cbfstool: Add option to ignore section in add-stage
Allow add-stage to have an optional parameter for ignoring any section. This is
required to ensure proper operation of elf_to_stage in case of loadable segments
with zero filesize.
Change-Id: I49ad62c2a4260ab9cec173c80c0f16923fc66c79
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: http://review.coreboot.org/7304
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
diff --git a/util/cbfstool/cbfs-mkstage.c b/util/cbfstool/cbfs-mkstage.c
index 3da0836..8459334 100644
--- a/util/cbfstool/cbfs-mkstage.c
+++ b/util/cbfstool/cbfs-mkstage.c
@@ -28,16 +28,79 @@
#include "common.h"
#include "cbfs.h"
+/* Checks if program segment contains the ignored section */
+static int is_phdr_ignored(Elf64_Phdr *phdr, Elf64_Shdr *shdr)
+{
+ /* If no ignored section, return false. */
+ if (shdr == NULL)
+ return 0;
+
+ Elf64_Addr sh_start = shdr->sh_addr;
+ Elf64_Addr sh_end = shdr->sh_addr + shdr->sh_size;
+ Elf64_Addr ph_start = phdr->p_vaddr;
+ Elf64_Addr ph_end = phdr->p_vaddr + phdr->p_memsz;
+
+ /* Return true only if section occupies whole of segment. */
+ if ((sh_start == ph_start) && (sh_end == ph_end)) {
+ DEBUG("Ignoring program segment at %p\n", (void *)ph_start);
+ return 1;
+ }
+
+ /* If shdr intersects phdr at all, its a conflict */
+ if (((sh_start >= ph_start) && (sh_start <= ph_end)) ||
+ ((sh_end >= ph_start) && (sh_end <= ph_end))) {
+ ERROR("Conflicting sections in segment\n");
+ exit(1);
+ }
+
+ /* Program header doesn't need to be ignored. */
+ return 0;
+}
+
+/* Find section header based on ignored section name */
+static Elf64_Shdr *find_ignored_section_header(struct parsed_elf *pelf,
+ const char *ignore_section)
+{
+ int i;
+ const char *shstrtab;
+
+ /* No section needs to be ignored */
+ if (ignore_section == NULL)
+ return NULL;
+
+ DEBUG("Section to be ignored: %s\n", ignore_section);
+
+ /* Get pointer to string table */
+ shstrtab = buffer_get(pelf->strtabs[pelf->ehdr.e_shstrndx]);
+
+ for (i = 0; i < pelf->ehdr.e_shnum; i++) {
+ Elf64_Shdr *shdr;
+ const char *section_name;
+
+ shdr = &pelf->shdr[i];
+ section_name = &shstrtab[shdr->sh_name];
+
+ /* If section name matches ignored string, return shdr */
+ if (strcmp(section_name, ignore_section) == 0)
+ return shdr;
+ }
+
+ /* No section matches ignore string */
+ return NULL;
+}
+
/* returns size of result, or -1 if error.
* Note that, with the new code, this function
* works for all elf files, not just the restricted set.
*/
int parse_elf_to_stage(const struct buffer *input, struct buffer *output,
- uint32_t arch, comp_algo algo, uint32_t *location)
+ uint32_t arch, comp_algo algo, uint32_t *location,
+ const char *ignore_section)
{
struct parsed_elf pelf;
Elf64_Phdr *phdr;
Elf64_Ehdr *ehdr;
+ Elf64_Shdr *shdr_ignored;
char *buffer;
struct buffer outheader;
int ret = -1;
@@ -62,8 +125,20 @@
ehdr = &pelf.ehdr;
phdr = &pelf.phdr[0];
+ /* Find the section header corresponding to ignored-section */
+ shdr_ignored = find_ignored_section_header(&pelf, ignore_section);
+
+ if (ignore_section && (shdr_ignored == NULL))
+ WARN("Ignore section not found\n");
+
headers = ehdr->e_phnum;
+ /* Ignore the program header containing ignored section */
+ for (i = 0; i < headers; i++) {
+ if (is_phdr_ignored(&phdr[i], shdr_ignored))
+ phdr[i].p_type = PT_NULL;
+ }
+
data_start = ~0;
data_end = 0;
mem_end = 0;