tramp.c

Go to the documentation of this file.

/*
 * tramp.c
 *
 * DSP-BIOS Bridge driver support functions for TI OMAP processors.
 *
 * Copyright (C) 2009 Texas Instruments, Inc.
 *
 * This package is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include "header.h"

#if TMS32060
#include "tramp_table_c6000.c"
#endif

#define MAX_RELOS_PER_PASS  4

/*
 * Function:    priv_tramp_sect_tgt_alloc
 * Description: Allocate target memory for the trampoline section.  The
 *    target mem size is easily obtained as the next available address.
 */
static int priv_tramp_sect_tgt_alloc(struct dload_state *dlthis)
{
    int ret_val = 0;
    struct ldr_section_info *sect_info;

    /*  Populate the trampoline loader section and allocate it on the
     * target.  The section name is ALWAYS the first string in the final
     * string table for trampolines.  The trampoline section is always
     * 1 beyond the total number of allocated sections. */
    sect_info = &dlthis->ldr_sections[dlthis->allocated_secn_count];

    sect_info->name = dlthis->tramp.final_string_table;
    sect_info->size = dlthis->tramp.tramp_sect_next_addr;
    sect_info->context = 0;
    sect_info->type =
        (4 << 8) | DLOAD_TEXT | DS_ALLOCATE_MASK | DS_DOWNLOAD_MASK;
    sect_info->page = 0;
    sect_info->run_addr = 0;
    sect_info->load_addr = 0;
    ret_val = dlthis->myalloc->dload_allocate(dlthis->myalloc,
                          sect_info,
                          ds_alignment
                          (sect_info->type));

    if (ret_val == 0)
        dload_error(dlthis, "Failed to allocate target memory for"
                " trampoline");

    return ret_val;
}

/*
 * Function:    priv_h2a
 * Description: Helper function to convert a hex value to its ASCII
 *    representation.  Used for trampoline symbol name generation.
 */
static u8 priv_h2a(u8 value)
{
    if (value > 0xF)
        return 0xFF;

    if (value <= 9)
        value += 0x30;
    else
        value += 0x37;

    return value;
}

/*
 * Function:    priv_tramp_sym_gen_name
 * Description: Generate a trampoline symbol name (ASCII) using the value
 *    of the symbol.  This places the new name into the user buffer.
 *    The name is fixed in length and of the form: __$dbTR__xxxxxxxx
 *    (where "xxxxxxxx" is the hex value).
 */
static void priv_tramp_sym_gen_name(u32 value, char *dst)
{
    u32 i;
    char *prefix = TRAMP_SYM_PREFIX;
    char *dst_local = dst;
    u8 tmp;

    /*  Clear out the destination, including the ending NULL */
    for (i = 0; i < (TRAMP_SYM_PREFIX_LEN + TRAMP_SYM_HEX_ASCII_LEN); i++)
        *(dst_local + i) = 0;

    /*  Copy the prefix to start */
    for (i = 0; i < strlen(TRAMP_SYM_PREFIX); i++) {
        *dst_local = *(prefix + i);
        dst_local++;
    }

    /*  Now convert the value passed in to a string equiv of the hex */
    for (i = 0; i < sizeof(value); i++) {
#ifndef _BIG_ENDIAN
        tmp = *(((u8 *) &value) + (sizeof(value) - 1) - i);
        *dst_local = priv_h2a((tmp & 0xF0) >> 4);
        dst_local++;
        *dst_local = priv_h2a(tmp & 0x0F);
        dst_local++;
#else
        tmp = *(((u8 *) &value) + i);
        *dst_local = priv_h2a((tmp & 0xF0) >> 4);
        dst_local++;
        *dst_local = priv_h2a(tmp & 0x0F);
        dst_local++;
#endif
    }

    /*  NULL terminate */
    *dst_local = 0;
}

/*
 * Function:    priv_tramp_string_create
 * Description: Create a new string specific to the trampoline loading and add
 *    it to the trampoline string list.  This list contains the
 *    trampoline section name and trampoline point symbols.
 */
static struct tramp_string *priv_tramp_string_create(struct dload_state *dlthis,
                             u32 str_len, char *str)
{
    struct tramp_string *new_string = NULL;
    u32 i;

    /*  Create a new string object with the specified size. */
    new_string =
        (struct tramp_string *)dlthis->mysym->dload_allocate(dlthis->mysym,
                                 (sizeof
                                  (struct
                                   tramp_string)
                                  + str_len +
                                  1));
    if (new_string != NULL) {
        /*  Clear the string first.  This ensures the ending NULL is
         * present and the optimizer won't touch it. */
        for (i = 0; i < (sizeof(struct tramp_string) + str_len + 1);
             i++)
            *((u8 *) new_string + i) = 0;

        /*  Add this string to our virtual table by assigning it the
         * next index and pushing it to the tail of the list. */
        new_string->index = dlthis->tramp.tramp_string_next_index;
        dlthis->tramp.tramp_string_next_index++;
        dlthis->tramp.tramp_string_size += str_len + 1;

        new_string->next = NULL;
        if (dlthis->tramp.string_head == NULL)
            dlthis->tramp.string_head = new_string;
        else
            dlthis->tramp.string_tail->next = new_string;

        dlthis->tramp.string_tail = new_string;

