443 lines
15 KiB
C
443 lines
15 KiB
C
/****************************************************************************
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* YABEL BIOS Emulator
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*
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* This program and the accompanying materials
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* are made available under the terms of the BSD License
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* which accompanies this distribution, and is available at
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* http://www.opensource.org/licenses/bsd-license.php
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*
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* Copyright (c) 2008 Pattrick Hueper <phueper@hueper.net>
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****************************************************************************/
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#include <x86emu/x86emu.h>
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#include "../x86emu/prim_ops.h"
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#include <string.h>
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#include "biosemu.h"
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#include "pmm.h"
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#include "debug.h"
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#include "device.h"
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/* this struct is used to remember which PMM spaces
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* have been assigned. MAX_PMM_AREAS defines how many
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* PMM areas we can assign.
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* All areas are assigned in PMM_CONV_SEGMENT
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*/
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typedef struct {
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u32 handle; /* handle that is returned to PMM caller */
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u32 offset; /* in PMM_CONV_SEGMENT */
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u32 length; /* length of this area */
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} pmm_allocation_t;
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#define MAX_PMM_AREAS 10
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/* array to store the above structs */
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static pmm_allocation_t pmm_allocation_array[MAX_PMM_AREAS];
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/* index into pmm_allocation_array */
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static u32 curr_pmm_allocation_index = 0;
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/* This function is used to setup the PMM struct in virtual memory
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* at a certain offset, the length of the PMM struct is returned */
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u8 pmm_setup(u16 segment, u16 offset)
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{
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/* setup the PMM structure */
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pmm_information_t *pis =
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(pmm_information_t *) (M.mem_base + (((u32) segment) << 4) +
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offset);
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memset(pis, 0, sizeof(pmm_information_t));
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/* set signature to $PMM */
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pis->signature[0] = '$';
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pis->signature[1] = 'P';
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pis->signature[2] = 'M';
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pis->signature[3] = 'M';
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/* revision as specified */
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pis->struct_rev = 0x01;
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/* internal length, excluding code */
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pis->length = ((void *)&(pis->code) - (void *)&(pis->signature));
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/* the code to be executed, pointed to by entry_point_offset */
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pis->code[0] = 0xCD; /* INT */
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pis->code[1] = PMM_INT_NUM; /* my selfdefined PMM INT number */
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pis->code[2] = 0xCB; /* RETF */
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/* set the entry_point_offset, it should point to pis->code, segment is the segment of
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* this struct. Since pis->length is the length of the struct excluding code, offset+pis->length
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* points to the code... it's that simple ;-)
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*/
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out32le(&(pis->entry_point_offset),
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(u32) segment << 16 | (u32) (offset + pis->length));
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/* checksum calculation */
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u8 i;
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u8 checksum = 0;
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for (i = 0; i < pis->length; i++) {
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checksum += *(((u8 *) pis) + i);
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}
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pis->checksum = ((u8) 0) - checksum;
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CHECK_DBG(DEBUG_PMM) {
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DEBUG_PRINTF_PMM("PMM Structure:\n");
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dump((void *)pis, sizeof(pmm_information_t));
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}
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return sizeof(pmm_information_t);
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}
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/* handle the selfdefined interrupt, this is executed, when the PMM Entry Point
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* is executed, it must handle all PMM requests
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*/
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void pmm_handleInt()
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{
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u32 rval = 0;
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u16 function, flags;
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u32 handle, length;
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u32 i, j;
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u32 buffer;
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/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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* according to the PMM Spec "the flags and all registers, except DX and AX
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* are preserved across calls to PMM"
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* so we save M.x86 and in :exit label we restore it, however, this means that no
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* returns must be used in this function, any exit must use goto exit!
