pm.c

uboot在arm处理器s3c2410的移植代码

{
    PMSREGS     sregs;
    ulong       linAddr;
    ulong       DSBaseAddr;

    /* Get the base address for the default DS selector */
    PM_segread(&sregs);
    DSBaseAddr = DPMI_getSelectorBase(sregs.ds);
    if ((base < 0x100000) && (DSBaseAddr == 0)) {
	/* DS is zero based, so we can directly access the first 1Mb of
	 * system memory (like under DOS4GW).
	 */
	return (void*)base;
	}

    /* Map the memory to a linear address using DPMI function 0x800 */
    if ((linAddr = DPMI_mapPhysicalToLinear(base,limit)) == 0xFFFFFFFF) {
	if (base >= 0x100000)
	    return NULL;
	/* If the linear address mapping fails but we are trying to
	 * map an area in the first 1Mb of system memory, then we must
	 * be running under a Windows or OS/2 DOS box. Under these
	 * environments we can use the segment wrap around as a fallback
	 * measure, as this does work properly.
	 */
	linAddr = base;
	}

    /* Now expand the default DS selector to 4Gb so we can access it */
    if (!DPMI_setSelectorLimit(sregs.ds,0xFFFFFFFFUL))
	return NULL;

    /* Finally enable caching for the page tables that we just mapped in,
     * since DOS4GW and PMODE/W create the page table entries without
     * caching enabled which hurts the performance of the linear framebuffer
     * as it disables write combining on Pentium Pro and above processors.
     *
     * For those processors cache disabling is better handled through the
     * MTRR registers anyway (we can write combine a region but disable
     * caching) so that MMIO register regions do not screw up.
     */
    if (DSBaseAddr == 0)
	PM_adjustPageTables(linAddr,limit,isCached);

    /* Now return the base address of the memory into the default DS */
    return (void*)(linAddr - DSBaseAddr);
}

#if defined(PM386)

/* Some DOS extender implementations do not directly support calling a
 * real mode procedure from protected mode. However we can simulate what
 * we need temporarily hooking the INT 6Ah vector with a small real mode
 * stub that will call our real mode code for us.
 */

static uchar int6AHandler[] = {
    0x00,0x00,0x00,0x00,        /*  __PMODE_callReal variable           */
    0xFB,                       /*  sti                                 */
    0x2E,0xFF,0x1E,0x00,0x00,   /*  call    [cs:__PMODE_callReal]       */
    0xCF,                       /*  iretf                               */
    };
static uchar *crPtr = NULL; /* Pointer to of int 6A handler         */
static uint crRSeg,crROff;  /* Real mode seg:offset of handler      */

void PMAPI PM_callRealMode(uint seg,uint off, RMREGS *in,
    RMSREGS *sregs)
{
    uchar   *p;
    uint    oldSeg,oldOff;

    if (!crPtr) {
	/* Allocate and copy the memory block only once */
	crPtr = PM_allocRealSeg(sizeof(int6AHandler), &crRSeg, &crROff);
	memcpy(crPtr,int6AHandler,sizeof(int6AHandler));
	}
    PM_setWord(crPtr,off);              /* Plug in address to call  */
    PM_setWord(crPtr+2,seg);
    p = PM_mapRealPointer(0,0x6A * 4);
    oldOff = PM_getWord(p);             /* Save old handler address */
    oldSeg = PM_getWord(p+2);
    PM_setWord(p,crROff+4);             /* Hook 6A handler          */
    PM_setWord(p+2,crRSeg);
    PM_int86x(0x6A, in, in, sregs);     /* Call real mode code      */
    PM_setWord(p,oldOff);               /* Restore old handler      */
    PM_setWord(p+2,oldSeg);
}

