Refactor into monorepo

1 files changed, 204 insertions, 0 deletions

diff --git a/elf/src/main.c b/elf/src/main.c
new file mode 100644
index 0000000..8a79586
--- /dev/null
+++ b/elf/src/main.c
@@ -0,0 +1,204 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <lcq/elf.h>
+
+u8 TEST_PROG[] = {
+    0x48, 0xc7, 0xc0, 0x3c, 0x00, 0x00, 0x00, /* mov $0x3c,%rax */
+    0x48, 0xc7, 0xc7, 0x2a, 0x00, 0x00, 0x00, /* mov $0x2a,%rdi */
+    0x0f, 0x05 /* syscall */
+};
+
+int main(int argc, char **argv) {
+    elf_ctx e = {0};
+    elf_header h = {0};
+    elf_section_header sh = {0};
+    elf_program_header ph = {0};
+    i64 i = 0;
+
+    if (argc < 3) { fprintf(stderr, "usage: %s MODE ELF-PATH\n", argv[0]); return 1; }
+    if (strcmp(argv[1], "read") == 0) {
+        e = elf_load_from_path(argv[2]);
+        elf_read_header(&h, &e);
+        printf("%d %d %d %d %d\n", e.ident.file_class, e.ident.endianness, e.ident.version, e.ident.abi, e.ident.abi_version);
+        printf("type=%u, machine=%u\n", h.type, h.machine);
+        printf("version=%u, entry=0x%lx\n", h.version, h.entry);
+        printf("ph=%lu, sh=%lu\n", h.program_header_offset, h.section_header_offset);
+        printf("flags=%u, eh=%u\n", h.flags, h.elf_header_size);
+        printf("ph_ent_size=%u, ph_ents=%u\n", h.program_header_entry_size, h.program_header_entries);
+        printf("sh_ent_size=%u, sh_ents=%u\n", h.section_header_entry_size, h.section_header_entries);
+        printf("nametable=%u\n", h.section_name_table_index);
+
+        for (i = 0; i < h.section_header_entries; ++i) {
+            char *name = NULL;
+            elf_read_section_header(&sh, &e, elf_section_header_offset(&h, (u64) i));
+            name = elf_read_section_name(&e, &h, &sh);
+            printf("section %ld (%s) type: %u\n", i, name, sh.type);
+        }
+        for (i = 0; i < h.section_header_entries; ++i) {
+            elf_read_section_header(&sh, &e, elf_section_header_offset(&h, (u64) i));
+            if (sh.type == ELF_SECTION_TYPE_SYMTAB) {
+                u64 symoff = 0;
+                for (symoff = 0; symoff < sh.size; symoff += sh.entry_size) {
+                    elf_symbol s = {0};
+                    elf_read_symbol(&s, &e, sh.offset + symoff);
+                    printf("symbol offset %ld (%s) type: %u\n",
+                        symoff,
+                        elf_read_symbol_name(&e, &h, &sh, &s),
+                        s.type
+                    );
+                }
+            }
+        }
+    } else {
+        elf_symbol s = {0};
+        i64 len = 1024 * 16;
+        u8 *buf = calloc((size_t) len, sizeof(u8));
+        FILE *f = NULL;
+        u64 sh_off = 0,
+            shstrtab_off = 0,
+            shstrtab_name_off = 0,
+            shstrtab_len = 0,
+            strtab_off = 0,
+            strtab_name_off = 0,
+            strtab_len = 0,
+            symtab_off = 0,
+            symtab_name_off = 0,
+            symtab_len = 0,
+            text_off = 0,
+            text_name_off = 0,
+            text_len = 0,
+            program_header_off = 0,
+            off = 0,
+            symbols = 0,
+            sections = 0;
+        e = elf_ctx_new(buf, len, ELF_CLASS_64, ELF_ENDIANNESS_LITTLE);
+        off = ELF64_HEADER_SIZE;
+
+        /* make space for program header */
+        program_header_off = off;
+        off += ELF64_PROGRAM_HEADER_SIZE;
+
+        /* write shstrtab */
+        shstrtab_off = off;
+        e.buf[off++] = 0;
+        shstrtab_name_off = off - shstrtab_off; elf_write_bytes(&e, &off, ELF_STRTAB_BYTES_OFF(".shstrtab"));
+        strtab_name_off = off - shstrtab_off; elf_write_bytes(&e, &off, ELF_STRTAB_BYTES_OFF(".strtab"));
+        symtab_name_off = off - shstrtab_off; elf_write_bytes(&e, &off, ELF_STRTAB_BYTES_OFF(".symtab"));
+        text_name_off = off - shstrtab_off; elf_write_bytes(&e, &off, ELF_STRTAB_BYTES_OFF(".text"));
+        e.buf[off++] = 0;
+        shstrtab_len = off - shstrtab_off;
+
+        /* write strtab */
+        strtab_off = off;
+        e.buf[off++] = 0;
+        elf_write_bytes(&e, &off, ELF_STRTAB_BYTES_OFF("_start"));
+        e.buf[off++] = 0;
+        strtab_len = off - strtab_off;
+
+        /* write symtab */
