summaryrefslogtreecommitdiff
path: root/libre-testing/syslinux/syslinux-6.02-fix-efi-ovmf.patch
diff options
context:
space:
mode:
Diffstat (limited to 'libre-testing/syslinux/syslinux-6.02-fix-efi-ovmf.patch')
-rw-r--r--libre-testing/syslinux/syslinux-6.02-fix-efi-ovmf.patch621
1 files changed, 621 insertions, 0 deletions
diff --git a/libre-testing/syslinux/syslinux-6.02-fix-efi-ovmf.patch b/libre-testing/syslinux/syslinux-6.02-fix-efi-ovmf.patch
new file mode 100644
index 000000000..f33f4c1de
--- /dev/null
+++ b/libre-testing/syslinux/syslinux-6.02-fix-efi-ovmf.patch
@@ -0,0 +1,621 @@
+The value of the field rva_and_sizes_nr is used by OVMF to check the
+consistency of the PE file with respect to the field optional_hdr_sz. It
+now have the right value.
+
+Signed-off-by: Celelibi <celelibi at gmail.com>
+---
+ efi/wrapper.c | 6 +++---
+ efi/wrapper.h | 28 ++++++++++++++++------------
+ 2 files changed, 19 insertions(+), 15 deletions(-)
+
+diff --git a/efi/wrapper.c b/efi/wrapper.c
+index 04c895f..ec77271 100644
+--- a/efi/wrapper.c
++++ b/efi/wrapper.c
+@@ -102,7 +102,7 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ e_hdr.image_sz = total_sz;
+ e_hdr.headers_sz = 512;
+ e_hdr.subsystem = IMAGE_SUBSYSTEM_EFI_APPLICATION;
+- e_hdr.rva_and_sizes_nr = 1;
++ e_hdr.rva_and_sizes_nr = sizeof(e_hdr.data_directory) / sizeof(__uint64_t);
+ fwrite(&e_hdr, sizeof(e_hdr), 1, f);
+ }
+ else if (class == ELFCLASS64) {
+@@ -130,7 +130,7 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ e_hdr_pe32p.image_sz = total_sz;
+ e_hdr_pe32p.headers_sz = 512;
+ e_hdr_pe32p.subsystem = IMAGE_SUBSYSTEM_EFI_APPLICATION;
+- e_hdr_pe32p.rva_and_sizes_nr = 1;
++ e_hdr_pe32p.rva_and_sizes_nr = sizeof(e_hdr_pe32p.data_directory) / sizeof(__uint64_t);
+ fwrite(&e_hdr_pe32p, sizeof(e_hdr_pe32p), 1, f);
+ }
+
+@@ -237,7 +237,7 @@ int main(int argc, char **argv)
+ fprintf(stderr, "Unsupported architecture\n");
+ exit(EXIT_FAILURE);
+ }
+-
++
+ if (id[EI_MAG0] != ELFMAG0 ||
+ id[EI_MAG1] != ELFMAG1 ||
+ id[EI_MAG2] != ELFMAG2 ||
+diff --git a/efi/wrapper.h b/efi/wrapper.h
+index 4f76991..0e6b38e 100644
+--- a/efi/wrapper.h
++++ b/efi/wrapper.h
+@@ -102,12 +102,14 @@ struct extra_hdr {
+ __uint32_t heap_commit_sz;
+ __uint32_t loader_flags;
+ __uint32_t rva_and_sizes_nr;
+- __uint64_t export_table;
+- __uint64_t import_table;
+- __uint64_t resource_table;
+- __uint64_t exception_table;
+- __uint64_t certification_table;
+- __uint64_t base_relocation_table;
++ struct {
++ __uint64_t export_table;
++ __uint64_t import_table;
++ __uint64_t resource_table;
++ __uint64_t exception_table;
++ __uint64_t certification_table;
++ __uint64_t base_relocation_table;
++ } data_directory;
+ } __packed;
+
+ /* Extra header for PE32+ format
+@@ -136,12 +138,14 @@ struct extra_hdr_pe32p {
+ __uint64_t heap_commit_sz;
+ __uint32_t loader_flags;
+ __uint32_t rva_and_sizes_nr;
+- __uint64_t export_table;
+- __uint64_t import_table;
+- __uint64_t resource_table;
+- __uint64_t exception_table;
+- __uint64_t certification_table;
+- __uint64_t base_relocation_table;
++ struct {
++ __uint64_t export_table;
++ __uint64_t import_table;
++ __uint64_t resource_table;
++ __uint64_t exception_table;
++ __uint64_t certification_table;
++ __uint64_t base_relocation_table;
++ } data_directory;
+ } __packed;
+
+ struct section {
+In the generated PE file, the section header for the .text section used
+to address more than the whole file. Starting at offset 0 (before the
+end of the headers) is illegal and is rejected by OVMF. Giving a size
+greater than the actual file size is also illegal and rejected.