        /*  Copy the string over to the new object */
        for (i = 0; i < str_len; i++)
            new_string->str[i] = str[i];
    }

    return new_string;
}

/*
 * Function:    priv_tramp_string_find
 * Description: Walk the trampoline string list and find a match for the
 *    provided string.  If not match is found, NULL is returned.
 */
static struct tramp_string *priv_tramp_string_find(struct dload_state *dlthis,
                           char *str)
{
    struct tramp_string *cur_str = NULL;
    struct tramp_string *ret_val = NULL;
    u32 i;
    u32 str_len = strlen(str);

    for (cur_str = dlthis->tramp.string_head;
         (ret_val == NULL) && (cur_str != NULL); cur_str = cur_str->next) {
        /*  If the string lengths aren't equal, don't bother
         * comparing */
        if (str_len != strlen(cur_str->str))
            continue;

        /*  Walk the strings until one of them ends */
        for (i = 0; i < str_len; i++) {
            /*  If they don't match in the current position then
             * break out now, no sense in continuing to look at
             * this string. */
            if (str[i] != cur_str->str[i])
                break;
        }

        if (i == str_len)
            ret_val = cur_str;
    }

    return ret_val;
}

/*
 * Function:    priv_string_tbl_finalize
 * Description: Flatten the trampoline string list into a table of NULL
 *    terminated strings.  This is the same format of string table
 *    as used by the COFF/DOFF file.
 */
static int priv_string_tbl_finalize(struct dload_state *dlthis)
{
    int ret_val = 0;
    struct tramp_string *cur_string;
    char *cur_loc;
    char *tmp;

    /*  Allocate enough space for all strings that have been created.  The
     * table is simply all strings concatenated together will NULL
     * endings. */
    dlthis->tramp.final_string_table =
        (char *)dlthis->mysym->dload_allocate(dlthis->mysym,
                          dlthis->tramp.
                          tramp_string_size);
    if (dlthis->tramp.final_string_table != NULL) {
        /*  We got our buffer, walk the list and release the nodes as*
         * we go */
        cur_loc = dlthis->tramp.final_string_table;
        cur_string = dlthis->tramp.string_head;
        while (cur_string != NULL) {
            /*  Move the head/tail pointers */
            dlthis->tramp.string_head = cur_string->next;
            if (dlthis->tramp.string_tail == cur_string)
                dlthis->tramp.string_tail = NULL;

            /*  Copy the string contents */
            for (tmp = cur_string->str;
                 *tmp != '\0'; tmp++, cur_loc++)
                *cur_loc = *tmp;

            /*  Pick up the NULL termination since it was missed by
             * breaking using it to end the above loop. */
            *cur_loc = '\0';
            cur_loc++;

            /*  Free the string node, we don't need it any more. */
            dlthis->mysym->dload_deallocate(dlthis->mysym,
                            cur_string);

            /*  Move our pointer to the next one */
            cur_string = dlthis->tramp.string_head;
        }

        /*  Update our return value to success */
        ret_val = 1;
    } else
        dload_error(dlthis, "Failed to allocate trampoline "
                "string table");

    return ret_val;
}

/*
 * Function:    priv_tramp_sect_alloc
 * Description: Virtually allocate space from the trampoline section.  This
 *    function returns the next offset within the trampoline section
 *    that is available and moved the next available offset by the
 *    requested size.  NO TARGET ALLOCATION IS DONE AT THIS TIME.
 */
static u32 priv_tramp_sect_alloc(struct dload_state *dlthis, u32 tramp_size)
{
    u32 ret_val;

    /*  If the next available address is 0, this is our first allocation.
     * Create a section name string to go into the string table . */
    if (dlthis->tramp.tramp_sect_next_addr == 0) {
        dload_syms_error(dlthis->mysym, "*** WARNING ***  created "
                 "dynamic TRAMPOLINE section for module %s",
                 dlthis->str_head);
    }

    /*  Reserve space for the new trampoline */
    ret_val = dlthis->tramp.tramp_sect_next_addr;
    dlthis->tramp.tramp_sect_next_addr += tramp_size;
    return ret_val;
}

/*
 * Function:    priv_tramp_sym_create
 * Description: Allocate and create a new trampoline specific symbol and add
 *    it to the trampoline symbol list.  These symbols will include
 *    trampoline points as well as the external symbols they
 *    reference.
 */
static struct tramp_sym *priv_tramp_sym_create(struct dload_state *dlthis,
                           u32 str_index,
                           struct local_symbol *tmp_sym)
{
    struct tramp_sym *new_sym = NULL;
    u32 i;

    /*  Allocate new space for the symbol in the symbol table. */
    new_sym =
        (struct tramp_sym *)dlthis->mysym->dload_allocate(dlthis->mysym,
                          sizeof(struct tramp_sym));
    if (new_sym != NULL) {
        for (i = 0; i != sizeof(struct tramp_sym); i++)
            *((char *)new_sym + i) = 0;

