ref: e400eac42b497ca11387de0a7f3e8100d33cf6ab
dir: /src/link/patch.c/
/* * This file is part of RGBDS. * * Copyright (c) 1997-2018, Carsten Sorensen and RGBDS contributors. * * SPDX-License-Identifier: MIT */ #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include "extern/err.h" #include "link/assign.h" #include "link/main.h" #include "link/mylink.h" #include "link/symbol.h" static struct sSection *pCurrentSection; static int32_t rpnstack[256]; static int32_t rpnp; int32_t nPC; static void rpnpush(int32_t i) { rpnstack[rpnp] = i; rpnp++; } static int32_t rpnpop(void) { rpnp--; return rpnstack[rpnp]; } static int32_t getsymvalue(struct sPatch *pPatch, int32_t symid) { const struct sSymbol *tSymbol = pCurrentSection->tSymbols[symid]; switch (tSymbol->Type) { case SYM_IMPORT: return sym_GetValue(pPatch, tSymbol->pzName); case SYM_EXPORT: case SYM_LOCAL: if (strcmp(tSymbol->pzName, "@") == 0) return nPC; return tSymbol->nOffset + tSymbol->pSection->nOrg; default: break; } errx(1, "%s: Unknown symbol type", __func__); } static int32_t getrealbankfrominternalbank(int32_t n) { if (BankIndexIsWRAM0(n) || BankIndexIsROM0(n) || BankIndexIsOAM(n) || BankIndexIsHRAM(n)) { return 0; } else if (BankIndexIsROMX(n)) { return n - BANK_INDEX_ROMX + 1; } else if (BankIndexIsWRAMX(n)) { return n - BANK_INDEX_WRAMX + 1; } else if (BankIndexIsVRAM(n)) { return n - BANK_INDEX_VRAM; } else if (BankIndexIsSRAM(n)) { return n - BANK_INDEX_SRAM; } return n; } static int32_t getsymbank(struct sPatch *pPatch, int32_t symid) { int32_t nBank; const struct sSymbol *tSymbol = pCurrentSection->tSymbols[symid]; switch (tSymbol->Type) { case SYM_IMPORT: nBank = sym_GetBank(pPatch, tSymbol->pzName); break; case SYM_EXPORT: case SYM_LOCAL: nBank = tSymbol->pSection->nBank; break; default: errx(1, "%s: Unknown symbol type", __func__); } return getrealbankfrominternalbank(nBank); } int32_t calcrpn(struct sPatch *pPatch) { int32_t t, size; uint8_t *rpn; uint8_t rpn_cmd; int32_t nBank; rpnp = 0; size = pPatch->nRPNSize; rpn = pPatch->pRPN; pPatch->oRelocPatch = 0; while (size > 0) { size -= 1; rpn_cmd = *rpn++; switch (rpn_cmd) { case RPN_ADD: rpnpush(rpnpop() + rpnpop()); break; case RPN_SUB: t = rpnpop(); rpnpush(rpnpop() - t); break; case RPN_MUL: rpnpush(rpnpop() * rpnpop()); break; case RPN_DIV: t = rpnpop(); rpnpush(rpnpop() / t); break; case RPN_MOD: t = rpnpop(); rpnpush(rpnpop() % t); break; case RPN_UNSUB: rpnpush(-rpnpop()); break; case RPN_OR: rpnpush(rpnpop() | rpnpop()); break; case RPN_AND: rpnpush(rpnpop() & rpnpop()); break; case RPN_XOR: rpnpush(rpnpop() ^ rpnpop()); break; case RPN_UNNOT: rpnpush(~rpnpop()); break; case RPN_LOGAND: rpnpush(rpnpop() && rpnpop()); break; case RPN_LOGOR: rpnpush(rpnpop() || rpnpop()); break; case RPN_LOGUNNOT: rpnpush(!rpnpop()); break; case RPN_LOGEQ: rpnpush(rpnpop() == rpnpop()); break; case RPN_LOGNE: rpnpush(rpnpop() != rpnpop()); break; case RPN_LOGGT: t = rpnpop(); rpnpush(rpnpop() > t); break; case RPN_LOGLT: t = rpnpop(); rpnpush(rpnpop() < t); break; case RPN_LOGGE: t = rpnpop(); rpnpush(rpnpop() >= t); break; case RPN_LOGLE: t = rpnpop(); rpnpush(rpnpop() <= t); break; case RPN_SHL: t = rpnpop(); rpnpush(rpnpop() << t); break; case RPN_SHR: t = rpnpop(); rpnpush(rpnpop() >> t); break; case RPN_HRAM: t = rpnpop(); rpnpush(t & 0xFF); if (t < 0 || (t > 0xFF && t < 0xFF00) || t > 0xFFFF) { errx(1, "%s(%ld) : Value must be in the HRAM area", pPatch->pzFilename, pPatch->nLineNo); } break; case RPN_CONST: /* constant */ t = (*rpn++); t |= (*rpn++) << 8; t |= (*rpn++) << 16; t |= (*rpn++) << 24; rpnpush(t); size -= 4; break; case RPN_SYM: /* symbol */ t = (*rpn++); t |= (*rpn++) << 8; t |= (*rpn++) << 16; t |= (*rpn++) << 24; rpnpush(getsymvalue(pPatch, t)); pPatch->oRelocPatch |= (getsymbank(pPatch, t) != -1); size -= 4; break; case RPN_BANK_SYM: /* symbol */ t = (*rpn++); t |= (*rpn++) << 8; t |= (*rpn++) << 16; t |= (*rpn++) << 24; rpnpush(getsymbank(pPatch, t)); size -= 4; break; case RPN_BANK_SECT: { char *name = (char *)rpn; struct sSection *pSection = GetSectionByName(name); if (pSection == NULL) { errx(1, "%s(%ld) : Requested BANK() of section \"%s\", which was not found.\n", pPatch->pzFilename, pPatch->nLineNo, name); } nBank = pSection->nBank; rpnpush(getrealbankfrominternalbank(nBank)); int len = strlen(name); size -= len + 1; rpn += len + 1; break; } case RPN_BANK_SELF: nBank = pCurrentSection->nBank; rpnpush(getrealbankfrominternalbank(nBank)); break; default: errx(1, "%s: Invalid command %d\n", __func__, rpn_cmd); break; } } return rpnpop(); } void Patch(void) { struct sSection *pSect; pSect = pSections; while (pSect) { struct sPatch *pPatch; pCurrentSection = pSect; pPatch = pSect->pPatches; while (pPatch) { int32_t t; int32_t nPatchOrg; nPC = pSect->nOrg + pPatch->nOffset; t = calcrpn(pPatch); switch (pPatch->Type) { case PATCH_BYTE: if (t >= -128 && t <= 255) { t &= 0xFF; pSect->pData[pPatch->nOffset] = (uint8_t)t; } else { errx(1, "%s(%ld) : Value must be 8-bit", pPatch->pzFilename, pPatch->nLineNo); } break; case PATCH_WORD_L: if (t >= -32768 && t <= 65535) { t &= 0xFFFF; pSect->pData[pPatch->nOffset] = t & 0xFF; pSect->pData[pPatch->nOffset + 1] = (t >> 8) & 0xFF; } else { errx(1, "%s(%ld) : Value must be 16-bit", pPatch->pzFilename, pPatch->nLineNo); } break; case PATCH_LONG_L: pSect->pData[pPatch->nOffset + 0] = t & 0xFF; pSect->pData[pPatch->nOffset + 1] = (t >> 8) & 0xFF; pSect->pData[pPatch->nOffset + 2] = (t >> 16) & 0xFF; pSect->pData[pPatch->nOffset + 3] = (t >> 24) & 0xFF; break; case PATCH_BYTE_JR: /* Calculate absolute address of the patch */ nPatchOrg = pSect->nOrg + pPatch->nOffset; /* t contains the destination of the jump */ t = (int16_t)((t & 0xFFFF) - (nPatchOrg + 1)); if (t >= -128 && t <= 127) { t &= 0xFF; pSect->pData[pPatch->nOffset] = (uint8_t)t; } else { errx(1, "%s(%ld) : Value must be 8-bit", pPatch->pzFilename, pPatch->nLineNo); } break; default: errx(1, "%s: Internal error.", __func__); } pPatch = pPatch->pNext; } pSect = pSect->pNext; } }