+
+Moreover, the actual data inside the PE file have to be aligned to at
+least 512 bytes. Hence, .text need to be aligned as well.
+
+Signed-off-by: Celelibi <celelibi at gmail.com>
+---
+ efi/wrapper.c | 44 +++++++++++++++++++++++++-------------------
+ 1 file changed, 25 insertions(+), 19 deletions(-)
+
+diff --git a/efi/wrapper.c b/efi/wrapper.c
+index ec77271..bd2c175 100644
+--- a/efi/wrapper.c
++++ b/efi/wrapper.c
+@@ -54,11 +54,15 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ struct coff_hdr c_hdr;
+ struct header hdr;
+ struct coff_reloc c_rel;
+- __uint32_t total_sz = so_size;
++ __uint32_t total_sz = data_size;
+ __uint32_t dummy = 0;
+ __uint32_t hdr_sz;
+ __uint32_t reloc_start, reloc_end;
+
++ hdr_sz = 512;
++ total_sz += hdr_sz;
++ entry += hdr_sz;
++
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.msdos_signature = MSDOS_SIGNATURE;
+
+@@ -77,11 +81,6 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ c_hdr.nr_sections = 2;
+ c_hdr.nr_syms = 1;
+ if (class == ELFCLASS32) {
+- hdr_sz = sizeof(o_hdr) + sizeof(t_sec) + sizeof(e_hdr) +
+- sizeof(r_sec) + sizeof(c_hdr) + sizeof(hdr) + sizeof(c_rel)
+- + sizeof(dummy);
+- total_sz += hdr_sz;
+- entry += hdr_sz;
+ c_hdr.arch = IMAGE_FILE_MACHINE_I386;
+ c_hdr.characteristics = IMAGE_FILE_32BIT_MACHINE |
+ IMAGE_FILE_DEBUG_STRIPPED | IMAGE_FILE_EXECUTABLE_IMAGE |
+@@ -92,25 +91,20 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ o_hdr.format = PE32_FORMAT;
+ o_hdr.major_linker_version = 0x02;
+ o_hdr.minor_linker_version = 0x14;
+- o_hdr.code_sz = total_sz;
++ o_hdr.code_sz = data_size;
+ o_hdr.entry_point = entry;
+ o_hdr.initialized_data_sz = data_size;
+ fwrite(&o_hdr, sizeof(o_hdr), 1, f);
+ memset(&e_hdr, 0, sizeof(e_hdr));
+ e_hdr.section_align = 4096;
+ e_hdr.file_align = 512;
+- e_hdr.image_sz = total_sz;
+- e_hdr.headers_sz = 512;
++ e_hdr.image_sz = hdr_sz + so_size;
++ e_hdr.headers_sz = hdr_sz;
+ e_hdr.subsystem = IMAGE_SUBSYSTEM_EFI_APPLICATION;
+ e_hdr.rva_and_sizes_nr = sizeof(e_hdr.data_directory) / sizeof(__uint64_t);
+ fwrite(&e_hdr, sizeof(e_hdr), 1, f);
+ }
+ else if (class == ELFCLASS64) {
+- hdr_sz = sizeof(o_hdr_pe32p) + sizeof(t_sec) + sizeof(e_hdr_pe32p) +
+- sizeof(r_sec) + sizeof(c_hdr) + sizeof(hdr) + sizeof(c_rel)
+- + sizeof(dummy);
+- total_sz += hdr_sz;
+- entry += hdr_sz;
+ c_hdr.arch = IMAGE_FILE_MACHINE_X86_64;
+ c_hdr.characteristics = IMAGE_FILE_DEBUG_STRIPPED | IMAGE_FILE_EXECUTABLE_IMAGE |
+ IMAGE_FILE_LINE_NUMBERS_STRIPPED;
+@@ -120,15 +114,15 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ o_hdr_pe32p.format = PE32P_FORMAT;
+ o_hdr_pe32p.major_linker_version = 0x02;
+ o_hdr_pe32p.minor_linker_version = 0x14;