+        symtab_off = off;
+        printf("symtab_off: %lu\n", symtab_off);
+        /* null symbol */
+        symbols += 1;
+        s.size = 0;
+        s.value = 0;
+        s.name_index = 0;
+        s.bind = ELF_SYMBOL_BINDING_LOCAL;
+        s.type = ELF_SYMBOL_TYPE_NOTYPE;
+        s.visibility = ELF_SYMBOL_VISIBILITY_DEFAULT;
+        s.section_header_index = 0;
+        elf_write_symbol(&s, &e, off);
+        off += ELF64_SYMBOL_SIZE;
+
+        /* _start */
+        symbols += 1;
+        s.size = 0;
+        s.value = 0x401000;
+        s.name_index = 1;
+        s.bind = ELF_SYMBOL_BINDING_GLOBAL;
+        s.type = ELF_SYMBOL_TYPE_NOTYPE;
+        s.visibility = ELF_SYMBOL_VISIBILITY_DEFAULT;
+        s.section_header_index = 4;
+        elf_write_symbol(&s, &e, off);
+        off += ELF64_SYMBOL_SIZE;
+        symtab_len = off - symtab_off;
+
+        /* write text */
+        /* text_off = off; */
+        text_off = 0x1000;
+        text_len = text_off;
+        elf_write_bytes(&e, &text_len, TEST_PROG, sizeof(TEST_PROG));
+        /* text_len = off - text_off; */
+        text_len -= text_off;
+
+        /* write section headers */
+        sh_off = off;
+
+        /* null section */
+        sections += 1;
+        sh.name_index = 0; sh.type = ELF_SECTION_TYPE_NULL;
+        sh.flags = 0; sh.addr = 0; sh.offset = 0; sh.size = 0;
+        sh.link = 0; sh.info = 0; sh.addr_alignment = 0; sh.entry_size = 0;
+        elf_write_section_header(&sh, &e, off); off += ELF64_SECTION_HEADER_SIZE;
+
+        /* .shstrtab */
+        sections += 1;
+        sh.name_index = (u32) shstrtab_name_off; sh.type = ELF_SECTION_TYPE_STRTAB;
+        sh.flags = 0; sh.addr = 0; sh.offset = shstrtab_off; sh.size = shstrtab_len;
+        sh.link = 0; sh.info = 0; sh.addr_alignment = 0; sh.entry_size = 0;
+        elf_write_section_header(&sh, &e, off); off += ELF64_SECTION_HEADER_SIZE;
+
+        /* .strtab */
+        sections += 1;
+        sh.name_index = (u32) strtab_name_off; sh.type = ELF_SECTION_TYPE_STRTAB;
+        sh.flags = 0; sh.addr = 0; sh.offset = strtab_off; sh.size = strtab_len;
+        sh.link = 0; sh.info = 0; sh.addr_alignment = 0; sh.entry_size = 0;
+        elf_write_section_header(&sh, &e, off); off += ELF64_SECTION_HEADER_SIZE;
+
+        /* .symtab */
+        sections += 1;
+        sh.name_index = (u32) symtab_name_off; sh.type = ELF_SECTION_TYPE_SYMTAB;
+        sh.flags = 0; sh.addr = 0; sh.offset = symtab_off; sh.size = symtab_len;
+        sh.link = 2; sh.info = 1; sh.addr_alignment = 0; sh.entry_size = ELF64_SYMBOL_SIZE;
+        elf_write_section_header(&sh, &e, off); off += ELF64_SECTION_HEADER_SIZE;
+
+        /* .text */
+        sections += 1;
+        sh.name_index = (u32) text_name_off; sh.type = ELF_SECTION_TYPE_PROGBITS;
+        sh.flags = ELF_SECTION_FLAG_ALLOC | ELF_SECTION_FLAG_EXECINSTR;
+        sh.addr = 0x401000; sh.offset = text_off; sh.size = text_len;
+        sh.link = 0; sh.info = 0; sh.addr_alignment = 0; sh.entry_size = 0;
+        elf_write_section_header(&sh, &e, off); off += ELF64_SECTION_HEADER_SIZE;
+
+        /* write program header */
+        ph.type = ELF_PROGRAM_HEADER_TYPE_LOAD;
+        ph.offset = text_off;
+        ph.virtual_addr = 0x401000;
+        ph.physical_addr = 0;
+        ph.file_size = (u32) text_len;
+        ph.mem_size = (u32) text_len;
+        ph.flags = ELF_PROGRAM_HEADER_FLAG_R | ELF_PROGRAM_HEADER_FLAG_X;
+        ph.align = 0;
+        elf_write_program_header(&ph, &e, program_header_off);
+
+        /* write header at the start */
+        h.type = ELF_TYPE_EXEC;
+        h.machine = ELF_MACHINE_AMD64;
+        h.version = 1;
+        h.entry = 0x401000;
+        h.program_header_offset = program_header_off;
+        h.program_header_entry_size = ELF64_PROGRAM_HEADER_SIZE;
+        h.program_header_entries = 1;
+        h.section_header_offset = sh_off;
+        h.section_header_entry_size = ELF64_SECTION_HEADER_SIZE;
+        h.section_header_entries = (u16) sections;
+        h.section_name_table_index = 1;
+        elf_write_header(&h, &e);
+        f = fopen(argv[2], "w+");
+        fwrite(buf, sizeof(u8), (size_t) len, f);
+        fclose(f);
+    }
+    return 0;
+}