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- /*
- * $Source$
- * $State$
- *
- * Simple tool to produce an utterly basic ELF executable
- * from an absolute ack.out file. Suitable for operating
- * systems like Linux.
- *
- * This tool produces an executable with a program header
- * only and no section header.
- *
- * Mostly pinched from the ARM cv (and then rewritten in
- * ANSI C). Which, according to the comment, was pinched
- * from m68k2; therefore I am merely continuing a time-
- * honoured tradition.
- *
- * (I was 10 when the original for this was checked into
- * CVS...)
- *
- * dtrg, 2006-10-17
- */
- #include <stdlib.h>
- #include <stdio.h>
- #include <stdarg.h>
- #include <stdint.h>
- #include <string.h>
- #include "out.h"
- #define ASSERT(x) switch (2) { case 0: case (x): ; }
- /* Global settings. */
- int bigendian = 0;
- int elfmachine;
- /* Header and section table of an ack object file. */
-
- struct outhead outhead;
- struct outsect outsect[S_MAX];
- char* stringarea;
- char* outputfile = NULL; /* Name of output file, or NULL */
- char* program; /* Name of current program: argv[0] */
- FILE* input; /* Input stream */
- FILE* output; /* Output stream */
- #define readf(a, b, c) fread((a), (b), (int)(c), input)
- #define writef(a, b, c) fwrite((a), (b), (int)(c), output)
- /* Header and program header table of an ELF object file. */
- #define ELF_HEADER_SIZE 0x34
- #define PROGRAM_HEADER_SIZE 0x20
- #define PROGRAM_HEADER_COUNT 1
- unsigned long codeoffset;
- const char elf_le_ident_string[] = {
- 0x7F, 'E', 'L', 'F'
- };
- /* Output file definitions and such */
- #define HDR_LENGTH 32
- char hdr[HDR_LENGTH] ;
- /* Segment numbers understood by aslod. */
- enum {
- TEXT = 0,
- ROM,
- DATA,
- BSS,
- NUM_SEGMENTS
- };
- #define N_EXT 040
- #define N_UNDEF 00
- #define N_ABS 01
- #define N_TEXT 02
- #define N_DATA 03
- #define N_BSS 04
- #define N_FN 037
- /* Produce an error message and exit. */
- void fatal(const char* s, ...)
- {
- va_list ap;
-
- fprintf(stderr, "%s: ",program) ;
-
- va_start(ap, s);
- vfprintf(stderr, s, ap);
- va_end(ap);
-
- fprintf(stderr, "\n");
-
- if (outputfile)
- unlink(outputfile);
- exit(1);
- }
- /* Calculate the result of a aligned to b (rounding up if necessary).
- * b must be a power of two. */
- long align(long a, long b)
- {
- a += b - 1;
- return a & ~(b-1);
- }
-
- int follows(struct outsect* pa, struct outsect* pb)
- {
- /* return 1 if pa follows pb */
-
- return (pa->os_base == align(pb->os_base+pb->os_size, pa->os_lign));
- }
- /* Writes a byte. */
- void emit8(unsigned char value)
- {
- writef(&value, 1, 1);
- }
- /* Writes out 16 and 32 bit words in the appropriate endianness. */
- void emit16(unsigned short value)
- {
- unsigned char buffer[2];
-
- if (bigendian)
- {
- buffer[0] = (value >> 8) & 0xFF;
- buffer[1] = (value >> 0) & 0xFF;
- }
- else
- {
- buffer[1] = (value >> 8) & 0xFF;
- buffer[0] = (value >> 0) & 0xFF;
- }
-
- writef(buffer, 1, sizeof(buffer));
- }
- void emit32(unsigned long value)
- {
- unsigned char buffer[4];
-
- if (bigendian)
- {
- buffer[0] = (value >> 24) & 0xFF;
- buffer[1] = (value >> 16) & 0xFF;
- buffer[2] = (value >> 8) & 0xFF;
- buffer[3] = (value >> 0) & 0xFF;
- }
- else
- {
- buffer[3] = (value >> 24) & 0xFF;
- buffer[2] = (value >> 16) & 0xFF;
- buffer[1] = (value >> 8) & 0xFF;
- buffer[0] = (value >> 0) & 0xFF;
- }
-
- writef(buffer, 1, sizeof(buffer));
- }
-
- /* Copies the contents of a section from the input stream
- * to the output stream. */
-
- void emits(struct outsect* section)
- {
- char buffer[BUFSIZ];
- long n = section->os_flen;
- while (n > 0)
- {
