rgbds/src/link/assign.c

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

#include "extern/err.h"
#include "link/assign.h"
#include "link/mylink.h"
#include "link/main.h"
#include "link/script.h"
#include "link/symbol.h"

struct sFreeArea {
	SLONG nOrg;
	SLONG nSize;
	struct sFreeArea *pPrev, *pNext;
};

struct sSectionAttributes {
	const char *name;
	SLONG bank;
	SLONG offset; // bank + offset = bank originally stored in a section struct
	SLONG minBank;
	SLONG bankCount;
};

struct sFreeArea *BankFree[MAXBANKS];
SLONG MaxAvail[MAXBANKS];
SLONG MaxBankUsed;
SLONG MaxWBankUsed;
SLONG MaxSBankUsed;
SLONG MaxVBankUsed;

const enum eSectionType SECT_MIN = SECT_WRAM0;
const enum eSectionType SECT_MAX = SECT_OAM;
const struct sSectionAttributes SECT_ATTRIBUTES[] = {
	{"WRAM0", BANK_WRAM0, 0, 0, BANK_COUNT_WRAM0},
	{"VRAM",  BANK_VRAM,  0, 0, BANK_COUNT_VRAM},
	{"ROMX",  BANK_ROMX, -1, 1, BANK_COUNT_ROMX},
	{"ROM0",  BANK_ROM0,  0, 0, BANK_COUNT_ROM0},
	{"HRAM",  BANK_HRAM,  0, 0, BANK_COUNT_HRAM},
	{"WRAMX", BANK_WRAMX, 0, 0, BANK_COUNT_WRAMX},
	{"SRAM",  BANK_SRAM,  0, 0, BANK_COUNT_SRAM},
	{"OAM",   BANK_OAM,   0, 0, BANK_COUNT_OAM}
};

#define DOMAXBANK(x, y) {switch (x) { \
	case SECT_ROMX: DOMAXRBANK(y); break; \
	case SECT_WRAMX: DOMAXWBANK(y); break; \
	case SECT_SRAM: DOMAXSBANK(y); break; \
	case SECT_VRAM: DOMAXVBANK(y); break; \
	default: break; }}
#define DOMAXRBANK(x)	{if( (x)>MaxBankUsed ) MaxBankUsed=(x);}
#define DOMAXWBANK(x)	{if( (x)>MaxWBankUsed ) MaxWBankUsed=(x);}
#define DOMAXSBANK(x)	{if( (x)>MaxSBankUsed ) MaxSBankUsed=(x);}
#define DOMAXVBANK(x)	{if( (x)>MaxVBankUsed ) MaxVBankUsed=(x);}

void
ensureSectionTypeIsValid(enum eSectionType type)
{
	if (type < SECT_MIN || type > SECT_MAX) {
		errx(1, "(INTERNAL) Invalid section type found.");
	}
}

SLONG
area_Avail(SLONG bank)
{
	SLONG r;
	struct sFreeArea *pArea;

	r = 0;
	pArea = BankFree[bank];

	while (pArea) {
		r += pArea->nSize;
		pArea = pArea->pNext;
	}

	return (r);
}

SLONG
area_doAlloc(struct sFreeArea *pArea, SLONG org, SLONG size)
{
	if (org >= pArea->nOrg && (org + size) <= (pArea->nOrg + pArea->nSize)) {
		if (org == pArea->nOrg) {
			pArea->nOrg += size;
			pArea->nSize -= size;
			return org;
		} else {
			if ((org + size) == (pArea->nOrg + pArea->nSize)) {
				pArea->nSize -= size;
				return org;
			} else {
				struct sFreeArea *pNewArea;

				if ((pNewArea = malloc(sizeof(struct sFreeArea))) != NULL) {
					*pNewArea = *pArea;
					pNewArea->pPrev = pArea;
					pArea->pNext = pNewArea;
					pArea->nSize = org - pArea->nOrg;
					pNewArea->nOrg = org + size;
					pNewArea->nSize -= size + pArea->nSize;
					return org;

				} else {
					err(1, NULL);
				}
			}
		}
	}

	return -1;
}

SLONG
area_AllocAbs(struct sFreeArea ** ppArea, SLONG org, SLONG size)
{
	struct sFreeArea *pArea;

	pArea = *ppArea;
	while (pArea) {
		SLONG result = area_doAlloc(pArea, org, size);
		if (result != -1) {
			return result;
		}

		ppArea = &(pArea->pNext);
		pArea = *ppArea;
	}

	return -1;
}

SLONG
area_AllocAbsAnyBank(SLONG org, SLONG size, enum eSectionType type)
{
	ensureSectionTypeIsValid(type);

