include "fxBoot/hypervisor.h"
#include "fxBoot/terminal.h"
#include "fxBoot/fs/smemfs.h"
#include "fxBoot/elf.h"

#include "./src/hypervisor/internal/elf.h"

/* error string list */
const struct hel_error_db header_error_db[] = {
	{.id = hel_header_valid,         .strerror = "valid"},
	{.id = hel_header_size_error,    .strerror = "size error"},
	{.id = hel_header_magic_error,   .strerror = "magic error"},
	{.id = hel_header_class_error,   .strerror = "class error"},
	{.id = hel_header_indent_error,  .strerror = "indent error"},
	{.id = hel_header_type_error,    .strerror = "type error"},
	{.id = hel_header_machine_error, .strerror = "machine error"},
	{.id = hel_header_version_error, .strerror = "version error"},
	{.id = 0xdeb0cad0, .strerror = NULL},
};

/* hypervisor_elf_loader_header_error(): Display header error information */
int hypervisor_elf_loader_header_error(int errnum)
{
	return (hypervisor_elf_loader_error(header_error_db,
						"ELF header", errnum));
}

/* hypervisor_elf_loader_header_get(): Get ELF header and check validity */
int hypervisor_elf_loader_header_get(struct smemfs_inode *inode,
							Elf32_Ehdr *header)
{
	/* try to read the ELF header */
	if (smemfs_pread(inode, header, sizeof(*header), 0) != sizeof(*header))
		return (hel_header_size_error);

	/* Check magic number */
	if (header->e_ident[EI_MAG0] != ELFMAG0
	||  header->e_ident[EI_MAG1] != ELFMAG1
	||  header->e_ident[EI_MAG2] != ELFMAG2
	||  header->e_ident[EI_MAG3] != ELFMAG3) {
		return (hel_header_magic_error);
	}

	/* Check class */
	if (header->e_ident[EI_CLASS] != ELFCLASS32)
		return (hel_header_class_error);

	/* Check data encoding */
	if (header->e_ident[EI_DATA] != ELFDATA2MSB)
		return (hel_header_indent_error);

	/* Check ELF type */
	if (header->e_type != ET_DYN && header->e_type != ET_EXEC)
		return (hel_header_type_error);

	/* Check ELF specifique instruction */
	if (header->e_machine != EM_SH)
		return (hel_header_machine_error);

	/* Check ELF version */
	if (header->e_version != EV_CURRENT)
		return (hel_header_version_error);
	return (hel_header_valid);
}

/* hypervisor_elf_loader_header_check(): Check ELF header validity */
int hypervisor_elf_loader_header_check(struct smemfs_inode *inode)
{
	Elf32_Ehdr header;
	return (hypervisor_elf_loader_header_get(inode, &header));
}