+- o_hdr_pe32p.code_sz = total_sz;
++ o_hdr_pe32p.code_sz = data_size;
+ o_hdr_pe32p.entry_point = entry;
+ o_hdr.initialized_data_sz = data_size;
+ fwrite(&o_hdr_pe32p, sizeof(o_hdr_pe32p), 1, f);
+ memset(&e_hdr_pe32p, 0, sizeof(e_hdr));
+ e_hdr_pe32p.section_align = 4096;
+ e_hdr_pe32p.file_align = 512;
+- e_hdr_pe32p.image_sz = total_sz;
+- e_hdr_pe32p.headers_sz = 512;
++ e_hdr_pe32p.image_sz = hdr_sz + so_size;
++ e_hdr_pe32p.headers_sz = hdr_sz;
+ e_hdr_pe32p.subsystem = IMAGE_SUBSYSTEM_EFI_APPLICATION;
+ e_hdr_pe32p.rva_and_sizes_nr = sizeof(e_hdr_pe32p.data_directory) / sizeof(__uint64_t);
+ fwrite(&e_hdr_pe32p, sizeof(e_hdr_pe32p), 1, f);
+@@ -136,8 +130,10 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+
+ memset(&t_sec, 0, sizeof(t_sec));
+ strcpy((char *)t_sec.name, ".text");
+- t_sec.virtual_sz = total_sz;
+- t_sec.raw_data_sz = total_sz;
++ t_sec.virtual_sz = data_size;
++ t_sec.virtual_address = hdr_sz;
++ t_sec.raw_data_sz = t_sec.virtual_sz;
++ t_sec.raw_data = t_sec.virtual_address;
+ t_sec.characteristics = IMAGE_SCN_CNT_CODE |
+ IMAGE_SCN_ALIGN_16BYTES | IMAGE_SCN_MEM_EXECUTE |
+ IMAGE_SCN_MEM_READ;
+@@ -163,6 +159,16 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ fwrite(&c_rel, sizeof(c_rel), 1, f);
+ fwrite(&dummy, sizeof(dummy), 1, f);
+
++ /*
++ * Add some padding to align the ELF as needed
++ */
++ if (ftell(f) > t_sec.virtual_address) {
++ // A fseek that rewind would be a bug hard to track
++ fprintf(stderr, "PE+ headers are too large.\n");
++ exit(EXIT_FAILURE);
++ }
++
++ fseek(f, t_sec.virtual_address, SEEK_SET);
+ }
+
+ static void usage(char *progname)
+There is no need to have a relocation section that nothing points at.
+The image is still seen as relocatable as long as the Characteristics of
+the FileHeader do not say otherwise.
+
+Moreover, the field base_relocation_table wasn't initialized properly
+leading to unpredictable bugs.
+
+Signed-off-by: Celelibi <celelibi at gmail.com>
+---
+
+I'm not 100% positive about the uselessness of the relocation section. However:
+1) it works on my real hardware;
+2) OVMF doesn't check the section headers at all;
+3) all the docs I could find say that the section names are arbitrary;
+4) the only way to make the relocation actually happen is by setting the
+base_relocation_table field of the extra headers to point to this section;
+5) The right way to indicate the image is not relocatable would be by setting
+the characteristics IMAGE_FILE_RELOCS_STRIPPED in the coff header.
+
+Moreover, the relocation entry cannot be inserted before the end of the headers
+(512 bytes), this mean we would have to push everything a few bytes further.