#endif  /* PM386 */

#endif  /* !REALMODE */

/****************************************************************************
REMARKS:
Allocates a block of locked, physically contiguous memory. The memory
may be required to be below the 16Meg boundary.
****************************************************************************/
void * PMAPI PM_allocLockedMem(
    uint size,
    ulong *physAddr,
    ibool contiguous,
    ibool below16Meg)
{
    uchar           *p,*roundedP;
    uint            r_seg,r_off;
    uint            roundedSize = (size + 4 + 0xFFF) & ~0xFFF;
    PM_lockHandle   lh; /* Unused in DOS */
#ifndef REALMODE
    VXD_regs        regs;

    /* If we have connected to our helper VxD in a Windows DOS box, use the
     * helper VxD services to allocate the memory that we need.
     */
    if (VXD_version) {
	memset(&regs,0,sizeof(regs));
	regs.eax = API_NUM(PMHELP_ALLOCLOCKED);
	regs.ebx = size;
	regs.ecx = (ulong)physAddr;
	regs.edx = contiguous | (below16Meg << 8);
	_PM_VxDCall(&regs,_PM_VXD_off,_PM_VXD_sel);
	return (void*)regs.eax;
	}

    /* If the memory is not contiguous, we simply need to allocate it
     * using regular memory allocation services, and lock it down
     * in memory.
     *
     * For contiguous memory blocks, the only way to guarantee contiguous physical
     * memory addresses under DOS is to allocate the memory below the
     * 1Meg boundary as real mode memory.
     *
     * Note that we must page align the memory block, and we also must
     * keep track of the non-aligned pointer so we can properly free
     * it later. Hence we actually allocate 4 bytes more than the
     * size rounded up to the next 4K boundary.
     */
    if (!contiguous)
	p = PM_malloc(roundedSize);
    else
#endif
	p = PM_allocRealSeg(roundedSize,&r_seg,&r_off);
    if (p == NULL)
	return NULL;
    roundedP = (void*)(((ulong)p + 0xFFF) & ~0xFFF);
    *((ulong*)(roundedP + size)) = (ulong)p;
    PM_lockDataPages(roundedP,size,&lh);
    if ((*physAddr = PM_getPhysicalAddr(roundedP)) == 0xFFFFFFFF) {
	PM_freeLockedMem(roundedP,size,contiguous);
	return NULL;
	}

    /* Disable caching for the memory since it is probably a DMA buffer */
#ifndef REALMODE
    PM_adjustPageTables((ulong)roundedP,size-1,false);
#endif
    return roundedP;
}

/****************************************************************************
REMARKS:
Free a block of locked memory.
****************************************************************************/
void PMAPI PM_freeLockedMem(void *p,uint size,ibool contiguous)
{
#ifndef REALMODE
    VXD_regs        regs;
    PM_lockHandle   lh; /* Unused in DOS */

    if (!p)
	return;
    if (VXD_version) {
	memset(&regs,0,sizeof(regs));
	regs.eax = API_NUM(PMHELP_FREELOCKED);
	regs.ebx = (ulong)p;
	regs.ecx = size;
	regs.edx = contiguous;
	_PM_VxDCall(&regs,_PM_VXD_off,_PM_VXD_sel);
	return;
	}
    PM_unlockDataPages(p,size,&lh);
    if (!contiguous)
	free(*((void**)((uchar*)p + size)));
    else
#endif
	PM_freeRealSeg(*((void**)((char*)p + size)));
}

#ifndef REALMODE
/****************************************************************************
REMARKS:
Allocates a new block of pages for the page block manager.
****************************************************************************/
static pageblock *PM_addNewPageBlock(void)
{
    int         i,size;
    pageblock   *newBlock;
    char        *p,*next;

    /* Allocate memory for the new page block, and add to head of list */
    size = PAGES_PER_BLOCK * PM_PAGE_SIZE + (PM_PAGE_SIZE-1) + sizeof(pageblock);
    if ((newBlock = PM_malloc(size)) == NULL)
	return NULL;
    newBlock->prev = NULL;
    newBlock->next = pageBlocks;
    if (pageBlocks)
	pageBlocks->prev = newBlock;
    pageBlocks = newBlock;