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* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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*/
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X86EMU_regs backup_regs = M.x86;
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pop_long(); /* pop the return address, this is already saved in INT handler, we don't need
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to remember this. */
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function = pop_word();
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switch (function) {
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case 0:
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/* function pmmAllocate */
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length = pop_long();
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length *= 16; /* length is passed in "paragraphs" of 16 bytes each */
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handle = pop_long();
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flags = pop_word();
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DEBUG_PRINTF_PMM
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("%s: pmmAllocate: Length: %x, Handle: %x, Flags: %x\n",
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__func__, length, handle, flags);
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if ((flags & 0x1) != 0) {
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/* request to allocate in conventional memory */
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if (curr_pmm_allocation_index >= MAX_PMM_AREAS) {
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printf
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("%s: pmmAllocate: Maximum Number of allocatable areas reached (%d), cannot allocate more memory!\n",
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__func__, MAX_PMM_AREAS);
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rval = 0;
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goto exit;
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}
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/* some ROMs seem to be confused by offset 0, so lets start at 0x100 */
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u32 next_offset = 0x100;
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pmm_allocation_t *pmm_alloc =
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&(pmm_allocation_array[curr_pmm_allocation_index]);
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if (curr_pmm_allocation_index != 0) {
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/* we have already allocated... get the new next_offset
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* from the previous pmm_allocation_t */
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next_offset =
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pmm_allocation_array
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[curr_pmm_allocation_index - 1].offset +
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pmm_allocation_array
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[curr_pmm_allocation_index - 1].length;
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}
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DEBUG_PRINTF_PMM("%s: next_offset: 0x%x\n",
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__func__, next_offset);
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if (length == 0) {
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/* largest possible block size requested, we have on segment
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* to allocate, so largest possible is segment size (0xFFFF)
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* minus next_offset
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*/
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rval = 0xFFFF - next_offset;
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goto exit;
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}
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u32 align = 0;
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if (((flags & 0x4) != 0) && (length > 0)) {
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/* align to least significant bit set in length param */
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u8 lsb = 0;
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while (((length >> lsb) & 0x1) == 0) {
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lsb++;
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}
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align = 1 << lsb;
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}
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/* always align at least to paragraph (16byte) boundary
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* hm... since the length is always in paragraphs, we cannot
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* align outside of paragraphs anyway... so this check might
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* be unnecessary...*/
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if (align < 0x10) {
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align = 0x10;
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}
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DEBUG_PRINTF_PMM("%s: align: 0x%x\n", __func__,
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align);
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if ((next_offset & (align - 1)) != 0) {
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/* not yet aligned... align! */
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next_offset += align;
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next_offset &= ~(align - 1);
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}
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if ((next_offset + length) > 0xFFFF) {
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rval = 0;
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printf
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("%s: pmmAllocate: Not enough memory available for allocation!\n",
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__func__);
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goto exit;
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}
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curr_pmm_allocation_index++;
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/* remember the values in pmm_allocation_array */
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pmm_alloc->handle = handle;
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pmm_alloc->offset = next_offset;
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pmm_alloc->length = length;
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/* return the 32bit "physical" address, i.e. combination of segment and offset */
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rval = ((u32) (PMM_CONV_SEGMENT << 16)) | next_offset;
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DEBUG_PRINTF_PMM
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("%s: pmmAllocate: allocated memory at %x\n",
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__func__, rval);
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} else {
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rval = 0;
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printf
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("%s: pmmAllocate: allocation in extended memory not supported!\n",
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__func__);
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}
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goto exit;
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case 1:
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/* function pmmFind */
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handle = pop_long(); /* the handle to lookup */
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DEBUG_PRINTF_PMM("%s: pmmFind: Handle: %x\n", __func__,
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handle);
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i = 0;
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for (i = 0; i < curr_pmm_allocation_index; i++) {
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if (pmm_allocation_array[i].handle == handle) {
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DEBUG_PRINTF_PMM
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("%s: pmmFind: found allocated memory at %x\n",
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__func__, rval);
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/* return the 32bit "physical" address, i.e. combination of segment and offset */