- int blocksize = (n > BUFSIZ) ? BUFSIZ : n;
- readf(buffer, 1, blocksize);
- writef(buffer, 1, blocksize);
- n -= blocksize;
- }
- /* Zero fill any remaining space. */
-
- if (section->os_flen != section->os_size)
- {
- long n = section->os_size - section->os_flen;
- memset(buffer, 0, BUFSIZ);
- while (n > 0)
- {
- int blocksize = (n > BUFSIZ) ? BUFSIZ : n;
- writef(buffer, 1, blocksize);
- n -= blocksize;
- }
- }
- }
- /* Writes out an ELF program header. */
- void emitphdr(unsigned long address, unsigned long filesize,
- unsigned int memsize, unsigned int alignment, int flags)
- {
- static unsigned long fileoffset = 0;
-
- emit32(1); /* type = PT_LOAD */
- emit32(fileoffset); /* file offset */
- emit32(address); /* virtual address */
- emit32(0); /* physical address */
- emit32(filesize); /* file size */
- emit32(memsize); /* memory size */
- emit32(flags); /* executable, readable, writable */
- emit32(alignment); /* alignment */
-
- fileoffset += filesize;
- }
- void iconvert(char* buf, char* str, char* fmt)
- {
- register char *nf, *ni, *no ;
- int last, i ;
- uint32_t value ;
- ni=buf ; no=str ; nf=fmt ;
- while (( last = *nf++ )) {
- last -= '0' ;
- if ( last<1 || last >9 ) fatal("illegal out.h format string\n");
- value=0 ;
- i=last ;
- while ( i-- ) {
- value = (value<<8) + (ni[i]&0xFF) ;
- }
- switch ( last ) {
- case 0 : break ;
- case 1 : *no= value ; break ;
- case 2 : *(uint16_t *)no = value ; break ;
- case 4 : *(uint32_t *)no = value ; break ;
- default :
- fatal("illegal out.h format string\n");
- }
- ni += last ; no += last ;
- }
- }
- /* Read the ack.out file header. */
- int rhead(FILE* f, struct outhead* head)
- {
- char buf[sizeof(struct outhead)];
-
- if (fread(buf, sizeof(buf), 1, f) != 1)
- return 0;
-
- iconvert(buf, (char*) head, SF_HEAD);
- return 1;
- }
- /* Read an ack.out section header. */
-
- int rsect(FILE* f, struct outsect* sect)
- {
- char buf[sizeof(struct outsect)];
-
- if (fread(buf, sizeof(buf), 1, f) != 1)
- return 0;
-
- iconvert(buf, (char*) sect, SF_SECT);
- return 1 ;
- }
- int main(int argc, char* argv[])
- {
- /* General housecleaning and setup. */
-
- input = stdin;
- output = stdout;
- program = argv[0];
-
- /* Read in and process any flags. */
-
- while ((argc > 1) && (argv[1][0] == '-'))
- {
- switch (argv[1][1])
- {
- case 'h':
- fprintf(stderr, "%s: Syntax: aslod [-h] <inputfile> <outputfile>\n",
- program);
- exit(0);
-
- default:
- syntaxerror:
- fatal("syntax error --- try -h for help)");
- }
-
- argv++;
- argc--;
- }
- /* Process the rest of the arguments. */
-
- switch (argc)
- {
- case 1: /* No parameters --- read from stdin, write to stdout. */
- break;
-
- case 3: /* Both input and output files specified. */
- output = fopen(argv[2], "w");
- if (!output)
- fatal("unable to open output file.");
- outputfile = argv[2];
- /* fall through */
-
- case 2: /* Input file specified. */
- input = fopen(argv[1], "r");
- if (!input)
- fatal("unable to open input file.");
- break;
-
- default:
- goto syntaxerror;
- }
- /* Read and check the ack.out file header. */
-
- if (!rhead(input,&outhead))
- fatal("failed to read file header.");
- if (BADMAGIC(outhead))
- fatal("this isn't an ack object file.");
- if (outhead.oh_nrelo > 0)
- fprintf(stderr, "Warning: relocation information present.");
- if (!((outhead.oh_nsect == NUM_SEGMENTS) ||
- (outhead.oh_nsect == (NUM_SEGMENTS+1))))
- fatal("the input file must have %d sections, not %ld.",
- NUM_SEGMENTS, outhead.oh_nsect);
-
- /* Read in the section headers. */
-
- {
- int i;
- for (i=0; i<outhead.oh_nsect; i++)
- {
- if (!rsect(input, &outsect[i]))
- fatal("failed to read section header %d.", i);
