load.c

eCos操作系统源码

//==========================================================================
//
//      load.c
//
//      RedBoot file/image loader
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
// Copyright (C) 2002, 2003, 2004 Gary Thomas
//
// eCos is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// As a special exception, if other files instantiate templates or use macros
// or inline functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
// This exception does not invalidate any other reasons why a work based on
// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    gthomas
// Contributors: gthomas, tsmith
// Date:         2000-07-14
// Purpose:      
// Description:  
//              
// This code is part of RedBoot (tm).
//
//####DESCRIPTIONEND####
//
//==========================================================================

#include <redboot.h>
#include <elf.h>
#ifdef CYGBLD_BUILD_REDBOOT_WITH_XYZMODEM
#include <xyzModem.h>
#endif
#ifdef CYGPKG_REDBOOT_DISK
#include <fs/disk.h>
#endif
#ifdef CYGPKG_REDBOOT_FILEIO
#include <fs/fileio.h>
#endif
#ifdef CYGPKG_REDBOOT_NETWORKING
#ifdef CYGSEM_REDBOOT_NET_TFTP_DOWNLOAD
#include <net/tftp_support.h>
#endif
#ifdef CYGSEM_REDBOOT_NET_HTTP_DOWNLOAD
#include <net/http.h>
#endif
#endif
#include <cyg/infra/cyg_ass.h>         // assertion macros

static char usage[] = "[-r] [-v] "
#ifdef CYGBLD_BUILD_REDBOOT_WITH_ZLIB
                      "[-d] "
#endif
#ifdef CYGPKG_REDBOOT_NETWORKING
                      "[-h <host>] [-p <TCP port>]"
#endif
                      "[-m <varies>] "
#if CYGNUM_HAL_VIRTUAL_VECTOR_NUM_CHANNELS > 1
                      "[-c <channel_number>] "
#endif
                      "\n        [-b <base_address>] <file_name>";

// Exported CLI function
RedBoot_cmd("load", 
            "Load a file", 
            usage,
            do_load 
    );

//
// Stream I/O support
//

// Table describing the various I/O methods
CYG_HAL_TABLE_BEGIN( __RedBoot_LOAD_TAB__, RedBoot_load );
CYG_HAL_TABLE_END( __RedBoot_LOAD_TAB_END__, RedBoot_load );
extern struct load_io_entry __RedBoot_LOAD_TAB__[], __RedBoot_LOAD_TAB_END__;

// Buffers, data used by redboot_getc
#define BUF_SIZE 256
struct {
    getc_io_funcs_t *io;
    int (*fun)(char *, int len, int *err);
    unsigned char  buf[BUF_SIZE];
    unsigned char *bufp;
    int   avail, len, err;
    int   verbose, decompress, tick;
#ifdef CYGBLD_BUILD_REDBOOT_WITH_ZLIB
    int (*raw_fun)(char *, int len, int *err);
    _pipe_t load_pipe;
    unsigned char _buffer[CYGNUM_REDBOOT_LOAD_ZLIB_BUFFER];
#endif
} getc_info;

typedef int (*getc_t)(void);

//
// Read the next data byte from the stream.
// Returns:
//    >= 0 - actual data
//      -1 - error or EOF, status in getc_info.err
//
static int 
redboot_getc(void)
{
    static char spin[] = "|/-\\|-";
    if (getc_info.avail < 0) {
      return -1;
    }
    if (getc_info.avail == 0) {
        if (getc_info.verbose) {
            diag_printf("%c\b", spin[getc_info.tick++]);
            if (getc_info.tick >= sizeof(spin)) {
                getc_info.tick = 0;
            }
        }
        if (getc_info.len < BUF_SIZE) {
            // No more data available
            if (getc_info.verbose) diag_printf("\n");
            return -1;
        }
        getc_info.bufp = getc_info.buf;
        getc_info.len = (*getc_info.fun)(getc_info.bufp, BUF_SIZE, &getc_info.err);
        if ((getc_info.avail = getc_info.len) <= 0) {
            if (getc_info.len < 0) {
                diag_printf("I/O error: %s\n", (getc_info.io->error)(getc_info.err));
            }
            if (getc_info.verbose) diag_printf("\n");
            return -1;
        }
    }
    getc_info.avail--;
    return *getc_info.bufp++;
}