	SLONG startBank = SECT_ATTRIBUTES[type].bank;
	SLONG bankCount = SECT_ATTRIBUTES[type].bankCount;

	for (int i = 0; i < bankCount; i++) {
		if (area_AllocAbs(&BankFree[startBank + i], org, size) != -1) {
			return startBank + i;
		}
	}

	return -1;
}

SLONG
area_Alloc(struct sFreeArea ** ppArea, SLONG size, SLONG alignment) {
	struct sFreeArea *pArea;
	if (alignment < 1) {
		alignment = 1;
	}

	pArea = *ppArea;
	while (pArea) {
		SLONG org = pArea->nOrg;
		if (org % alignment) {
			org += alignment;
		}
		org -= org % alignment;

		SLONG result = area_doAlloc(pArea, org, size);
		if (result != -1) {
			return result;
		}

		ppArea = &(pArea->pNext);
		pArea = *ppArea;
	}

	return -1;
}

SLONG
area_AllocAnyBank(SLONG size, SLONG alignment, enum eSectionType type) {
	ensureSectionTypeIsValid(type);

	SLONG startBank = SECT_ATTRIBUTES[type].bank;
	SLONG bankCount = SECT_ATTRIBUTES[type].bankCount;

	for (int i = 0; i < bankCount; i++) {
		SLONG org = area_Alloc(&BankFree[startBank + i], size, alignment);
		if (org != -1) {
			return ((startBank + i) << 16) | org;
		}
	}

	return -1;
}

struct sSection *
FindLargestSection(enum eSectionType type, bool bankFixed)
{
	struct sSection *pSection, *r = NULL;
	SLONG nLargest = 0;
	SLONG nLargestAlignment = 0;

	pSection = pSections;
	while (pSection) {
		if (pSection->oAssigned == 0 && pSection->Type == type && (bankFixed ^ (pSection->nBank == -1))) {
			if (pSection->nAlign > nLargestAlignment || (pSection->nAlign == nLargestAlignment && pSection->nByteSize > nLargest)) {
				nLargest = pSection->nByteSize;
				nLargestAlignment = pSection->nAlign;
				r = pSection;
			}
		}
		pSection = pSection->pNext;
	}

	return r;
}

int
IsSectionNameInUse(const char *name)
{
	struct sSection *pSection;

	pSection = pSections;
	while (pSection) {
		if (strcmp(pSection->pzName, name) == 0)
			return 1;

		pSection = pSection->pNext;
	}

	return 0;
}


int
IsSectionSameTypeBankAndFloating(const char *name, enum eSectionType type, int bank)
{
	struct sSection *pSection;

	pSection = pSections;
	while (pSection) {
		if (pSection->oAssigned == 0) {
			if (strcmp(pSection->pzName, name) == 0) {
				/* Section must be floating in source */
				if (pSection->nOrg != -1 || pSection->nAlign != 1)
					return 0;
				/* It must have the same type in source and linkerscript */
				if (pSection->Type != type)
					return 0;
				/* Bank number must be unassigned in source or equal */
				if (pSection->nBank != -1 && pSection->nBank != bank)
					return 0;
				return 1;
			}
		}
		pSection = pSection->pNext;
	}

	errx(1, "Section \"%s\" not found (or already used).\n", name);
}

unsigned int
AssignSectionAddressAndBankByName(const char *name, unsigned int address, int bank)
{
	struct sSection *pSection;

	pSection = pSections;
	while (pSection) {
		if (pSection->oAssigned == 0) {
			if (strcmp(pSection->pzName, name) == 0) {
				if (pSection->nOrg != -1 || pSection->nAlign != 1)
					errx(1, "Section \"%s\" from linkerscript isn't floating.\n", name);
				if (pSection->nBank != -1 && pSection->nBank != bank)
					errx(1, "Section \"%s\" from linkerscript has different bank number than in the source.\n", name);
				pSection->nOrg = address;
				pSection->nBank = bank;
				pSection->nAlign = -1;
				return pSection->nByteSize;
			}
		}
		pSection = pSection->pNext;
	}

	errx(1, "Section \"%s\" not found (or already used).\n", name);
}

bool
VerifyAndSetBank(struct sSection *pSection)
{
	ensureSectionTypeIsValid(pSection->Type);

	if (pSection->nBank >= SECT_ATTRIBUTES[pSection->Type].minBank
		&& pSection->nBank < SECT_ATTRIBUTES[pSection->Type].minBank + SECT_ATTRIBUTES[pSection->Type].bankCount) {
		pSection->nBank += SECT_ATTRIBUTES[pSection->Type].bank + SECT_ATTRIBUTES[pSection->Type].offset;
		return true;