        /*  Assign this symbol the next symbol index for easier
         * reference later during relocation. */
        new_sym->index = dlthis->tramp.tramp_sym_next_index;
        dlthis->tramp.tramp_sym_next_index++;

        /*  Populate the symbol information.  At this point any
         * trampoline symbols will be the offset location, not the
         * final.  Copy over the symbol info to start, then be sure to
         * get the string index from the trampoline string table. */
        new_sym->sym_info = *tmp_sym;
        new_sym->str_index = str_index;

        /*  Push the new symbol to the tail of the symbol table list */
        new_sym->next = NULL;
        if (dlthis->tramp.symbol_head == NULL)
            dlthis->tramp.symbol_head = new_sym;
        else
            dlthis->tramp.symbol_tail->next = new_sym;

        dlthis->tramp.symbol_tail = new_sym;
    }

    return new_sym;
}

/*
 * Function:    priv_tramp_sym_get
 * Description: Search for the symbol with the matching string index (from
 *    the trampoline string table) and return the trampoline
 *    symbol object, if found.  Otherwise return NULL.
 */
static struct tramp_sym *priv_tramp_sym_get(struct dload_state *dlthis,
                        u32 string_index)
{
    struct tramp_sym *sym_found = NULL;

    /*  Walk the symbol table list and search vs. the string index */
    for (sym_found = dlthis->tramp.symbol_head;
         sym_found != NULL; sym_found = sym_found->next) {
        if (sym_found->str_index == string_index)
            break;
    }

    return sym_found;
}

/*
 * Function:    priv_tramp_sym_find
 * Description: Search for a trampoline symbol based on the string name of
 *    the symbol.  Return the symbol object, if found, otherwise
 *    return NULL.
 */
static struct tramp_sym *priv_tramp_sym_find(struct dload_state *dlthis,
                         char *string)
{
    struct tramp_sym *sym_found = NULL;
    struct tramp_string *str_found = NULL;

    /*  First, search for the string, then search for the sym based on the
       string index. */
    str_found = priv_tramp_string_find(dlthis, string);
    if (str_found != NULL)
        sym_found = priv_tramp_sym_get(dlthis, str_found->index);

    return sym_found;
}

/*
 * Function:    priv_tramp_sym_finalize
 * Description: Allocate a flat symbol table for the trampoline section,
 *    put each trampoline symbol into the table, adjust the
 *    symbol value based on the section address on the target and
 *    free the trampoline symbol list nodes.
 */
static int priv_tramp_sym_finalize(struct dload_state *dlthis)
{
    int ret_val = 0;
    struct tramp_sym *cur_sym;
    struct ldr_section_info *tramp_sect =
        &dlthis->ldr_sections[dlthis->allocated_secn_count];
    struct local_symbol *new_sym;

    /*  Allocate a table to hold a flattened version of all symbols
     * created. */
    dlthis->tramp.final_sym_table =
        (struct local_symbol *)dlthis->mysym->dload_allocate(dlthis->mysym,
                 (sizeof(struct local_symbol) * dlthis->tramp.
                          tramp_sym_next_index));
    if (dlthis->tramp.final_sym_table != NULL) {
        /*  Walk the list of all symbols, copy it over to the flattened
         * table. After it has been copied, the node can be freed as
         * it is no longer needed. */
        new_sym = dlthis->tramp.final_sym_table;
        cur_sym = dlthis->tramp.symbol_head;
        while (cur_sym != NULL) {
            /*  Pop it off the list */
            dlthis->tramp.symbol_head = cur_sym->next;
            if (cur_sym == dlthis->tramp.symbol_tail)
                dlthis->tramp.symbol_tail = NULL;

            /*  Copy the symbol contents into the flat table */
            *new_sym = cur_sym->sym_info;

            /*  Now finalize the symbol.  If it is in the tramp
             * section, we need to adjust for the section start.
             * If it is external then we don't need to adjust at
             * all.
             * NOTE: THIS CODE ASSUMES THAT THE TRAMPOLINE IS
             * REFERENCED LIKE A CALL TO AN EXTERNAL SO VALUE AND
             * DELTA ARE THE SAME.  SEE THE FUNCTION dload_symbols
             * WHERE DN_UNDEF IS HANDLED FOR MORE REFERENCE. */
            if (new_sym->secnn < 0) {
                new_sym->value += tramp_sect->load_addr;
                new_sym->delta = new_sym->value;
            }

            /*  Let go of the symbol node */
            dlthis->mysym->dload_deallocate(dlthis->mysym, cur_sym);

            /*  Move to the next node */
            cur_sym = dlthis->tramp.symbol_head;
            new_sym++;
        }

        ret_val = 1;
    } else
        dload_error(dlthis, "Failed to alloc trampoline sym table");

    return ret_val;
}

/*
 * Function:    priv_tgt_img_gen
 * Description: Allocate storage for and copy the target specific image data
 *  and fix up its relocations for the new external symbol.  If
 *  a trampoline image packet was successfully created it is added
 *  to the trampoline list.
 */
static int priv_tgt_img_gen(struct dload_state *dlthis, u32 base,
                u32 gen_index, struct tramp_sym *new_ext_sym)
{
    struct tramp_img_pkt *new_img_pkt = NULL;
    u32 i;
    u32 pkt_size = tramp_img_pkt_size_get();
    u8 *gen_tbl_entry;
    u8 *pkt_data;
    struct reloc_record_t *cur_relo;
    int ret_val = 0;