+And I think it's better if it can be avoided. :)
+
+ efi/wrapper.c | 28 +++-------------------------
+ 1 file changed, 3 insertions(+), 25 deletions(-)
+
+diff --git a/efi/wrapper.c b/efi/wrapper.c
+index bd2c175..9652368 100644
+--- a/efi/wrapper.c
++++ b/efi/wrapper.c
+@@ -48,14 +48,12 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ {
+ struct optional_hdr o_hdr;
+ struct optional_hdr_pe32p o_hdr_pe32p;
+- struct section t_sec, r_sec;
++ struct section t_sec;
+ struct extra_hdr e_hdr;
+ struct extra_hdr_pe32p e_hdr_pe32p;
+ struct coff_hdr c_hdr;
+ struct header hdr;
+- struct coff_reloc c_rel;
+ __uint32_t total_sz = data_size;
+- __uint32_t dummy = 0;
+ __uint32_t hdr_sz;
+ __uint32_t reloc_start, reloc_end;
+
+@@ -78,7 +76,7 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ fwrite(&hdr, sizeof(hdr), 1, f);
+
+ memset(&c_hdr, 0, sizeof(c_hdr));
+- c_hdr.nr_sections = 2;
++ c_hdr.nr_sections = 1;
+ c_hdr.nr_syms = 1;
+ if (class == ELFCLASS32) {
+ c_hdr.arch = IMAGE_FILE_MACHINE_I386;
+@@ -118,7 +116,7 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ o_hdr_pe32p.entry_point = entry;
+ o_hdr.initialized_data_sz = data_size;
+ fwrite(&o_hdr_pe32p, sizeof(o_hdr_pe32p), 1, f);
+- memset(&e_hdr_pe32p, 0, sizeof(e_hdr));
++ memset(&e_hdr_pe32p, 0, sizeof(e_hdr_pe32p));
+ e_hdr_pe32p.section_align = 4096;
+ e_hdr_pe32p.file_align = 512;
+ e_hdr_pe32p.image_sz = hdr_sz + so_size;
+@@ -140,26 +138,6 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ fwrite(&t_sec, sizeof(t_sec), 1, f);
+
+ /*
+- * Write our dummy relocation and reloc section.
+- */
+- memset(&r_sec, 0, sizeof(r_sec));
+- strcpy((char *)r_sec.name, ".reloc");
+- r_sec.virtual_sz = sizeof(c_rel);
+- r_sec.virtual_address = ftell(f) + sizeof(r_sec);
+- r_sec.raw_data_sz = r_sec.virtual_sz;
+- r_sec.raw_data = r_sec.virtual_address;
+- r_sec.characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA |
+- IMAGE_SCN_ALIGN_1BYTES | IMAGE_SCN_MEM_DISCARDABLE |
+- IMAGE_SCN_MEM_READ;
+- fwrite(&r_sec, sizeof(r_sec), 1, f);
+-
+- memset(&c_rel, 0, sizeof(c_rel));
+- c_rel.virtual_address = ftell(f) + sizeof(c_rel);
+- c_rel.symtab_index = 10;
+- fwrite(&c_rel, sizeof(c_rel), 1, f);
+- fwrite(&dummy, sizeof(dummy), 1, f);
+-
+- /*
+ * Add some padding to align the ELF as needed
+ */
+ if (ftell(f) > t_sec.virtual_address) {
+PE headers code_sz and image_sz indicate more or less, the size of the
+file and the size of the in-memory image. They are now given the right
+value.
+
+In the ELF format, only the program headers are reliable to determine
+the actually needed part of the file and the in-memory size.
+
+The .bss section should always be marked as NOLOAD for ld since its
+content shouldn't be included into the binary file.
+
+Signed-off-by: Celelibi <celelibi at gmail.com>
+---
+
+Again, I'm not 100% positive about the semantics of NOLOAD in a linker script.
+However I found this make things work better.
+Actually the file core/fs/fs.o have a .bss16 section that is not empty. If I
+understood correctly, only .bss can be empty in a .o. Thus ld generates the
+zeros that belong to that section in the .o. Then, when merging the section
+.bss16 into the .bss of syslinux.so, ld is forced to generate ALL the zeros
+that belong to the .bss section. Marking this section as NOLOAD make ld to
+ignore its content but still produce a PT_LOAD program header with the right
+memory size, as needed for the bss.
