diff options
| -rwxr-xr-x | masm/a.out | bin | 0 -> 4848 bytes | |||
| -rw-r--r-- | masm/asm.c | 34 | ||||
| -rw-r--r-- | masm/asm.h | 1 | ||||
| -rw-r--r-- | masm/out.o | bin | 0 -> 4632 bytes | |||
| -rw-r--r-- | masm/test.asm | 5 |
5 files changed, 33 insertions, 7 deletions
diff --git a/masm/a.out b/masm/a.out Binary files differnew file mode 100755 index 0000000..0a4bfee --- /dev/null +++ b/masm/a.out @@ -17,6 +17,8 @@ extern char *current_file; #define SYMSEC_STUB -1 #define SYMSEC_EXTERN -1 +#define SEC_ALIGN 0x1000 + static int create_symbol(struct assembler *assembler, const char name[MAX_LEX_LENGTH], ssize_t section_idx, @@ -338,7 +340,7 @@ static int assemble_phdr(struct assembler *assembler, Elf32_Phdr **res, hdr->p_paddr = 0; hdr->p_filesz = htonl(size); hdr->p_memsz = htonl(size); - hdr->p_align = htonl(0x1000); + hdr->p_align = htonl(SEC_ALIGN); } *res = phdr; @@ -530,17 +532,30 @@ static void update_offsets(struct assembler *assembler, Elf32_Ehdr *ehdr) ptr += len * sizeof(Elf32_Rela); } + // section padding + { + uint32_t mod = ptr % SEC_ALIGN; + if (mod != 0) + assembler->secalign = (SEC_ALIGN - mod); + else + assembler->secalign = 0; + ptr += assembler->secalign; + } + // sections + size_t v_addr = 0x00400000; for (uint32_t i = 0; i < assembler->sectab.len; i++) { struct section *sec = &assembler->sectab.sections[i]; - int idx = sec->shdr_idx; + uint32_t idx = sec->shdr_idx; + uint32_t size = ntohl(phdr[i].p_filesz); phdr[i].p_offset = htonl(ptr); - phdr[i].p_vaddr = htonl(ptr); - phdr[i].p_paddr = htonl(ptr); + phdr[i].p_vaddr = htonl(v_addr); + phdr[i].p_paddr = htonl(v_addr); shdr[idx].sh_offset = htonl(ptr); shdr[idx].sh_size = phdr[i].p_filesz; shdr[idx].sh_addr = phdr[i].p_vaddr; - ptr += ntohl(phdr[i].p_filesz); + v_addr += size; + ptr += size; } // symtab @@ -567,8 +582,7 @@ static void update_offsets(struct assembler *assembler, Elf32_Ehdr *ehdr) static void update_sym_shindx(struct assembler *assembler) { - for (size_t i = 0; i < assembler->symtab.len; i++) - { + for (size_t i = 0; i < assembler->symtab.len; i++) { Elf32_Sym *sym = &assembler->symtab.symbols[i]; ssize_t sec = assembler->symtab.sections[i]; @@ -605,6 +619,12 @@ static int write_file(struct assembler *assembler, Elf32_Ehdr *ehdr, fwrite(ptr, sizeof(Elf32_Rela), len, out); } + // section padding + for (uint32_t i = 0; i < assembler->secalign; i++) { + uint8_t zero = 0; + fwrite(&zero, 1, 1, out); + } + // sections for (uint32_t i = 0; i < assembler->sectab.len; i++) { struct section *sec = &assembler->sectab.sections[i]; @@ -213,6 +213,7 @@ struct assembler { /// Segments struct section_table sectab; + uint32_t secalign; // align sections to 0x1000 when writing /// program header Elf32_Phdr *phdr; diff --git a/masm/out.o b/masm/out.o Binary files differnew file mode 100644 index 0000000..0b697af --- /dev/null +++ b/masm/out.o diff --git a/masm/test.asm b/masm/test.asm index b4c1498..d848d29 100644 --- a/masm/test.asm +++ b/masm/test.asm @@ -1,3 +1,8 @@ +.rodata +gay: +.word 3 + + .data str: |