    /*  Allocate a new image packet and set it up. */
    new_img_pkt =
        (struct tramp_img_pkt *)dlthis->mysym->dload_allocate(dlthis->mysym,
                                  pkt_size);
    if (new_img_pkt != NULL) {
        /*  Save the base, this is where it goes in the section */
        new_img_pkt->base = base;

        /*  Copy over the image data and relos from the target table */
        pkt_data = (u8 *) &new_img_pkt->hdr;
        gen_tbl_entry = (u8 *) &tramp_gen_info[gen_index];
        for (i = 0; i < pkt_size; i++) {
            *pkt_data = *gen_tbl_entry;
            pkt_data++;
            gen_tbl_entry++;
        }

        /*  Update the relocations to point to the external symbol */
        cur_relo =
            (struct reloc_record_t *)((u8 *) &new_img_pkt->hdr +
                          new_img_pkt->hdr.relo_offset);
        for (i = 0; i < new_img_pkt->hdr.num_relos; i++)
            cur_relo[i].SYMNDX = new_ext_sym->index;

        /*  Add it to the trampoline list. */
        new_img_pkt->next = dlthis->tramp.tramp_pkts;
        dlthis->tramp.tramp_pkts = new_img_pkt;

        ret_val = 1;
    }

    return ret_val;
}

/*
 * Function:    priv_pkt_relo
 * Description: Take the provided image data and the collection of relocations
 *    for it and perform the relocations.  Note that all relocations
 *    at this stage are considered SECOND PASS since the original
 *    image has already been processed in the first pass.  This means
 *    TRAMPOLINES ARE TREATED AS 2ND PASS even though this is really
 *    the first (and only) relocation that will be performed on them.
 */
static int priv_pkt_relo(struct dload_state *dlthis, tgt_au_t * data,
             struct reloc_record_t *rp[], u32 relo_count)
{
    int ret_val = 1;
    u32 i;
    bool tmp;

    /*  Walk through all of the relos and process them.  This function is
     * the equivalent of relocate_packet() from cload.c, but specialized
     * for trampolines and 2nd phase relocations. */
    for (i = 0; i < relo_count; i++)
        dload_relocate(dlthis, data, rp[i], &tmp, true);

    return ret_val;
}

/*
 * Function:    priv_tramp_pkt_finalize
 * Description: Walk the list of all trampoline packets and finalize them.
 *    Each trampoline image packet will be relocated now that the
 *    trampoline section has been allocated on the target.  Once
 *    all of the relocations are done the trampoline image data
 *    is written into target memory and the trampoline packet
 *    is freed: it is no longer needed after this point.
 */
static int priv_tramp_pkt_finalize(struct dload_state *dlthis)
{
    int ret_val = 1;
    struct tramp_img_pkt *cur_pkt = NULL;
    struct reloc_record_t *relos[MAX_RELOS_PER_PASS];
    u32 relos_done;
    u32 i;
    struct reloc_record_t *cur_relo;
    struct ldr_section_info *sect_info =
        &dlthis->ldr_sections[dlthis->allocated_secn_count];

    /*  Walk the list of trampoline packets and relocate each packet.  This
     * function is the trampoline equivalent of dload_data() from
     * cload.c. */
    cur_pkt = dlthis->tramp.tramp_pkts;
    while ((ret_val != 0) && (cur_pkt != NULL)) {
        /*  Remove the pkt from the list */
        dlthis->tramp.tramp_pkts = cur_pkt->next;

        /*  Setup section and image offset information for the relo */
        dlthis->image_secn = sect_info;
        dlthis->image_offset = cur_pkt->base;
        dlthis->delta_runaddr = sect_info->run_addr;

        /*  Walk through all relos for the packet */
        relos_done = 0;
        cur_relo = (struct reloc_record_t *)((u8 *) &cur_pkt->hdr +
                             cur_pkt->hdr.relo_offset);
        while (relos_done < cur_pkt->hdr.num_relos) {
#ifdef ENABLE_TRAMP_DEBUG
            dload_syms_error(dlthis->mysym,
                     "===> Trampoline %x branches to %x",
                     sect_info->run_addr +
                     dlthis->image_offset,
                     dlthis->
                     tramp.final_sym_table[cur_relo->
                                   SYMNDX].value);
#endif

            for (i = 0;
                 ((i < MAX_RELOS_PER_PASS) &&
                  ((i + relos_done) < cur_pkt->hdr.num_relos)); i++)
                relos[i] = cur_relo + i;