#ifdef CYGBLD_BUILD_REDBOOT_WITH_ZLIB
//
// Called to fetch a new chunk of data and decompress it
//
static int 
_decompress_stream(char *buf, int len, int *err)
{
    _pipe_t* p = &getc_info.load_pipe;
    int res, total;

    total = 0;
    while (len > 0) {
        if (p->in_avail == 0) {
            p->in_buf = &getc_info._buffer[0];
            res = (*getc_info.raw_fun)(p->in_buf, CYGNUM_REDBOOT_LOAD_ZLIB_BUFFER, 
                                       &getc_info.err);
            if ((p->in_avail = res) <= 0) {
                // No more data
                return total;
            }
        }
        p->out_buf = buf;
        p->out_size = 0;
        p->out_max = len;
        res = (*_dc_inflate)(p);
        if (res != 0) {
            *err = res;
            return total;
        }        
        len -= p->out_size;
        buf += p->out_size;
        total += p->out_size;
    }
    return total;
}
#endif

static int
redboot_getc_init(connection_info_t *info, getc_io_funcs_t *funcs, 
                  int verbose, int decompress)
{
    int res;

    res = (funcs->open)(info, &getc_info.err);    
    if (res < 0) {
        diag_printf("Can't load '%s': %s\n", info->filename, (funcs->error)(getc_info.err));
            return res;
    }
    getc_info.io = funcs;
    getc_info.fun = funcs->read;
    getc_info.avail = 0;
    getc_info.len = BUF_SIZE;
    getc_info.verbose = verbose;
    getc_info.decompress = decompress;
    getc_info.tick = 0;
#ifdef CYGBLD_BUILD_REDBOOT_WITH_ZLIB
    if (decompress) {
        _pipe_t* p = &getc_info.load_pipe;
        p->out_buf = &getc_info.buf[0];
        p->out_size = 0;
        p->in_avail = 0;
        getc_info.raw_fun = getc_info.fun;
        getc_info.fun = _decompress_stream;
        getc_info.err = (*_dc_init)(p);
        if (0 != getc_info.err && p->msg) {
            diag_printf("open decompression error: %s\n", p->msg);
        }
    }
#endif
    return 0;
}

static void
redboot_getc_rewind(void)
{
    getc_info.bufp = getc_info.buf;
    getc_info.avail = getc_info.len;
}

static void
redboot_getc_terminate(bool abort)
{
    if (getc_info.io->terminate) {
        (getc_info.io->terminate)(abort, redboot_getc);
    }
}

static void
redboot_getc_close(void)
{
    (getc_info.io->close)(&getc_info.err);
#ifdef CYGBLD_BUILD_REDBOOT_WITH_ZLIB
    if (getc_info.decompress) {
        _pipe_t* p = &getc_info.load_pipe;
        int err = getc_info.err;
        if (0 != err && p->msg) {
            diag_printf("decompression error: %s\n", p->msg);
        }
        err = (*_dc_close)(p, getc_info.err);
    }
#endif
}

#ifdef CYGSEM_REDBOOT_ELF
//
// Support function - used to read bytes into a buffer
// Returns the number of bytes read (stops short on errors)
//
static int
_read(int (*getc)(void), unsigned char *buf, int len)
{
    int total = 0;
    int ch;
    while (len-- > 0) {
        ch = (*getc)();
        if (ch < 0) {
            // EOF or error
            break;
        }
        *buf++ = ch;
        total++;
    }
    return total;
}
#endif

//
// Load an ELF [binary] image 
//
static unsigned long
load_elf_image(getc_t getc, unsigned long base)
{
#ifdef CYGSEM_REDBOOT_ELF
    Elf32_Ehdr ehdr;
#define MAX_PHDR 8
    Elf32_Phdr phdr[MAX_PHDR];
    unsigned long offset = 0;
    int phx, len, ch;
    unsigned char *addr;
    unsigned long addr_offset = 0;
    unsigned long highest_address = 0;
    unsigned long lowest_address = 0xFFFFFFFF;
    unsigned char *SHORT_DATA = "Short data reading ELF file\n";

