int mod_loadshdrs(FAR struct mod_loadinfo_s *loadinfo)
{
size_t shdrsize;
int ret;
DEBUGASSERT(loadinfo->shdr == NULL);
/* Verify that there are sections */
if (loadinfo->ehdr.e_shnum < 1)
{
serr("ERROR: No sections(?)\n");
return -EINVAL;
}
/* Get the total size of the section header table */
shdrsize = (size_t)loadinfo->ehdr.e_shentsize * (size_t)loadinfo->ehdr.e_shnum;
if (loadinfo->ehdr.e_shoff + shdrsize > loadinfo->filelen)
{
serr("ERROR: Insufficent space in file for section header table\n");
return -ESPIPE;
}
/* Allocate memory to hold a working copy of the sector header table */
loadinfo->shdr = (FAR FAR Elf32_Shdr *)kmm_malloc(shdrsize);
if (!loadinfo->shdr)
{
serr("ERROR: Failed to allocate the section header table. Size: %ld\n",
(long)shdrsize);
return -ENOMEM;
}
/* Read the section header table into memory */
ret = mod_read(loadinfo, (FAR uint8_t *)loadinfo->shdr, shdrsize,
loadinfo->ehdr.e_shoff);
if (ret < 0)
{
serr("ERROR: Failed to read section header table: %d\n", ret);
}
return ret;
}
static inline int mod_loadfile(FAR struct mod_loadinfo_s *loadinfo)
{
FAR uint8_t *text;
FAR uint8_t *data;
FAR uint8_t **pptr;
int ret;
int i;
/* Read each section into memory that is marked SHF_ALLOC + SHT_NOBITS */
svdbg("Loaded sections:\n");
text = (FAR uint8_t *)loadinfo->textalloc;
data = (FAR uint8_t *)loadinfo->datastart;
for (i = 0; i < loadinfo->ehdr.e_shnum; i++)
{
FAR Elf32_Shdr *shdr = &loadinfo->shdr[i];
/* SHF_ALLOC indicates that the section requires memory during
* execution */
if ((shdr->sh_flags & SHF_ALLOC) == 0)
{
continue;
}
/* SHF_WRITE indicates that the section address space is write-
* able
*/
if ((shdr->sh_flags & SHF_WRITE) != 0)
{
pptr = &data;
}
else
{
pptr = &text;
}
/* SHT_NOBITS indicates that there is no data in the file for the
* section.
*/
if (shdr->sh_type != SHT_NOBITS)
{
/* Read the section data from sh_offset to the memory region */
ret = mod_read(loadinfo, *pptr, shdr->sh_size, shdr->sh_offset);
if (ret < 0)
{
sdbg("ERROR: Failed to read section %d: %d\n", i, ret);
return ret;
}
}
/* If there is no data in an allocated section, then the allocated
* section must be cleared.
*/
else
{
memset(*pptr, 0, shdr->sh_size);
}
/* Update sh_addr to point to copy in memory */
svdbg("%d. %08lx->%08lx\n", i,
(unsigned long)shdr->sh_addr, (unsigned long)*pptr);
shdr->sh_addr = (uintptr_t)*pptr;
/* Setup the memory pointer for the next time through the loop */
*pptr += ELF_ALIGNUP(shdr->sh_size);
}
return OK;
}
static inline int mod_sectname(FAR struct mod_loadinfo_s *loadinfo,
FAR const Elf32_Shdr *shdr)
{
FAR Elf32_Shdr *shstr;
FAR uint8_t *buffer;
off_t offset;
size_t readlen;
size_t bytesread;
int shstrndx;
int ret;
/* Get the section header table index of the entry associated with the
* section name string table. If the file has no section name string table,
* this member holds the value SH_UNDEF.
*/
shstrndx = loadinfo->ehdr.e_shstrndx;
if (shstrndx == SHN_UNDEF)
{
serr("ERROR: No section header string table\n");
return -EINVAL;
}
/* Get the section name string table section header */
shstr = &loadinfo->shdr[shstrndx];
/* Get the file offset to the string that is the name of the section. This
* is the sum of:
*
* shstr->sh_offset: The file offset to the first byte of the section
* header string table data.
* shdr->sh_name: The offset to the name of the section in the section
* name table
*/
offset = shstr->sh_offset + shdr->sh_name;
/* Loop until we get the entire section name into memory */
buffer = loadinfo->iobuffer;
bytesread = 0;
for (; ; )
{
/* Get the number of bytes to read */
readlen = loadinfo->buflen - bytesread;
if (offset + readlen > loadinfo->filelen)
{
if (loadinfo->filelen <= offset)
{
serr("ERROR: At end of file\n");
return -EINVAL;
}
readlen = loadinfo->filelen - offset;
}
/* Read that number of bytes into the array */
buffer = &loadinfo->iobuffer[bytesread];
ret = mod_read(loadinfo, buffer, readlen, offset);
if (ret < 0)
{
serr("ERROR: Failed to read section name: %d\n", ret);
return ret;
}
bytesread += readlen;
/* Did we read the NUL terminator? */
if (memchr(buffer, '\0', readlen) != NULL)
{
/* Yes, the buffer contains a NUL terminator. */
return OK;
}
/* No.. then we have to read more */
ret = mod_reallocbuffer(loadinfo, CONFIG_MODULE_BUFFERINCR);
if (ret < 0)
{
serr("ERROR: mod_reallocbuffer failed: %d\n", ret);
return ret;
}
}
/* We will not get here */
return OK;
}
int mod_initialize(FAR const char *filename,
FAR struct mod_loadinfo_s *loadinfo)
{
int ret;
svdbg("filename: %s loadinfo: %p\n", filename, loadinfo);
/* Clear the load info structure */
memset(loadinfo, 0, sizeof(struct mod_loadinfo_s));
/* Get the length of the file. */
ret = mod_filelen(loadinfo, filename);
if (ret < 0)
{
sdbg("mod_filelen failed: %d\n", ret);
return ret;
}
/* Open the binary file for reading (only) */
loadinfo->filfd = open(filename, O_RDONLY);
if (loadinfo->filfd < 0)
{
int errval = errno;
sdbg("Failed to open ELF binary %s: %d\n", filename, errval);
return -errval;
}
/* Read the ELF ehdr from offset 0 */
ret = mod_read(loadinfo, (FAR uint8_t *)&loadinfo->ehdr,
sizeof(Elf32_Ehdr), 0);
if (ret < 0)
{
sdbg("Failed to read ELF header: %d\n", ret);
return ret;
}
mod_dumpbuffer("ELF header", (FAR const uint8_t *)&loadinfo->ehdr,
sizeof(Elf32_Ehdr));
/* Verify the ELF header */
ret = mod_verifyheader(&loadinfo->ehdr);
if (ret < 0)
{
/* This may not be an error because we will be called to attempt loading
* EVERY binary. If mod_verifyheader() does not recognize the ELF header,
* it will -ENOEXEC whcih simply informs the system that the file is not an
* ELF file. mod_verifyheader() will return other errors if the ELF header
* is not correctly formed.
*/
sdbg("Bad ELF header: %d\n", ret);
return ret;
}
return OK;
}