+
+ efi/i386/syslinux.ld | 4 +-
+ efi/wrapper.c | 138 +++++++++++++++----------------------------------
+ efi/x86_64/syslinux.ld | 4 +-
+ 3 files changed, 45 insertions(+), 101 deletions(-)
+
+diff --git a/efi/i386/syslinux.ld b/efi/i386/syslinux.ld
+index 523a9b9..bab3fc7 100644
+--- a/efi/i386/syslinux.ld
++++ b/efi/i386/syslinux.ld
+@@ -136,7 +136,7 @@ SECTIONS
+ *(.strtab)
+ }
+
+- .bss : {
++ .bss (NOLOAD) : {
+ /* the EFI loader doesn't seem to like a .bss section,
+ so we stick it all into .data: */
+ __bss_start = .;
+@@ -153,7 +153,7 @@ SECTIONS
+ __bss_dwords = (__bss_len + 3) >> 2;
+
+ . = ALIGN(128);
+-
++
+ /* Very large objects which don't need to be zeroed */
+
+ .hugebss : {
+diff --git a/efi/wrapper.c b/efi/wrapper.c
+index 9652368..a5247ae 100644
+--- a/efi/wrapper.c
++++ b/efi/wrapper.c
+@@ -35,7 +35,7 @@ typedef Elf64_Addr Elf_Addr;
+ #endif
+
+ /*
+- * 'so_size' is the file size of the ELF shared object.
++ * 'so_memsz' is the size of the ELF shared object once loaded.
+ * 'data_size' is the size of initialised data in the shared object.
+ * 'class' dictates how the header is written
+ * For 32bit machines (class == ELFCLASS32), the optional
+@@ -44,7 +44,7 @@ typedef Elf64_Addr Elf_Addr;
+ * header includes PE32+header fields
+ */
+ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+- __uint32_t so_size, __uint8_t class)
++ __uint32_t so_memsz, __uint8_t class)
+ {
+ struct optional_hdr o_hdr;
+ struct optional_hdr_pe32p o_hdr_pe32p;
+@@ -96,7 +96,7 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ memset(&e_hdr, 0, sizeof(e_hdr));
+ e_hdr.section_align = 4096;
+ e_hdr.file_align = 512;
+- e_hdr.image_sz = hdr_sz + so_size;
++ e_hdr.image_sz = hdr_sz + so_memsz;
+ e_hdr.headers_sz = hdr_sz;
+ e_hdr.subsystem = IMAGE_SUBSYSTEM_EFI_APPLICATION;
+ e_hdr.rva_and_sizes_nr = sizeof(e_hdr.data_directory) / sizeof(__uint64_t);
+@@ -119,7 +119,7 @@ static void write_header(FILE *f, __uint32_t entry, size_t data_size,
+ memset(&e_hdr_pe32p, 0, sizeof(e_hdr_pe32p));
+ e_hdr_pe32p.section_align = 4096;
+ e_hdr_pe32p.file_align = 512;
+- e_hdr_pe32p.image_sz = hdr_sz + so_size;
++ e_hdr_pe32p.image_sz = hdr_sz + so_memsz;
+ e_hdr_pe32p.headers_sz = hdr_sz;
+ e_hdr_pe32p.subsystem = IMAGE_SUBSYSTEM_EFI_APPLICATION;
+ e_hdr_pe32p.rva_and_sizes_nr = sizeof(e_hdr_pe32p.data_directory) / sizeof(__uint64_t);
+@@ -157,17 +157,16 @@ static void usage(char *progname)
+
+ int main(int argc, char **argv)
+ {
+- struct stat st;
+ Elf32_Ehdr e32_hdr;
+ Elf64_Ehdr e64_hdr;
+ __uint32_t entry;
+ __uint8_t class;
+- __uint64_t shoff;
+- __uint16_t shnum, shentsize, shstrndx;
++ __uint64_t phoff = 0;
++ __uint16_t phnum = 0, phentsize = 0;
+ unsigned char *id;
+ FILE *f_in, *f_out;
+ void *buf;
+- size_t datasz, rv;
++ size_t datasz, memsz, rv;
+
+ if (argc < 3) {
+ usage(argv[0]);
+@@ -180,11 +179,6 @@ int main(int argc, char **argv)
+ exit(EXIT_FAILURE);
+ }
+
+- if (stat(argv[1], &st) != 0) {
+- perror("stat");
+- exit(EXIT_FAILURE);
+- }
+-
+ f_out = fopen(argv[2], "w");
+ if (!f_out) {
+ perror("fopen");
+@@ -194,15 +188,14 @@ int main(int argc, char **argv)
+ /*
+ * Parse the ELF header and find the entry point.