            /*  Do the actual relo */
            ret_val = priv_pkt_relo(dlthis,
                        (tgt_au_t *) &cur_pkt->payload,
                        relos, i);
            if (ret_val == 0) {
                dload_error(dlthis,
                        "Relocation of trampoline pkt at %x"
                        " failed", cur_pkt->base +
                        sect_info->run_addr);
                break;
            }

            relos_done += i;
            cur_relo += i;
        }

        /*  Make sure we didn't hit a problem */
        if (ret_val != 0) {
            /*  Relos are done for the packet, write it to the
             * target */
            ret_val = dlthis->myio->writemem(dlthis->myio,
                             &cur_pkt->payload,
                             sect_info->load_addr +
                             cur_pkt->base,
                             sect_info,
                             BYTE_TO_HOST
                             (cur_pkt->hdr.
                              tramp_code_size));
            if (ret_val == 0) {
                dload_error(dlthis,
                        "Write to " FMT_UI32 " failed",
                        sect_info->load_addr +
                        cur_pkt->base);
            }

            /*  Done with the pkt, let it go */
            dlthis->mysym->dload_deallocate(dlthis->mysym, cur_pkt);

            /*  Get the next packet to process */
            cur_pkt = dlthis->tramp.tramp_pkts;
        }
    }

    return ret_val;
}

/*
 * Function:    priv_dup_pkt_finalize
 * Description: Walk the list of duplicate image packets and finalize them.
 *    Each duplicate packet will be relocated again for the
 *    relocations that previously failed and have been adjusted
 *    to point at a trampoline.  Once all relocations for a packet
 *    have been done, write the packet into target memory.  The
 *    duplicate packet and its relocation chain are all freed
 *    after use here as they are no longer needed after this.
 */
static int priv_dup_pkt_finalize(struct dload_state *dlthis)
{
    int ret_val = 1;
    struct tramp_img_dup_pkt *cur_pkt;
    struct tramp_img_dup_relo *cur_relo;
    struct reloc_record_t *relos[MAX_RELOS_PER_PASS];
    struct doff_scnhdr_t *sect_hdr = NULL;
    s32 i;

    /* Similar to the trampoline pkt finalize, this function walks each dup
     * pkt that was generated and performs all relocations that were
     * deferred to a 2nd pass.  This is the equivalent of dload_data() from
     * cload.c, but does not need the additional reorder and checksum
     * processing as it has already been done. */
    cur_pkt = dlthis->tramp.dup_pkts;
    while ((ret_val != 0) && (cur_pkt != NULL)) {
        /*  Remove the node from the list, we'll be freeing it
         * shortly */
        dlthis->tramp.dup_pkts = cur_pkt->next;

        /*  Setup the section and image offset for relocation */
        dlthis->image_secn = &dlthis->ldr_sections[cur_pkt->secnn];
        dlthis->image_offset = cur_pkt->offset;

        /*  In order to get the delta run address, we need to reference
         * the original section header.  It's a bit ugly, but needed
         * for relo. */
        i = (s32) (dlthis->image_secn - dlthis->ldr_sections);
        sect_hdr = dlthis->sect_hdrs + i;
        dlthis->delta_runaddr = sect_hdr->ds_paddr;

        /*  Walk all relos in the chain and process each. */
        cur_relo = cur_pkt->relo_chain;
        while (cur_relo != NULL) {
            /*  Process them a chunk at a time to be efficient */
            for (i = 0; (i < MAX_RELOS_PER_PASS)
                 && (cur_relo != NULL);
                 i++, cur_relo = cur_relo->next) {
                relos[i] = &cur_relo->relo;
                cur_pkt->relo_chain = cur_relo->next;
            }

            /*  Do the actual relo */
            ret_val = priv_pkt_relo(dlthis,
                        cur_pkt->img_pkt.img_data,
                        relos, i);
            if (ret_val == 0) {
                dload_error(dlthis,
                        "Relocation of dup pkt at %x"
                        " failed", cur_pkt->offset +
                        dlthis->image_secn->run_addr);
                break;
            }

            /*  Release all of these relos, we're done with them */
            while (i > 0) {
                dlthis->mysym->dload_deallocate(dlthis->mysym,
                        GET_CONTAINER
                        (relos[i - 1],
                         struct tramp_img_dup_relo,
                         relo));
                i--;
            }

            /*  DO NOT ADVANCE cur_relo, IT IS ALREADY READY TO
             * GO! */
        }

        /* Done with all relos.  Make sure we didn't have a problem and
         * write it out to the target */
        if (ret_val != 0) {
            ret_val = dlthis->myio->writemem(dlthis->myio,
                             cur_pkt->img_pkt.
                             img_data,
                             dlthis->image_secn->
                             load_addr +
                             cur_pkt->offset,
                             dlthis->image_secn,
                             BYTE_TO_HOST
                             (cur_pkt->img_pkt.
                              packet_size));
            if (ret_val == 0) {
                dload_error(dlthis,
                        "Write to " FMT_UI32 " failed",
                        dlthis->image_secn->load_addr +
                        cur_pkt->offset);
            }

            dlthis->mysym->dload_deallocate(dlthis->mysym, cur_pkt);