	} else {
		return false;
	}
}

void
AssignFixedBankSections(enum eSectionType type)
{
	ensureSectionTypeIsValid(type);

	struct sSection *pSection;

	while ((pSection = FindLargestSection(type, true))) {
		if (VerifyAndSetBank(pSection) &&
			(pSection->nOrg = area_Alloc(&BankFree[pSection->nBank], pSection->nByteSize, pSection->nAlign)) != -1) {
			pSection->oAssigned = 1;
			DOMAXBANK(pSection->Type, pSection->nBank);
		} else {
			if (pSection->nAlign <= 1) {
				errx(1, "Unable to place '%s' (%s section) in bank $%02lX",
					pSection->pzName, SECT_ATTRIBUTES[pSection->Type].name, pSection->nBank);
			} else {
				errx(1, "Unable to place '%s' (%s section) in bank $%02lX (with $%lX-byte alignment)",
					pSection->pzName, SECT_ATTRIBUTES[pSection->Type].name, pSection->nBank, pSection->nAlign);
			}
		}
	}
}

void
AssignFloatingBankSections(enum eSectionType type)
{
	ensureSectionTypeIsValid(type);

	struct sSection *pSection;

	while ((pSection = FindLargestSection(type, false))) {
		SLONG org;

		if ((org = area_AllocAnyBank(pSection->nByteSize, pSection->nAlign, type)) != -1) {
			if (options & OPT_OVERLAY) {
				errx(1, "All sections must be fixed when using overlay");
			}
			pSection->nOrg = org & 0xFFFF;
			pSection->nBank = org >> 16;
			pSection->oAssigned = 1;
			DOMAXBANK(pSection->Type, pSection->nBank);
		} else {
			const char *locality = "anywhere";
			if (SECT_ATTRIBUTES[pSection->Type].bankCount > 1) {
				locality = "in any bank";
			}

			if (pSection->nAlign <= 1) {
				errx(1, "Unable to place '%s' (%s section) %s",
					 pSection->pzName, SECT_ATTRIBUTES[type].name, locality);
			} else {
				errx(1, "Unable to place '%s' (%s section) %s (with $%lX-byte alignment)",
					 pSection->pzName, SECT_ATTRIBUTES[type].name, locality, pSection->nAlign);
			}
		}
	}
}

char *tzLinkerscriptName = NULL;

void
SetLinkerscriptName(char *tzLinkerscriptFile)
{
	tzLinkerscriptName = tzLinkerscriptFile;
}

void
AssignSections(void)
{
	SLONG i;
	struct sSection *pSection;

	MaxBankUsed = 0;

	/*
	 * Initialize the memory areas
	 *
	 */

	for (i = 0; i < MAXBANKS; i += 1) {
		BankFree[i] = malloc(sizeof *BankFree[i]);

		if (!BankFree[i]) {
			err(1, NULL);
		}

		if (i == BANK_ROM0) {
			/* ROM0 bank */
			BankFree[i]->nOrg = 0x0000;
			if (options & OPT_TINY) {
				BankFree[i]->nSize = 0x8000;
			} else {
				BankFree[i]->nSize = 0x4000;
			}
		} else if (i >= BANK_ROMX && i < BANK_ROMX + BANK_COUNT_ROMX) {
			/* Swappable ROM bank */
			BankFree[i]->nOrg = 0x4000;
			BankFree[i]->nSize = 0x4000;
		} else if (i == BANK_WRAM0) {
			/* WRAM */
			BankFree[i]->nOrg = 0xC000;
			if (options & OPT_DMG_MODE) {
				BankFree[i]->nSize = 0x2000;
			} else {
				BankFree[i]->nSize = 0x1000;
			}
		} else if (i >= BANK_SRAM && i < BANK_SRAM + BANK_COUNT_SRAM) {
			/* Swappable SRAM bank */
			BankFree[i]->nOrg = 0xA000;
			BankFree[i]->nSize = 0x2000;
		} else if (i >= BANK_WRAMX && i < BANK_WRAMX + BANK_COUNT_WRAMX) {
			/* Swappable WRAM bank */
			BankFree[i]->nOrg = 0xD000;
			BankFree[i]->nSize = 0x1000;
		} else if (i >= BANK_VRAM && i < BANK_VRAM + BANK_COUNT_VRAM) {
			/* Swappable VRAM bank */
			BankFree[i]->nOrg = 0x8000;
			if (options & OPT_DMG_MODE && i != BANK_VRAM) {
				BankFree[i]->nSize = 0;
			} else {
				BankFree[i]->nSize = 0x2000;
			}
		} else if (i == BANK_OAM) {
			BankFree[i]->nOrg = 0xFE00;
			BankFree[i]->nSize = 0x00A0;
		} else if (i == BANK_HRAM) {
			/* HRAM */
			BankFree[i]->nOrg = 0xFF80;
			BankFree[i]->nSize = 0x007F;
		} else {
			errx(1, "(INTERNAL) Unknown bank type!");
		}