+ */
+- fread((void *)&e32_hdr, sizeof(e32_hdr), 1, f_in);
++ fread((void *)&e32_hdr, sizeof(e32_hdr), 1, f_in);
+ if (e32_hdr.e_ident[EI_CLASS] == ELFCLASS32) {
+ id = e32_hdr.e_ident;
+ class = ELFCLASS32;
+ entry = e32_hdr.e_entry;
+- shoff = e32_hdr.e_shoff;
+- shnum = e32_hdr.e_shnum;
+- shstrndx = e32_hdr.e_shstrndx;
+- shentsize = e32_hdr.e_shentsize;
++ phoff = e32_hdr.e_phoff;
++ phnum = e32_hdr.e_phnum;
++ phentsize = e32_hdr.e_phentsize;
+ }
+ else if (e32_hdr.e_ident[EI_CLASS] == ELFCLASS64) {
+ /* read the header again for x86_64
+@@ -213,10 +206,9 @@ int main(int argc, char **argv)
+ fread((void *)&e64_hdr, sizeof(e64_hdr), 1, f_in);
+ id = e64_hdr.e_ident;
+ entry = e64_hdr.e_entry;
+- shoff = e64_hdr.e_shoff;
+- shnum = e64_hdr.e_shnum;
+- shstrndx = e64_hdr.e_shstrndx;
+- shentsize = e64_hdr.e_shentsize;
++ phoff = e64_hdr.e_phoff;
++ phnum = e64_hdr.e_phnum;
++ phentsize = e64_hdr.e_phentsize;
+ } else {
+ fprintf(stderr, "Unsupported architecture\n");
+ exit(EXIT_FAILURE);
+@@ -230,98 +222,47 @@ int main(int argc, char **argv)
+ exit(EXIT_FAILURE);
+ }
+
+- if (!shoff || !shnum || (shstrndx == SHN_UNDEF)) {
+- fprintf(stderr, "Cannot find section table\n");
++ if (!phoff || !phnum) {
++ fprintf(stderr, "Cannot find segment table\n");
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+- * Find the beginning of the .bss section. Everything preceding
+- * it is copied verbatim to the output file.
++ * Find the LOAD program header. Everything in this segment
++ * is copied verbatim to the output file.
++ * Although there may be several LOAD program headers, only
++ * one is currently copied.