            /*  Advance to the next packet */
            cur_pkt = dlthis->tramp.dup_pkts;
        }
    }

    return ret_val;
}

/*
 * Function:    priv_dup_find
 * Description: Walk the list of existing duplicate packets and find a
 *    match based on the section number and image offset.  Return
 *    the duplicate packet if found, otherwise NULL.
 */
static struct tramp_img_dup_pkt *priv_dup_find(struct dload_state *dlthis,
                           s16 secnn, u32 image_offset)
{
    struct tramp_img_dup_pkt *cur_pkt = NULL;

    for (cur_pkt = dlthis->tramp.dup_pkts;
         cur_pkt != NULL; cur_pkt = cur_pkt->next) {
        if ((cur_pkt->secnn == secnn) &&
            (cur_pkt->offset == image_offset)) {
            /*  Found a match, break out */
            break;
        }
    }

    return cur_pkt;
}

/*
 * Function:    priv_img_pkt_dup
 * Description: Duplicate the original image packet.  If this is the first
 *    time this image packet has been seen (based on section number
 *    and image offset), create a new duplicate packet and add it
 *    to the dup packet list.  If not, just get the existing one and
 *    update it with the current packet contents (since relocation
 *    on the packet is still ongoing in first pass.)  Create a
 *    duplicate of the provided relocation, but update it to point
 *    to the new trampoline symbol.  Add the new relocation dup to
 *    the dup packet's relo chain for 2nd pass relocation later.
 */
static int priv_img_pkt_dup(struct dload_state *dlthis,
                s16 secnn, u32 image_offset,
                struct image_packet_t *ipacket,
                struct reloc_record_t *rp,
                struct tramp_sym *new_tramp_sym)
{
    struct tramp_img_dup_pkt *dup_pkt = NULL;
    u32 new_dup_size;
    s32 i;
    int ret_val = 0;
    struct tramp_img_dup_relo *dup_relo = NULL;

    /*  Determine if this image packet is already being tracked in the
       dup list for other trampolines. */
    dup_pkt = priv_dup_find(dlthis, secnn, image_offset);

    if (dup_pkt == NULL) {
        /*  This image packet does not exist in our tracking, so create
         * a new one and add it to the head of the list. */
        new_dup_size = sizeof(struct tramp_img_dup_pkt) +
            ipacket->packet_size;

        dup_pkt = (struct tramp_img_dup_pkt *)
            dlthis->mysym->dload_allocate(dlthis->mysym, new_dup_size);
        if (dup_pkt != NULL) {
            /*  Save off the section and offset information */
            dup_pkt->secnn = secnn;
            dup_pkt->offset = image_offset;
            dup_pkt->relo_chain = NULL;

            /*  Copy the original packet content */
            dup_pkt->img_pkt = *ipacket;
            dup_pkt->img_pkt.img_data = (u8 *) (dup_pkt + 1);
            for (i = 0; i < ipacket->packet_size; i++)
                *(dup_pkt->img_pkt.img_data + i) =
                    *(ipacket->img_data + i);

            /*  Add the packet to the dup list */
            dup_pkt->next = dlthis->tramp.dup_pkts;
            dlthis->tramp.dup_pkts = dup_pkt;
        } else
            dload_error(dlthis, "Failed to create dup packet!");
    } else {
        /*  The image packet contents could have changed since
         * trampoline detection happens during relocation of the image
         * packets.  So, we need to update the image packet contents
         * before adding relo information. */
        for (i = 0; i < dup_pkt->img_pkt.packet_size; i++)
            *(dup_pkt->img_pkt.img_data + i) =
                *(ipacket->img_data + i);
    }

    /*  Since the previous code may have allocated a new dup packet for us,
       double check that we actually have one. */
    if (dup_pkt != NULL) {
        /*  Allocate a new node for the relo chain.  Each image packet
         * can potentially have multiple relocations that cause a
         * trampoline to be generated.  So, we keep them in a chain,
         * order is not important. */
        dup_relo = dlthis->mysym->dload_allocate(dlthis->mysym,
                     sizeof(struct tramp_img_dup_relo));
        if (dup_relo != NULL) {
            /*  Copy the relo contents, adjust for the new
             * trampoline and add it to the list. */
            dup_relo->relo = *rp;
            dup_relo->relo.SYMNDX = new_tramp_sym->index;

            dup_relo->next = dup_pkt->relo_chain;
            dup_pkt->relo_chain = dup_relo;

            /*  That's it, we're done.  Make sure we update our
             * return value to be success since everything finished
             * ok */
            ret_val = 1;
        } else
            dload_error(dlthis, "Unable to alloc dup relo");
    }

    return ret_val;
}

/*
 * Function:    dload_tramp_avail
 * Description: Check to see if the target supports a trampoline for this type
 *    of relocation.  Return true if it does, otherwise false.
 */
bool dload_tramp_avail(struct dload_state *dlthis, struct reloc_record_t *rp)
{
    bool ret_val = false;
    u16 map_index;
    u16 gen_index;

