/*
 * Copyright 2003-2006, Axel Dörfler, axeld@pinc-software.de
 * Distributed under the terms of the MIT License.
 *
 * Copyright 2001, Travis Geiselbrecht. All rights reserved.
 * Copyright 2002, Manuel J. Petit. All rights reserved.
 * Distributed under the terms of the NewOS License.
 */


#include "runtime_loader_private.h"

#include <runtime_loader.h>

#include <string.h>
#include <stdio.h>
#include <stdlib.h>


//#define TRACE_RLD
#ifdef TRACE_RLD
#       define TRACE(x) dprintf x
#else
#       define TRACE(x) ;
#endif


static inline void
write_32(addr_t *P, Elf32_Word value)
{
        *(Elf32_Word*)P = value;
}


static inline void
write_16(addr_t *P, Elf32_Word value)
{
        // bits 16:29
        *(Elf32_Half*)P = (Elf32_Half)value;
}


static inline bool
write_16_check(addr_t *P, Elf32_Word value)
{
        // bits 15:0
        if ((value & 0xffff0000) && (~value & 0xffff8000))
                return false;
        *(Elf32_Half*)P = (Elf32_Half)value;
        return true;
}


static inline bool
write_8(addr_t *P, Elf32_Word value)
{
        // bits 7:0
        *(uint8 *)P = (uint8)value;
        return true;
}


static inline bool
write_8_check(addr_t *P, Elf32_Word value)
{
        // bits 7:0
        if ((value & 0xffffff00) && (~value & 0xffffff80))
                return false;
        *(uint8 *)P = (uint8)value;
        return true;
}


static int
relocate_rela(image_t *rootImage, image_t *image, Elf32_Rela *rel, int rel_len,
        SymbolLookupCache* cache)
{
        int i;
        addr_t S;
        addr_t final_val;

# define P      ((addr_t *)(image->regions[0].delta + rel[i].r_offset))
//# define A    (*(P))
#define A       ((addr_t)rel[i].r_addend)
# define B      (image->regions[0].delta)

        for (i = 0; i * (int)sizeof(Elf32_Rel) < rel_len; i++) {
                unsigned type = ELF32_R_TYPE(rel[i].r_info);

                switch (type) {
                        case R_68K_32:
                        case R_68K_16:
                        case R_68K_8:
                        case R_68K_PC32:
                        case R_68K_PC16:
                        case R_68K_PC8:
                        case R_68K_GLOB_DAT:
                        case R_68K_JMP_SLOT:
                        {
                                Elf32_Sym *sym;
                                status_t status;
                                sym = SYMBOL(image, ELF32_R_SYM(rel[i].r_info));

                                status = resolve_symbol(rootImage, image, sym, cache, &S);
                                if (status < B_OK) {
                                        TRACE(("resolve symbol \"%s\" returned: %ld\n",
                                                SYMNAME(image, sym), status));
                                        printf("resolve symbol \"%s\" returned: %ld\n",
                                                SYMNAME(image, sym), status);
                                        return status;
                                }
                        }
                }
                switch (type) {
                        case R_68K_NONE:
                                continue;
                        case R_68K_32:
                                write_32(P, S + A);
                                break;
                        case R_68K_16:
                                if (write_16_check(P, S + A))
                                        break;
                                TRACE(("R_68K_16 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_8:
                                if (write_8_check(P, S + A))
                                        break;
                                TRACE(("R_68K_8 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_PC32:
                                write_32(P, (S + A - (addr_t)P));
                                break;

#if 0
                        case R_68K_PC16:
                                if (write_16_check(P, (S + A - P)))
                                        break;
                                TRACE(("R_68K_PC16 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_PC8:
                                if (write_8(P, (S + A - P)))
                                        break;
                                TRACE(("R_68K_PC8 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_GOT32:
                                REQUIRE_GOT;
                                write_32(P, (G + A - P));
                                break;