- }
- }
- /* A few checks */
- if (outsect[BSS].os_flen != 0)
- fatal("the bss space contains initialized data.");
- if (!follows(&outsect[BSS], &outsect[DATA]))
- fatal("the bss segment must follow the data segment.");
- if (!follows(& outsect[ROM], &outsect[TEXT]))
- fatal("the rom segment must follow the text segment.");
- if (!follows(&outsect[DATA], &outsect[ROM]))
- fatal("the data segment must follow the rom segment.") ;
- /* Check for an optional end segment (which is otherwise
- * ignored). */
-
- if (outhead.oh_nsect == (NUM_SEGMENTS+1))
- {
- if (!follows(&outsect[NUM_SEGMENTS], &outsect[BSS]))
- fatal("end segment must follow bss");
- if ( outsect[NUM_SEGMENTS].os_size != 0 )
- fatal("end segment must be empty");
- }
- /* Ensure the base address doesn't overlap the file header. */
- codeoffset = outsect[TEXT].os_base & 0x1FFF;
- if (codeoffset < (ELF_HEADER_SIZE + PROGRAM_HEADER_SIZE*PROGRAM_HEADER_COUNT))
- fatal("base address too small --- overlaps ELF header");
- /* Rationalise the memory sizes. */
-
- outsect[TEXT].os_size = outsect[ROM ].os_base - outsect[TEXT].os_base;
- outsect[ROM ].os_size = outsect[DATA].os_base - outsect[ROM ].os_base;
- outsect[DATA].os_size = outsect[BSS ].os_base - outsect[DATA].os_base;
- outsect[BSS ].os_size = align(outsect[BSS].os_size, outsect[BSS].os_lign);
- /* Write out the ELF file header. */
-
- writef(elf_le_ident_string, 4, 1);
- emit8(1); /* class = ELFCLASS32 */
- emit8(bigendian ? 2 : 1); /* endianness */
- emit8(1); /* ELF version */
- emit8(3); /* ABI = Linux */
- emit8(0); /* ABI version */
- emit8(0); emit16(0); /* padding... */
- emit32(0); /* ...to offset 0x10 */
-
- emit16(2); /* type = ET_EXEC */
- emit16(3); /* machine = EM_386 */
- emit32(1); /* ELF version again */
- emit32(outsect[TEXT].os_base); /* entry point */
- emit32(ELF_HEADER_SIZE); /* program header offset */
- emit32(0); /* section header offset */
- emit32(0); /* flags */
- emit16(ELF_HEADER_SIZE); /* elf header size */
- emit16(PROGRAM_HEADER_SIZE); /* program header entry size */
- emit16(1); /* number of program header entries */
- emit16(0); /* section header entry size */
- emit16(0); /* number of section header entries */
- emit16(0); /* section header string table index = SHN_UNDEF */
-
- /* Write out a single rwx section for the entire program. */
-
- {
- unsigned long filelength = codeoffset +
- outsect[TEXT].os_size +
- outsect[ROM].os_size +
- outsect[DATA].os_size;
-
- unsigned long memlength = filelength +
- outsect[BSS].os_size;
-
- emitphdr(outsect[TEXT].os_base & ~0x1FFF, filelength, memlength,
- 0, 4|2|1);
- }
- /* Write padding until the code start. */
-
- fseek(output, codeoffset, SEEK_SET);
- /* Write out the actual data. */
-
- emits(&outsect[TEXT]);
- emits(&outsect[ROM]);
- emits(&outsect[DATA]);
- if (ferror(output))
- fatal("output write error");
- if (outputfile)
- chmod(outputfile, 0755);
- /* Summarise what we've done. */
-
- {
- long ss = 0;
- printf(" address length\n");
- printf(" ehdr : %08lX %08lX\n", outsect[TEXT].os_base & ~0x1FFF, codeoffset);
- printf(" text : %08lX %08lX\n", outsect[TEXT].os_base, outsect[TEXT].os_size);
- printf(" rom : %08lX %08lX\n", outsect[ROM].os_base, outsect[ROM].os_size);
- printf(" data : %08lX %08lX\n", outsect[DATA].os_base, outsect[DATA].os_size);
- printf(" bss : %08lX %08lX\n", outsect[BSS].os_base, outsect[BSS].os_size);
- ss += outsect[TEXT].os_size;
- ss += outsect[ROM].os_size;
- ss += outsect[DATA].os_size;
- ss += outsect[BSS].os_size;
- printf("TOTAL : %08lX\n", ss);
- }
-
- return 0;
- }
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