    /*  Check type hash vs. target tramp table */
    map_index = HASH_FUNC(rp->TYPE);
    gen_index = tramp_map[map_index];
    if (gen_index != TRAMP_NO_GEN_AVAIL)
        ret_val = true;

    return ret_val;
}

/*
 * Function:    dload_tramp_generate
 * Description: Create a new trampoline for the provided image packet and
 *    relocation causing problems.  This will create the trampoline
 *    as well as duplicate/update the image packet and relocation
 *    causing the problem, which will be relo'd again during
 *    finalization.
 */
int dload_tramp_generate(struct dload_state *dlthis, s16 secnn,
             u32 image_offset, struct image_packet_t *ipacket,
             struct reloc_record_t *rp)
{
    u16 map_index;
    u16 gen_index;
    int ret_val = 1;
    char tramp_sym_str[TRAMP_SYM_PREFIX_LEN + TRAMP_SYM_HEX_ASCII_LEN];
    struct local_symbol *ref_sym;
    struct tramp_sym *new_tramp_sym;
    struct tramp_sym *new_ext_sym;
    struct tramp_string *new_tramp_str;
    u32 new_tramp_base;
    struct local_symbol tmp_sym;
    struct local_symbol ext_tmp_sym;

    /*  Hash the relo type to get our generator information */
    map_index = HASH_FUNC(rp->TYPE);
    gen_index = tramp_map[map_index];
    if (gen_index != TRAMP_NO_GEN_AVAIL) {
        /*  If this is the first trampoline, create the section name in
         * our string table for debug help later. */
        if (dlthis->tramp.string_head == NULL) {
            priv_tramp_string_create(dlthis,
                         strlen(TRAMP_SECT_NAME),
                         TRAMP_SECT_NAME);
        }
#ifdef ENABLE_TRAMP_DEBUG
        dload_syms_error(dlthis->mysym,
                 "Trampoline at img loc %x, references %x",
                 dlthis->ldr_sections[secnn].run_addr +
                 image_offset + rp->vaddr,
                 dlthis->local_symtab[rp->SYMNDX].value);
#endif

        /*  Generate the trampoline string, check if already defined.
         * If the relo symbol index is -1, it means we need the section
         * info for relo later.  To do this we'll dummy up a symbol
         * with the section delta and run addresses. */
        if (rp->SYMNDX == -1) {
            ext_tmp_sym.value =
                dlthis->ldr_sections[secnn].run_addr;
            ext_tmp_sym.delta = dlthis->sect_hdrs[secnn].ds_paddr;
            ref_sym = &ext_tmp_sym;
        } else
            ref_sym = &(dlthis->local_symtab[rp->SYMNDX]);

        priv_tramp_sym_gen_name(ref_sym->value, tramp_sym_str);
        new_tramp_sym = priv_tramp_sym_find(dlthis, tramp_sym_str);
        if (new_tramp_sym == NULL) {
            /*  If tramp string not defined, create it and a new
             * string, and symbol for it as well as the original
             * symbol which caused the trampoline. */
            new_tramp_str = priv_tramp_string_create(dlthis,
                                strlen
                                (tramp_sym_str),
                                 tramp_sym_str);
            if (new_tramp_str == NULL) {
                dload_error(dlthis, "Failed to create new "
                        "trampoline string\n");
                ret_val = 0;
            } else {
                /*  Allocate tramp section space for the new
                 * tramp from the target */
                new_tramp_base = priv_tramp_sect_alloc(dlthis,
                               tramp_size_get());

                /*  We have a string, create the new symbol and
                 * duplicate the external. */
                tmp_sym.value = new_tramp_base;
                tmp_sym.delta = 0;
                tmp_sym.secnn = -1;
                tmp_sym.sclass = 0;
                new_tramp_sym = priv_tramp_sym_create(dlthis,
                                  new_tramp_str->
                                  index,
                                  &tmp_sym);

                new_ext_sym = priv_tramp_sym_create(dlthis, -1,
                                    ref_sym);

                if ((new_tramp_sym != NULL) &&
                    (new_ext_sym != NULL)) {
                    /*  Call the image generator to get the
                     * new image data and fix up its
                     * relocations for the external
                     * symbol. */
                    ret_val = priv_tgt_img_gen(dlthis,
                                 new_tramp_base,
                                 gen_index,
                                 new_ext_sym);

                    /*  Add generated image data to tramp
                     * image list */
                    if (ret_val != 1) {
                        dload_error(dlthis, "Failed to "
                                "create img pkt for"
                                " trampoline\n");
                    }
                } else {
                    dload_error(dlthis, "Failed to create "
                            "new tramp syms "
                            "(%8.8X, %8.8X)\n",
                            new_tramp_sym, new_ext_sym);
                    ret_val = 0;
                }
            }
        }

        /*  Duplicate the image data and relo record that caused the
         * tramp, including update the relo data to point to the tramp
         * symbol. */
        if (ret_val == 1) {
            ret_val = priv_img_pkt_dup(dlthis, secnn, image_offset,
                           ipacket, rp, new_tramp_sym);
            if (ret_val != 1) {
                dload_error(dlthis, "Failed to create dup of "
                        "original img pkt\n");
            }
        }
    }

    return ret_val;
}

/*
 * Function:    dload_tramp_pkt_update
 * Description: Update the duplicate copy of this image packet, which the
 *    trampoline layer is already tracking.  This call is critical
 *    to make if trampolines were generated anywhere within the
 *    packet and first pass relo continued on the remainder.  The
 *    trampoline layer needs the updates image data so when 2nd
 *    pass relo is done during finalize the image packet can be
 *    written to the target since all relo is done.
 */
int dload_tramp_pkt_udpate(struct dload_state *dlthis, s16 secnn,
               u32 image_offset, struct image_packet_t *ipacket)
{
    struct tramp_img_dup_pkt *dup_pkt = NULL;
    s32 i;
    int ret_val = 0;