                        case R_68K_GOT16:
                                REQUIRE_GOT;
                                if (write_16_check(P, (G + A - P)))
                                        break;
                                TRACE(("R_68K_GOT16 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_GOT8:
                                REQUIRE_GOT;
                                if (write_8_check(P, (G + A - P)))
                                        break;
                                TRACE(("R_68K_GOT8 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_GOT32O:
                                REQUIRE_GOT;
                                write_32(P, (G + A));
                                break;

                        case R_68K_GOT16O:
                                REQUIRE_GOT;
                                if (write_16_check(P, (G + A)))
                                        break;
                                TRACE(("R_68K_GOT16 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_GOT8O:
                                REQUIRE_GOT;
                                if (write_8_check(P, (G + A)))
                                        break;
                                TRACE(("R_68K_GOT8 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_PLT32:
                                REQUIRE_PLT;
                                write_32(P, (L + A - P));
                                break;

                        case R_68K_PLT16:
                                REQUIRE_PLT;
                                if (write_16_check(P, (L + A - P)))
                                        break;
                                TRACE(("R_68K_PLT16 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_PLT8:
                                REQUIRE_PLT;
                                if (write_8_check(P, (L + A - P)))
                                        break;
                                TRACE(("R_68K_PLT8 overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_PLT32O:
                                REQUIRE_PLT;
                                write_32(P, (L + A));
                                break;

                        case R_68K_PLT16O:
                                REQUIRE_PLT;
                                if (write_16_check(P, (L + A)))
                                        break;
                                TRACE(("R_68K_PLT16O overflow\n"));
                                return B_BAD_DATA;

                        case R_68K_PLT8O:
                                REQUIRE_PLT;
                                if (write_8_check(P, (L + A)))
                                        break;
                                TRACE(("R_68K_PLT8O overflow\n"));
                                return B_BAD_DATA;
                        case R_386_GOT32:
                                final_val = G + A;
                                break;
                        case R_386_PLT32:
                                final_val = L + A - (addr_t)P;
                                break;
#endif
                        case R_68K_COPY:
                                /* what ? */
                                continue;
                        case R_68K_GLOB_DAT:
                                write_32(P, S/* + A*/);
                                break;
                        case R_68K_JMP_SLOT:
                                //XXX ? write_32(P, (G + A));
                                write_32(P, S);
                                break;
#if 0
                        case R_386_JMP_SLOT:
                                write_32(P, S);
                                break;
#endif
                        case R_68K_RELATIVE:
                                write_32(P, B + A);
                                break;

#if 0
                        case R_386_GOTOFF:
                                final_val = S + A - GOT;
                                break;
                        case R_386_GOTPC:
                                final_val = GOT + A - P;
                                break;
#endif
                        default:
                                TRACE(("unhandled relocation type %d\n", ELF32_R_TYPE(rel[i].r_info)));
                                return B_NOT_ALLOWED;
                }

                *P = final_val;
        }

# undef P
# undef A
# undef B

        return B_NO_ERROR;
}


status_t
arch_relocate_image(image_t *rootImage, image_t *image,
        SymbolLookupCache* cache)
{
        status_t status;

        // deal with the rels first
        if (image->rel) {
                TRACE(("RELA relocations not supported\n"));
                return EOPNOTSUPP;
        }

        if (image->pltrel) {
                TRACE(("RELA relocations not supported\n"));
                return EOPNOTSUPP;
#if 0
                status = relocate_rel(rootImage, image, image->pltrel,
                        image->pltrel_len);
                if (status < B_OK)
                        return status;
#endif
        }

        if (image->rela) {
                status = relocate_rela(rootImage, image, image->rela, image->rela_len,
                        cache);
                //int i;
                if (status < B_OK)
                        return status;
                //TRACE(("RELA relocations not supported\n"));
                //return EOPNOTSUPP;

                //for (i = 1; i * (int)sizeof(Elf32_Rela) < image->rela_len; i++) {
                //      printf("rela: type %d\n", ELF32_R_TYPE(image->rela[i].r_info));
                //}
        }

#if 0
        if (image->pltrela) {
                status = relocate_rela(rootImage, image, image->pltrela,
                        image->pltrela_len);
                if (status < B_OK)
                        return status;
        }
#endif

        return B_OK;
}