    /* Initialise the page aligned free list for the page block */
    newBlock->freeCount = PAGES_PER_BLOCK;
    newBlock->freeList = p = (char*)(((ulong)(newBlock + 1) + (PM_PAGE_SIZE-1)) & ~(PM_PAGE_SIZE-1));
    newBlock->freeListStart = newBlock->freeList;
    newBlock->freeListEnd = p + (PAGES_PER_BLOCK-1) * PM_PAGE_SIZE;
    for (i = 0; i < PAGES_PER_BLOCK; i++,p = next)
	FREELIST_NEXT(p) = next = p + PM_PAGE_SIZE;
    FREELIST_NEXT(p - PM_PAGE_SIZE) = NULL;
    return newBlock;
}
#endif

/****************************************************************************
REMARKS:
Allocates a page aligned and page sized block of memory
****************************************************************************/
void * PMAPI PM_allocPage(
    ibool locked)
{
#ifndef REALMODE
    VXD_regs        regs;
    pageblock       *block;
    void            *p;
    PM_lockHandle   lh; /* Unused in DOS */

    /* Call the helper VxD for this service if we are running in a DOS box */
    if (VXD_version) {
	memset(&regs,0,sizeof(regs));
	regs.eax = API_NUM(PMHELP_ALLOCPAGE);
	regs.ebx = locked;
	_PM_VxDCall(&regs,_PM_VXD_off,_PM_VXD_sel);
	return (void*)regs.eax;
	}

    /* Scan the block list looking for any free blocks. Allocate a new
     * page block if no free blocks are found.
     */
    for (block = pageBlocks; block != NULL; block = block->next) {
	if (block->freeCount)
	    break;
	}
    if (block == NULL && (block = PM_addNewPageBlock()) == NULL)
	return NULL;
    block->freeCount--;
    p = block->freeList;
    block->freeList = FREELIST_NEXT(p);
    if (locked)
	PM_lockDataPages(p,PM_PAGE_SIZE,&lh);
    return p;
#else
    return NULL;
#endif
}

/****************************************************************************
REMARKS:
Free a page aligned and page sized block of memory
****************************************************************************/
void PMAPI PM_freePage(
    void *p)
{
#ifndef REALMODE
    VXD_regs    regs;
    pageblock   *block;

    /* Call the helper VxD for this service if we are running in a DOS box */
    if (VXD_version) {
	memset(&regs,0,sizeof(regs));
	regs.eax = API_NUM(PMHELP_FREEPAGE);
	regs.ebx = (ulong)p;
	_PM_VxDCall(&regs,_PM_VXD_off,_PM_VXD_sel);
	return;
	}

    /* First find the page block that this page belongs to */
    for (block = pageBlocks; block != NULL; block = block->next) {
	if (p >= block->freeListStart && p <= block->freeListEnd)
	    break;
	}
    CHECK(block != NULL);

    /* Now free the block by adding it to the free list */
    FREELIST_NEXT(p) = block->freeList;
    block->freeList = p;
    if (++block->freeCount == PAGES_PER_BLOCK) {
	/* If all pages in the page block are now free, free the entire
	 * page block itself.
	 */
	if (block == pageBlocks) {
	    /* Delete from head */
	    pageBlocks = block->next;
	    if (block->next)
		block->next->prev = NULL;
	    }
	else {
	    /* Delete from middle of list */
	    CHECK(block->prev != NULL);
	    block->prev->next = block->next;
	    if (block->next)
		block->next->prev = block->prev;
	    }
	PM_free(block);
	}
#else
    (void)p;
#endif
}

/*-------------------------------------------------------------------------*/
/* DOS Real Mode support.                                                  */
/*-------------------------------------------------------------------------*/