    /*  Find the image packet in question, the caller needs us to update it
       since a trampoline was previously generated. */
    dup_pkt = priv_dup_find(dlthis, secnn, image_offset);
    if (dup_pkt != NULL) {
        for (i = 0; i < dup_pkt->img_pkt.packet_size; i++)
            *(dup_pkt->img_pkt.img_data + i) =
                *(ipacket->img_data + i);

        ret_val = 1;
    } else {
        dload_error(dlthis,
                "Unable to find existing DUP pkt for %x, offset %x",
                secnn, image_offset);

    }

    return ret_val;
}

/*
 * Function:    dload_tramp_finalize
 * Description: If any trampolines were created, finalize everything on the
 *    target by allocating the trampoline section on the target,
 *    finalizing the trampoline symbols, finalizing the trampoline
 *    packets (write the new section to target memory) and finalize
 *    the duplicate packets by doing 2nd pass relo over them.
 */
int dload_tramp_finalize(struct dload_state *dlthis)
{
    int ret_val = 1;

    if (dlthis->tramp.tramp_sect_next_addr != 0) {
        /*  Finalize strings into a flat table.  This is needed so it
         * can be added to the debug string table later. */
        ret_val = priv_string_tbl_finalize(dlthis);

        /*  Do target allocation for section BEFORE finalizing
         * symbols. */
        if (ret_val != 0)
            ret_val = priv_tramp_sect_tgt_alloc(dlthis);

        /*  Finalize symbols with their correct target information and
         * flatten */
        if (ret_val != 0)
            ret_val = priv_tramp_sym_finalize(dlthis);

        /*  Finalize all trampoline packets.  This performs the
         * relocation on the packets as well as writing them to target
         * memory. */
        if (ret_val != 0)
            ret_val = priv_tramp_pkt_finalize(dlthis);

        /*  Perform a 2nd pass relocation on the dup list. */
        if (ret_val != 0)
            ret_val = priv_dup_pkt_finalize(dlthis);
    }

    return ret_val;
}

/*
 * Function:    dload_tramp_cleanup
 * Description: Release all temporary resources used in the trampoline layer.
 *    Note that the target memory which may have been allocated and
 *    written to store the trampolines is NOT RELEASED HERE since it
 *    is potentially still in use.  It is automatically released
 *    when the module is unloaded.
 */
void dload_tramp_cleanup(struct dload_state *dlthis)
{
    struct tramp_info *tramp = &dlthis->tramp;
    struct tramp_sym *cur_sym;
    struct tramp_string *cur_string;
    struct tramp_img_pkt *cur_tramp_pkt;
    struct tramp_img_dup_pkt *cur_dup_pkt;
    struct tramp_img_dup_relo *cur_dup_relo;

    /*  If there were no tramps generated, just return */
    if (tramp->tramp_sect_next_addr == 0)
        return;

    /*  Destroy all tramp information */
    for (cur_sym = tramp->symbol_head;
         cur_sym != NULL; cur_sym = tramp->symbol_head) {
        tramp->symbol_head = cur_sym->next;
        if (tramp->symbol_tail == cur_sym)
            tramp->symbol_tail = NULL;

        dlthis->mysym->dload_deallocate(dlthis->mysym, cur_sym);
    }

    if (tramp->final_sym_table != NULL)
        dlthis->mysym->dload_deallocate(dlthis->mysym,
                        tramp->final_sym_table);

    for (cur_string = tramp->string_head;
         cur_string != NULL; cur_string = tramp->string_head) {
        tramp->string_head = cur_string->next;
        if (tramp->string_tail == cur_string)
            tramp->string_tail = NULL;

        dlthis->mysym->dload_deallocate(dlthis->mysym, cur_string);
    }

    if (tramp->final_string_table != NULL)
        dlthis->mysym->dload_deallocate(dlthis->mysym,
                        tramp->final_string_table);

    for (cur_tramp_pkt = tramp->tramp_pkts;
         cur_tramp_pkt != NULL; cur_tramp_pkt = tramp->tramp_pkts) {
        tramp->tramp_pkts = cur_tramp_pkt->next;
        dlthis->mysym->dload_deallocate(dlthis->mysym, cur_tramp_pkt);
    }

    for (cur_dup_pkt = tramp->dup_pkts;
         cur_dup_pkt != NULL; cur_dup_pkt = tramp->dup_pkts) {
        tramp->dup_pkts = cur_dup_pkt->next;

        for (cur_dup_relo = cur_dup_pkt->relo_chain;
             cur_dup_relo != NULL;
             cur_dup_relo = cur_dup_pkt->relo_chain) {
            cur_dup_pkt->relo_chain = cur_dup_relo->next;
            dlthis->mysym->dload_deallocate(dlthis->mysym,
                            cur_dup_relo);
        }

        dlthis->mysym->dload_deallocate(dlthis->mysym, cur_dup_pkt);
    }
}