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Reworked the memory code a bit to avoid crashes while switching machine/processor types.

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This commit is contained in:
waltje
2018-03-18 18:39:02 -05:00
parent cda21661b1
commit d40526144c
2 changed files with 88 additions and 40 deletions
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124
src/mem.c
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@@ -8,7 +8,11 @@
*
* Memory handling and MMU.
*
* Version: @(#)mem.c 1.0.7 2018/03/17
* NOTE: Experimenting with dynamically allocated lookup tables;
* the DYNAMIC_TABLES=1 enables this. Will eventually go
* away, either way...
*
* Version: @(#)mem.c 1.0.8 2018/03/18
*
* Authors: Fred N. van Kempen, <decwiz@yahoo.com>
* Miran Grca, <mgrca8@gmail.com>
@@ -61,6 +65,9 @@
#endif
#define DYNAMIC_TABLES 0 /* experimental */
mem_mapping_t ram_low_mapping;
mem_mapping_t ram_high_mapping;
mem_mapping_t ram_mid_mapping;
@@ -135,7 +142,7 @@ static mem_mapping_t base_mapping;
static mem_mapping_t ram_remapped_mapping;
static mem_mapping_t ram_split_mapping;
#if 0
#if FIXME
static uint8_t ff_array[0x1000];
#else
static uint8_t ff_pccache[4] = { 0xff, 0xff, 0xff, 0xff };
@@ -150,20 +157,34 @@ resetreadlookup(void)
int c;
/* This is NULL after app startup, when mem_init() has not yet run. */
if (page_lookup == NULL) return;
#if DYNAMIC_TABLES
pclog("MEM: reset_lookup: pages=%08lx, lookup=%08lx, pages_sz=%i\n", pages, page_lookup, pages_sz);
#endif
memset(page_lookup, 0x00, pages_sz * sizeof(page_t *));
/* Initialize the page lookup table. */
#if DYNAMIC_TABLES
memset(page_lookup, 0x00, pages_sz*sizeof(page_t *));
#else
memset(page_lookup, 0x00, (1<<20)*sizeof(page_t *));
#endif
for (c = 0; c < 256; c++)
/* Initialize the tables for lower (<= 1024K) RAM. */
for (c = 0; c < 256; c++) {
readlookup[c] = 0xffffffff;
memset(readlookup2, 0xff, pages_sz*sizeof(uintptr_t));
readlnext = 0;
for (c = 0; c < 256; c++)
writelookup[c] = 0xffffffff;
memset(writelookup2, 0xff, pages_sz*sizeof(uintptr_t));
writelnext = 0;
}
/* Initialize the tables for high (> 1024K) RAM. */
#if DYNAMIC_TABLES
memset(readlookup2, 0xff, pages_sz*sizeof(uintptr_t));
memset(writelookup2, 0xff, pages_sz*sizeof(uintptr_t));
#else
memset(readlookup2, 0xff, (1<<20)*sizeof(uintptr_t));
memset(writelookup2, 0xff, (1<<20)*sizeof(uintptr_t));
#endif
readlnext = 0;
writelnext = 0;
pccache = 0xffffffff;
}
@@ -1544,15 +1565,11 @@ mem_reset(void)
uint32_t c, m;
split_mapping_enabled = 0;
/* Free existing memory and tables. */
if (ram != NULL) free(ram);
if (rom != NULL) free(rom);
if (pages != NULL) free(pages);
if (page_lookup != NULL) free(page_lookup);
if (readlookup2 != NULL) free(readlookup2);
if (writelookup2 != NULL) free(writelookup2);
/* Free the ROM memory and reset size mask. */
if (rom != NULL) {
free(rom);
rom = NULL;
}
biosmask = 0xffff;
@@ -1564,7 +1581,8 @@ mem_reset(void)
if (mem_size < 16384)
m = 1024UL * 16384;
else
m = 1024UL * (mem_size + 384); /* 386 extra kB for top remapping */
m = 1024UL * (mem_size + 384); /* 386 extra kB for top remapping */
if (ram != NULL) free(ram);
ram = (uint8_t *)malloc(m); /* allocate and clear the RAM block */
memset(ram, 0x00, m);
@@ -1589,23 +1607,43 @@ mem_reset(void)
/* 8088/86; maximum address space is 1MB. */
m = 256;
}
pages_sz = m;
pages = (page_t *)malloc(m * sizeof(page_t));
memset(pages, 0x00, m * sizeof(page_t));
for (c=0; c<m; c++) {
pages[c].mem = &ram[c << 12];
pages[c].write_b = mem_write_ramb_page;
pages[c].write_w = mem_write_ramw_page;
pages[c].write_l = mem_write_raml_page;
}
/*
* Allocate and initialize the (new) page table.
* We only do this if the size of the page table has changed.
*/
#if DYNAMIC_TABLES
pclog("MEM: reset: previous pages=%08lx, pages_sz=%i\n", pages, pages_sz);
#endif
if (pages_sz != m) {
pages_sz = m;
free(pages);
pages = (page_t *)malloc(m*sizeof(page_t));
memset(pages, 0x00, m*sizeof(page_t));
#if DYNAMIC_TABLES
pclog("MEM: reset: new pages=%08lx, pages_sz=%i\n", pages, pages_sz);
#endif
for (c=0; c<m; c++) {
pages[c].mem = &ram[c << 12];
pages[c].write_b = mem_write_ramb_page;
pages[c].write_w = mem_write_ramw_page;
pages[c].write_l = mem_write_raml_page;
memset(page_lookup, 0x00, pages_sz * sizeof(page_t *));
/* Allocate and initialize the lookup tables. */
readlookup2 = malloc(pages_sz * sizeof(uintptr_t));
memset(readlookup2, 0xff, pages_sz * sizeof(page_t *));
}
#if DYNAMIC_TABLES
/* Allocate the (new) lookup tables. */
if (page_lookup != NULL) free(page_lookup);
page_lookup = (page_t **)malloc(pages_sz*sizeof(page_t *));
if (readlookup2 != NULL) free(readlookup2);
readlookup2 = malloc(pages_sz*sizeof(uintptr_t));
if (writelookup2 != NULL) free(writelookup2);
writelookup2 = malloc(pages_sz*sizeof(uintptr_t));
#endif
}
/* Initialize the tables. */
resetreadlookup();
@@ -1691,13 +1729,23 @@ mem_init(void)
mem_init(void)
{
/* Perform a one-time init. */
ram = rom = NULL;
pages = NULL;
#if DYNAMIC_TABLES
page_lookup = NULL;
readlookup2 = NULL;
writelookup2 = NULL;
#else
/* Allocate the lookup tables. */
page_lookup = (page_t **)malloc((1<<20)*sizeof(page_t *));
readlookup2 = malloc((1<<20)*sizeof(uintptr_t));
writelookup2 = malloc((1<<20)*sizeof(uintptr_t));
#endif
memset(ram_mapped_addr, 0x00, 64 * sizeof(uint32_t));
memset(ram_mapped_addr, 0x00, 64 * sizeof(uint32_t));
#if FIXME
memset(ff_array, 0xff, sizeof(ff_array));