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rval =
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((u32) (PMM_CONV_SEGMENT << 16)) |
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pmm_allocation_array[i].offset;
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}
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}
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if (rval == 0) {
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DEBUG_PRINTF_PMM
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("%s: pmmFind: handle (%x) not found!\n",
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__func__, handle);
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}
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goto exit;
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case 2:
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/* function pmmDeallocate */
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buffer = pop_long();
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/* since argument is the address of the PMM block (including the segment,
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* we need to remove the segment to get the offset
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*/
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buffer = buffer ^ ((u32) PMM_CONV_SEGMENT << 16);
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DEBUG_PRINTF_PMM("%s: pmmDeallocate: PMM segment offset: %x\n",
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__func__, buffer);
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i = 0;
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/* rval = 0 means we deallocated the buffer, so set it to 1 in case we dont find it and
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* thus cannot deallocate
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*/
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rval = 1;
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for (i = 0; i < curr_pmm_allocation_index; i++) {
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DEBUG_PRINTF_PMM("%d: %x\n", i,
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pmm_allocation_array[i].handle);
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if (pmm_allocation_array[i].offset == buffer) {
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/* we found the requested buffer, rval = 0 */
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rval = 0;
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DEBUG_PRINTF_PMM
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("%s: pmmDeallocate: found allocated memory at index: %d\n",
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__func__, i);
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/* copy the remaining elements in pmm_allocation_array one position up */
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j = i;
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for (; j < curr_pmm_allocation_index; j++) {
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pmm_allocation_array[j] =
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pmm_allocation_array[j + 1];
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}
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/* move curr_pmm_allocation_index one up, too */
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curr_pmm_allocation_index--;
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/* finally clean last element */
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pmm_allocation_array[curr_pmm_allocation_index].
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handle = 0;
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pmm_allocation_array[curr_pmm_allocation_index].
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offset = 0;
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pmm_allocation_array[curr_pmm_allocation_index].
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length = 0;
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break;
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}
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}
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if (rval != 0) {
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DEBUG_PRINTF_PMM
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("%s: pmmDeallocate: offset (%x) not found, cannot deallocate!\n",
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__func__, buffer);
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}
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goto exit;
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default:
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/* invalid/unimplemented function */
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printf("%s: invalid PMM function (0x%04x) called!\n",
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__func__, function);
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/* PMM spec says if function is invalid, return 0xFFFFFFFF */
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rval = 0xFFFFFFFF;
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goto exit;
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}
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exit:
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/* exit handler of this function, restore registers, put return value in DX:AX */
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M.x86 = backup_regs;
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M.x86.R_DX = (u16) ((rval >> 16) & 0xFFFF);
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M.x86.R_AX = (u16) (rval & 0xFFFF);
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CHECK_DBG(DEBUG_PMM) {
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DEBUG_PRINTF_PMM("%s: dump of pmm_allocation_array:\n",
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__func__);
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for (i = 0; i < MAX_PMM_AREAS; i++) {
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DEBUG_PRINTF_PMM
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("%d:\n\thandle: %x\n\toffset: %x\n\tlength: %x\n",
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i, pmm_allocation_array[i].handle,
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pmm_allocation_array[i].offset,
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pmm_allocation_array[i].length);
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}
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}
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return;
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}
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/* This function tests the pmm_handleInt() function above. */
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void pmm_test(void)
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{
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u32 handle, length, addr;
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u16 function, flags;
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/*-------------------- Test simple allocation/find/deallocation ----------------------------- */
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function = 0; /* pmmAllocate */
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handle = 0xdeadbeef;
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length = 16; /* in 16byte paragraphs, so we allocate 256 bytes... */
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flags = 0x1; /* conventional memory, unaligned */
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/* setup stack for call to pmm_handleInt() */
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push_word(flags);
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push_long(handle);
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push_long(length);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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addr = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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DEBUG_PRINTF_PMM("%s: allocated memory at: %04x:%04x\n", __func__,
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M.x86.R_DX, M.x86.R_AX);
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function = 1; /* pmmFind */
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push_long(handle);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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DEBUG_PRINTF_PMM("%s: found memory at: %04x:%04x (expected: %08x)\n",
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__func__, M.x86.R_DX, M.x86.R_AX, addr);
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function = 2; /* pmmDeallocate */