#ifdef REALMODE

#ifndef MK_FP
#define MK_FP(s,o)  ( (void far *)( ((ulong)(s) << 16) + \
		    (ulong)(o) ))
#endif

void * PMAPI PM_mapRealPointer(uint r_seg,uint r_off)
{ return MK_FP(r_seg,r_off); }

void * PMAPI PM_getBIOSPointer(void)
{
    return MK_FP(0x40,0);
}

void * PMAPI PM_getA0000Pointer(void)
{
    return MK_FP(0xA000,0);
}

void * PMAPI PM_mapPhysicalAddr(ulong base,ulong limit,ibool isCached)
{
    uint sel = base >> 4;
    uint off = base & 0xF;
    limit = limit;
    return MK_FP(sel,off);
}

void PMAPI PM_freePhysicalAddr(void *ptr,ulong limit)
{ ptr = ptr; }

ulong PMAPI PM_getPhysicalAddr(void *p)
{
    return ((((ulong)p >> 16) << 4) + (ushort)p);
}

ibool PMAPI PM_getPhysicalAddrRange(void *p,ulong length,ulong *physAddress)
{ return false; }

void * PMAPI PM_mapToProcess(void *base,ulong limit)
{ return (void*)base; }

void * PMAPI PM_allocRealSeg(uint size,uint *r_seg,uint *r_off)
{
    /* Call malloc() to allocate the memory for us */
    void *p = PM_malloc(size);
    *r_seg = FP_SEG(p);
    *r_off = FP_OFF(p);
    return p;
}

void PMAPI PM_freeRealSeg(void *mem)
{
    if (mem) PM_free(mem);
}

int PMAPI PM_int86(int intno, RMREGS *in, RMREGS *out)
{
    return PM_int386(intno,in,out);
}

int PMAPI PM_int86x(int intno, RMREGS *in, RMREGS *out,
    RMSREGS *sregs)
{
    return PM_int386x(intno,in,out,sregs);
}

void PMAPI PM_availableMemory(ulong *physical,ulong *total)
{
    PMREGS regs;

    regs.h.ah = 0x48;
    regs.x.bx = 0xFFFF;
    PM_int86(0x21,&regs,&regs);
    *physical = *total = regs.x.bx * 16UL;
}

#endif

/*-------------------------------------------------------------------------*/
/* Phar Lap TNT DOS Extender support.                                      */
/*-------------------------------------------------------------------------*/

#ifdef TNT

#include <pldos32.h>
#include <pharlap.h>
#include <hw386.h>

static uchar *zeroPtr = NULL;

void * PMAPI PM_getBIOSPointer(void)
{
    if (!zeroPtr)
	zeroPtr = PM_mapPhysicalAddr(0,0xFFFFF,true);
    return (void*)(zeroPtr + 0x400);
}

void * PMAPI PM_getA0000Pointer(void)
{
    static void *bankPtr;
    if (!bankPtr)
	bankPtr = PM_mapPhysicalAddr(0xA0000,0xFFFF,true);
    return bankPtr;
}

void * PMAPI PM_mapPhysicalAddr(ulong base,ulong limit,ibool isCached)
{
    CONFIG_INF  config;
    ULONG       offset;
    int         err;
    ulong       baseAddr,baseOfs,newLimit;
    VXD_regs    regs;

    /* If we have connected to our helper VxD in a Windows DOS box, use
     * the helper VxD services to map memory instead of the DPMI services.
     * We do this because the helper VxD can properly disable caching
     * where necessary, which we can only do directly here if we are
     * running at ring 0 (ie: under real DOS).
     */
    if (VXD_version == -1)
	PM_init();
    if (VXD_version) {
	memset(&regs,0,sizeof(regs));
	regs.eax = API_NUM(PMHELP_MAPPHYS);
	regs.ebx = base;
	regs.ecx = limit;
	regs.edx = isCached;
	_PM_VxDCall(&regs,_PM_VXD_off,_PM_VXD_sel);
	return (void*)regs.eax;
	}