		MaxAvail[i] = BankFree[i]->nSize;
		BankFree[i]->pPrev = NULL;
		BankFree[i]->pNext = NULL;
	}

	/*
	 * First, let's parse the linkerscript.
	 *
	 */

	if (tzLinkerscriptName) {
		script_InitSections();
		script_Parse(tzLinkerscriptName);
	}

	/*
	 * Second, let's assign all the fixed sections...
	 *
	 */

	pSection = pSections;
	while (pSection) {
		if ((pSection->nOrg != -1 || pSection->nBank != -1)
		    && pSection->oAssigned == 0) {
			/* User wants to have a say... */

			switch (pSection->Type) {
			case SECT_WRAM0:
			case SECT_HRAM:
			case SECT_ROM0:
			case SECT_OAM:
				pSection->nBank = SECT_ATTRIBUTES[pSection->Type].bank;
				if (area_AllocAbs(&BankFree[pSection->nBank], pSection->nOrg,
					 pSection->nByteSize) == -1) {
					errx(1, "Unable to place '%s' (%s section) at $%lX",
						 pSection->pzName, SECT_ATTRIBUTES[pSection->Type].name, pSection->nOrg);
				}
				pSection->oAssigned = 1;
				break;

			case SECT_SRAM:
			case SECT_WRAMX:
			case SECT_VRAM:
			case SECT_ROMX:
				if (pSection->nBank != -1 && pSection->nOrg != -1) {
					if (VerifyAndSetBank(pSection) &&
						area_AllocAbs(&BankFree[pSection->nBank], pSection->nOrg, pSection->nByteSize) != -1) {
						DOMAXBANK(pSection->Type, pSection->nBank);
						pSection->oAssigned = 1;
					} else {
						errx(1, "Unable to place '%s' (%s section) at $%lX in bank $%02lX",
							pSection->pzName, SECT_ATTRIBUTES[pSection->Type].name, pSection->nOrg, pSection->nBank);
					}
				}
				break;
			}
		}
		pSection = pSection->pNext;
	}

	/*
	 * Next, let's assign all the bankfixed ONLY sections...
	 *
	 */
	for (enum eSectionType i = SECT_MIN; i <= SECT_MAX; i++) {
		AssignFixedBankSections(i);
	}

	/*
	 * Now, let's assign all the floating bank but fixed ROMX sections...
	 *
	 */

	pSection = pSections;
	while (pSection) {
		if (pSection->oAssigned == 0
			&& pSection->nOrg != -1 && pSection->nBank == -1) {
			if (options & OPT_OVERLAY) {
				errx(1, "All sections must be fixed when using overlay");
			}
			switch (pSection->Type) {
			case SECT_ROMX:
			case SECT_VRAM:
			case SECT_SRAM:
			case SECT_WRAMX:
				if ((pSection->nBank =
					area_AllocAbsAnyBank(pSection->nOrg, pSection->nByteSize,
						pSection->Type)) == -1) {
					errx(1, "Unable to place '%s' (%s section) at $%lX in any bank",
						 pSection->pzName, SECT_ATTRIBUTES[pSection->Type].name, pSection->nOrg);
				}
				pSection->oAssigned = 1;
				DOMAXBANK(pSection->Type, pSection->nBank);
				break;

			default: // Handle other sections later
				break;
			}
		}

		pSection = pSection->pNext;
	}

	/*
	 * OK, all that nasty stuff is done so let's assign all the other
	 * sections
	 *
	 */
	for (enum eSectionType i = SECT_MIN; i <= SECT_MAX; i++) {
		AssignFloatingBankSections(i);
	}
}

void
CreateSymbolTable(void)
{
	struct sSection *pSect;

	sym_Init();

	pSect = pSections;

	while (pSect) {
		SLONG i;

		i = pSect->nNumberOfSymbols;

		while (i--) {
			if ((pSect->tSymbols[i]->Type == SYM_EXPORT) &&
			    ((pSect->tSymbols[i]->pSection == pSect) ||
				(pSect->tSymbols[i]->pSection == NULL))) {
				if (pSect->tSymbols[i]->pSection == NULL)
					sym_CreateSymbol(pSect->tSymbols[i]->
					    pzName,
					    pSect->tSymbols[i]->
					    nOffset, -1);
				else
					sym_CreateSymbol(pSect->tSymbols[i]->
					    pzName,
					    pSect->nOrg +
					    pSect->tSymbols[i]->
					    nOffset, pSect->nBank);
			}
		}
		pSect = pSect->pNext;
	}
}