    // Read the header
    if (_read(getc, (unsigned char *)&ehdr, sizeof(ehdr)) != sizeof(ehdr)) {
        diag_printf("Can't read ELF header\n");
        return 0;
    }
    offset += sizeof(ehdr);    
#if 0 // DEBUG
    diag_printf("Type: %d, Machine: %d, Version: %d, Entry: %p, PHoff: %p/%d/%d, SHoff: %p/%d/%d\n",
                ehdr.e_type, ehdr.e_machine, ehdr.e_version, ehdr.e_entry, 
                ehdr.e_phoff, ehdr.e_phentsize, ehdr.e_phnum,
                ehdr.e_shoff, ehdr.e_shentsize, ehdr.e_shnum);
#endif
    if (ehdr.e_type != ET_EXEC) {
        diag_printf("Only absolute ELF images supported\n");
        return 0;
    }
    if (ehdr.e_phnum > MAX_PHDR) {
        diag_printf("Too many program headers\n");
        return 0;
    }
    while (offset < ehdr.e_phoff) {
        if ((*getc)() < 0) {
            diag_printf(SHORT_DATA);
            return 0;
        }
        offset++;
    }
    for (phx = 0;  phx < ehdr.e_phnum;  phx++) {
        if (_read(getc, (unsigned char *)&phdr[phx], sizeof(phdr[0])) != sizeof(phdr[0])) {
            diag_printf("Can't read ELF program header\n");
            return 0;
        }
#if 0 // DEBUG
        diag_printf("Program header: type: %d, off: %p, va: %p, pa: %p, len: %d/%d, flags: %d\n",
                    phdr[phx].p_type, phdr[phx].p_offset, phdr[phx].p_vaddr, phdr[phx].p_paddr,
                    phdr[phx].p_filesz, phdr[phx].p_memsz, phdr[phx].p_flags);
#endif
        offset += sizeof(phdr[0]);
    }
    if (base) {
        // Set address offset based on lowest address in file.
        addr_offset = 0xFFFFFFFF;
        for (phx = 0;  phx < ehdr.e_phnum;  phx++) {    
            if ((phdr[phx].p_type == PT_LOAD) && (phdr[phx].p_paddr < addr_offset)) {
                addr_offset = phdr[phx].p_paddr;
            }
        }
        addr_offset = (unsigned long)base - addr_offset;
    } else {
        addr_offset = 0;
    }
    for (phx = 0;  phx < ehdr.e_phnum;  phx++) {
        if (phdr[phx].p_type == PT_LOAD) {
            // Loadable segment
            addr = (unsigned char *)phdr[phx].p_paddr;
            len = phdr[phx].p_filesz;
            if ((unsigned long)addr < lowest_address) {
                lowest_address = (unsigned long)addr;
            }
            addr += addr_offset;
            if (offset > phdr[phx].p_offset) {
                if ((phdr[phx].p_offset + len) < offset) {
                    diag_printf("Can't load ELF file - program headers out of order\n");
                    return 0;
                }
                addr += offset - phdr[phx].p_offset;
            } else {
                while (offset < phdr[phx].p_offset) {
                    if ((*getc)() < 0) {
                        diag_printf(SHORT_DATA);
                        return 0;
                    }
                    offset++;
                }
            }
            // Copy data into memory
            while (len-- > 0) {
#ifdef CYGSEM_REDBOOT_VALIDATE_USER_RAM_LOADS
                if (!valid_address(addr)) {
                    redboot_getc_terminate(true);
                    diag_printf("*** Abort! Attempt to load ELF data to address: %p which is not in RAM\n", (void*)addr);
                    return 0;
                }
#endif
                if ((ch = (*getc)()) < 0) {
                    diag_printf(SHORT_DATA);
                    return 0;
                }
                *addr++ = ch;
                offset++;
                if ((unsigned long)(addr-addr_offset) > highest_address) {
                    highest_address = (unsigned long)(addr - addr_offset);
                }
            }
        }
    }
    // Save load base/top and entry
    if (base) {
        load_address = base;