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push_long(addr);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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DEBUG_PRINTF_PMM
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("%s: freed memory rval: %04x:%04x (expected: 0000:0000)\n",
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__func__, M.x86.R_DX, M.x86.R_AX);
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/*-------------------- Test aligned allocation/deallocation ----------------------------- */
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function = 0; /* pmmAllocate */
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handle = 0xdeadbeef;
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length = 257; /* in 16byte paragraphs, so we allocate 4KB + 16 bytes... */
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flags = 0x1; /* conventional memory, unaligned */
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/* setup stack for call to pmm_handleInt() */
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push_word(flags);
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push_long(handle);
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push_long(length);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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addr = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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DEBUG_PRINTF_PMM("%s: allocated memory at: %04x:%04x\n", __func__,
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M.x86.R_DX, M.x86.R_AX);
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function = 0; /* pmmAllocate */
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handle = 0xf00d4b0b;
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length = 128; /* in 16byte paragraphs, so we allocate 2KB... */
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flags = 0x5; /* conventional memory, aligned */
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/* setup stack for call to pmm_handleInt() */
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push_word(flags);
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push_long(handle);
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push_long(length);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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/* the address should be aligned to 0x800, so probably it is at offset 0x1800... */
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addr = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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DEBUG_PRINTF_PMM("%s: allocated memory at: %04x:%04x\n", __func__,
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M.x86.R_DX, M.x86.R_AX);
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function = 1; /* pmmFind */
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push_long(handle);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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addr = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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function = 2; /* pmmDeallocate */
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push_long(addr);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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DEBUG_PRINTF_PMM
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("%s: freed memory rval: %04x:%04x (expected: 0000:0000)\n",
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__func__, M.x86.R_DX, M.x86.R_AX);
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handle = 0xdeadbeef;
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function = 1; /* pmmFind */
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push_long(handle);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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addr = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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function = 2; /* pmmDeallocate */
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push_long(addr);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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DEBUG_PRINTF_PMM
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("%s: freed memory rval: %04x:%04x (expected: 0000:0000)\n",
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__func__, M.x86.R_DX, M.x86.R_AX);
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/*-------------------- Test out of memory allocation ----------------------------- */
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function = 0; /* pmmAllocate */
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handle = 0xdeadbeef;
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length = 0; /* length zero means, give me the largest possible block */
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flags = 0x1; /* conventional memory, unaligned */
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/* setup stack for call to pmm_handleInt() */
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push_word(flags);
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push_long(handle);
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push_long(length);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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length = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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length /= 16; /* length in paragraphs */
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DEBUG_PRINTF_PMM("%s: largest possible length: %08x\n", __func__,
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length);
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function = 0; /* pmmAllocate */
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flags = 0x1; /* conventional memory, aligned */
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/* setup stack for call to pmm_handleInt() */
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push_word(flags);
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push_long(handle);
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push_long(length);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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addr = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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DEBUG_PRINTF_PMM("%s: allocated memory at: %04x:%04x\n", __func__,
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M.x86.R_DX, M.x86.R_AX);
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function = 0; /* pmmAllocate */
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length = 1;
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handle = 0xf00d4b0b;
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flags = 0x1; /* conventional memory, aligned */
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/* setup stack for call to pmm_handleInt() */
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push_word(flags);
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push_long(handle);
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push_long(length);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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/* this should fail, so 0x0 should be returned */
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addr = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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DEBUG_PRINTF_PMM
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("%s: allocated memory at: %04x:%04x expected: 0000:0000\n",
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__func__, M.x86.R_DX, M.x86.R_AX);
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handle = 0xdeadbeef;
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function = 1; /* pmmFind */
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push_long(handle);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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addr = ((u32) M.x86.R_DX << 16) | M.x86.R_AX;
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function = 2; /* pmmDeallocate */
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push_long(addr);
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push_word(function);
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push_long(0); /* This is the return address for the ABI, unused in this implementation */
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pmm_handleInt();
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DEBUG_PRINTF_PMM
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("%s: freed memory rval: %04x:%04x (expected: 0000:0000)\n",
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__func__, M.x86.R_DX, M.x86.R_AX);
|
|
}
|