+ */
+ if (e32_hdr.e_ident[EI_CLASS] == ELFCLASS32) {
+- const char *shstrtab, *name;
+- Elf32_Shdr shdr;
++ Elf32_Phdr phdr;
+ int i;
+- void *strtab;
+-
+- fseek(f_in, shoff, SEEK_SET);
+-
+- /* First find the strtab section */
+- fseek(f_in, shstrndx * shentsize, SEEK_CUR);
+- fread(&shdr, sizeof(shdr), 1, f_in);
+
+- strtab = malloc(shdr.sh_size);
+- if (!strtab) {
+- fprintf(stderr, "Failed to malloc strtab\n");
+- exit(EXIT_FAILURE);
+- }
+-
+- fseek(f_in, shdr.sh_offset, SEEK_SET);
+- fread(strtab, shdr.sh_size, 1, f_in);
+-
+- /* Now search for the .bss section */
+- fseek(f_in, shoff, SEEK_SET);
+- for (i = 0; i < shnum; i++) {
+- rv = fread(&shdr, sizeof(shdr), 1, f_in);
+- if (!rv) {
+- fprintf(stderr, "Failed to read section table\n");
+- exit(EXIT_FAILURE);
+- }
++ /* Find the first LOAD program header */
++ for (i = 0; i < phnum; i++) {
++ fseek(f_in, phoff + i * phentsize, SEEK_SET);
++ fread(&phdr, sizeof(phdr), 1, f_in);
+
+- name = strtab + shdr.sh_name;
+- if (!strcmp(name, ".bss"))
++ if (phdr.p_type == PT_LOAD)
+ break;
+ }
+
+- if (i == shnum) {
+- fprintf(stderr, "Failed to find .bss section\n");
+- exit(EXIT_FAILURE);
+- }
+-
+- datasz = shdr.sh_offset;
+- }
+- else if (e32_hdr.e_ident[EI_CLASS] == ELFCLASS64) {
+- const char *shstrtab, *name;
+- Elf64_Shdr shdr;
++ datasz = phdr.p_filesz;
++ memsz = phdr.p_memsz;
++ } else if (e32_hdr.e_ident[EI_CLASS] == ELFCLASS64) {
++ Elf64_Phdr phdr;
+ int i;
+- void *strtab;
+-
+- fseek(f_in, shoff, SEEK_SET);
+
+- /* First find the strtab section */
+- fseek(f_in, shstrndx * shentsize, SEEK_CUR);
+- fread(&shdr, sizeof(shdr), 1, f_in);
+-
+- strtab = malloc(shdr.sh_size);
+- if (!strtab) {
+- fprintf(stderr, "Failed to malloc strtab\n");
+- exit(EXIT_FAILURE);
+- }
++ /* Find the first LOAD program header */
++ for (i = 0; i < phnum; i++) {
++ fseek(f_in, phoff + i * phentsize, SEEK_SET);
++ fread(&phdr, sizeof(phdr), 1, f_in);
+
+- fseek(f_in, shdr.sh_offset, SEEK_SET);
+- fread(strtab, shdr.sh_size, 1, f_in);
+-
+- /* Now search for the .bss section */
+- fseek(f_in, shoff, SEEK_SET);
+- for (i = 0; i < shnum; i++) {
+- rv = fread(&shdr, sizeof(shdr), 1, f_in);
+- if (!rv) {
+- fprintf(stderr, "Failed to read section table\n");
+- exit(EXIT_FAILURE);
+- }
+-
+- name = strtab + shdr.sh_name;
+- if (!strcmp(name, ".bss"))
++ if (phdr.p_type == PT_LOAD)
+ break;
+ }
+
+- if (i == shnum) {
+- fprintf(stderr, "Failed to find .bss section\n");
+- exit(EXIT_FAILURE);
+- }
+-
+- datasz = shdr.sh_offset;
++ datasz = phdr.p_filesz;
++ memsz = phdr.p_memsz;
+ }
+
+ buf = malloc(datasz);
+@@ -330,7 +271,7 @@ int main(int argc, char **argv)
+ exit(EXIT_FAILURE);
+ }
+
+- write_header(f_out, entry, datasz, st.st_size, class);
++ write_header(f_out, entry, datasz, memsz, class);
+
+ /* Write out the entire ELF shared object */
+ rewind(f_in);
+@@ -341,5 +282,8 @@ int main(int argc, char **argv)
+ }
+
+ fwrite(buf, datasz, rv, f_out);
++ free(buf);
++ fclose(f_out);
++ fclose(f_in);
+ return 0;
+ }
+diff --git a/efi/x86_64/syslinux.ld b/efi/x86_64/syslinux.ld
+index 95160bd..450641c 100644
+--- a/efi/x86_64/syslinux.ld
++++ b/efi/x86_64/syslinux.ld
+@@ -136,7 +136,7 @@ SECTIONS
+ *(.strtab)
+ }
+
+- .bss : {
++ .bss (NOLOAD) : {
+ /* the EFI loader doesn't seem to like a .bss section,
+ so we stick it all into .data: */
+ __bss_start = .;
+@@ -153,7 +153,7 @@ SECTIONS
+ __bss_dwords = (__bss_len + 3) >> 2;
+
+ . = ALIGN(128);
+-
++
+ /* Very large objects which don't need to be zeroed */
+
+ .hugebss : {