Merge tag 'v3.3.7' into 3.3/master

[zen-stable.git] / drivers / staging / tidspbridge / dynload / tramp.c

/*
 * 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 finaize 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;

        /*  Determinne 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 is 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);
        }
}