    /* Round the physical address to a 4Kb boundary and the limit to a
     * 4Kb-1 boundary before passing the values to TNT. If we round the
     * physical address, then we also add an extra offset into the address
     * that we return.
     */
    baseOfs = base & 4095;
    baseAddr = base & ~4095;
    newLimit = ((limit+baseOfs+1+4095) & ~4095)-1;
    _dx_config_inf(&config, (UCHAR*)&config);
    err = _dx_map_phys(config.c_ds_sel,baseAddr,(newLimit + 4095) / 4096,&offset);
    if (err == 130) {
	/* If the TNT function failed, we are running in a DPMI environment
	 * and this function does not work. However we know how to handle
	 * DPMI properly, so we use our generic DPMI functions to do
	 * what the TNT runtime libraries can't.
	 */
	return DPMI_mapPhysicalAddr(base,limit,isCached);
	}
    if (err == 0)
	return (void*)(offset + baseOfs);
    return NULL;
}

void PMAPI PM_freePhysicalAddr(void *ptr,ulong limit)
{
}

ulong PMAPI PM_getPhysicalAddr(void *p)
{ return 0xFFFFFFFFUL; }

ibool PMAPI PM_getPhysicalAddrRange(void *p,ulong length,ulong *physAddress)
{ return false; }

void * PMAPI PM_mapToProcess(void *base,ulong limit)
{ return (void*)base; }

void * PMAPI PM_mapRealPointer(uint r_seg,uint r_off)
{
    if (!zeroPtr)
	zeroPtr = PM_mapPhysicalAddr(0,0xFFFFF);
    return (void*)(zeroPtr + MK_PHYS(r_seg,r_off));
}

void * PMAPI PM_allocRealSeg(uint size,uint *r_seg,uint *r_off)
{
    USHORT  addr,t;
    void    *p;

    if (_dx_real_alloc((size + 0xF) >> 4,&addr,&t) != 0)
	return 0;
    *r_seg = addr;                  /* Real mode segment address    */
    *r_off = 0;                     /* Real mode segment offset     */
    p = PM_mapRealPointer(*r_seg,*r_off);
    _PM_addRealModeBlock(p,addr);
    return p;
}

void PMAPI PM_freeRealSeg(void *mem)
{
    if (mem) _dx_real_free(_PM_findRealModeBlock(mem));
}

#define INDPMI(reg)     rmregs.reg = regs->reg
#define OUTDPMI(reg)    regs->reg = rmregs.reg

void PMAPI DPMI_int86(int intno, DPMI_regs *regs)
{
    SWI_REGS    rmregs;

    memset(&rmregs, 0, sizeof(rmregs));
    INDPMI(eax); INDPMI(ebx); INDPMI(ecx); INDPMI(edx); INDPMI(esi); INDPMI(edi);

    _dx_real_int(intno,&rmregs);

    OUTDPMI(eax); OUTDPMI(ebx); OUTDPMI(ecx); OUTDPMI(edx); OUTDPMI(esi); OUTDPMI(edi);
    regs->flags = rmregs.flags;
}

#define IN(reg)     rmregs.reg = in->e.reg
#define OUT(reg)    out->e.reg = rmregs.reg

int PMAPI PM_int86(int intno, RMREGS *in, RMREGS *out)
{
    SWI_REGS    rmregs;

    memset(&rmregs, 0, sizeof(rmregs));
    IN(eax); IN(ebx); IN(ecx); IN(edx); IN(esi); IN(edi);

    _dx_real_int(intno,&rmregs);

    OUT(eax); OUT(ebx); OUT(ecx); OUT(edx); OUT(esi); OUT(edi);
    out->x.cflag = rmregs.flags & 0x1;
    return out->x.ax;
}

int PMAPI PM_int86x(int intno, RMREGS *in, RMREGS *out,
    RMSREGS *sregs)
{
    SWI_REGS    rmregs;

    memset(&rmregs, 0, sizeof(rmregs));
    IN(eax); IN(ebx); IN(ecx); IN(edx); IN(esi); IN(edi);
    rmregs.es = sregs->es;
    rmregs.ds = sregs->ds;

    _dx_real_int(intno,&rmregs);

    OUT(eax); OUT(ebx); OUT(ecx); OUT(edx); OUT(esi); OUT(edi);
    sregs->es = rmregs.es;