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mirror of https://github.com/pevans/erc-c.git synced 2024-12-13 15:33:17 +00:00

Add display buffer read/write mappers

This commit is contained in:
Peter Evans 2018-01-13 15:40:40 -06:00
parent 45eb7b5e58
commit cadc19b3e5
5 changed files with 170 additions and 1 deletions

11
include/apple2.dbuf.h Normal file
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@ -0,0 +1,11 @@
#ifndef _APPLE2_DBUF_H_
#define _APPLE2_DBUF_H_
#include "apple2.h"
#include "vm_segment.h"
extern SEGMENT_READER(apple2_dbuf_read);
extern SEGMENT_WRITER(apple2_dbuf_write);
extern void apple2_dbuf_map(vm_segment *);
#endif

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@ -1,6 +1,7 @@
set(erc_sources
apple2.c
apple2.bank.c
apple2.dbuf.c
apple2.dd.c
apple2.draw.c
apple2.mem.c

84
src/apple2.dbuf.c Normal file
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/*
* apple2.dbuf.c
*/
#include "apple2.dbuf.h"
/*
* Handle reads from text page 1 and hires graphics page 1 (the display
* buffers).
*/
SEGMENT_READER(apple2_dbuf_read)
{
apple2 *mach = (apple2 *)_mach;
// When 80STORE is high, we are allowed to look into two other flags
// to see if they are set and modify our behavior accordingly.
if (mach->memory_mode & MEMORY_80STORE) {
// If the address is contained within text page 1, then we need
// to look up memory in aux. (Uh, don't ask why we switch page 1
// with the PAGE2 flag.) Otherwise, if the address is contained
// in hires graphics page 1, then that must also use aux memory
// if _both_ the PAGE2 and HIRES bits are set.
if (addr >= 0x400 && addr < 0x800 &&
mach->memory_mode & MEMORY_PAGE2
) {
segment = mach->aux;
} else if (addr >= 0x2000 && addr < 0x4000 &&
mach->memory_mode & MEMORY_PAGE2 & MEMORY_HIRES
) {
segment = mach->aux;
}
}
// In all other cases, we _must_ use the segment that was passed in.
// That segment may be aux memory if MEMORY_READ_AUX is set, and if
// so, that would be the desired behavior.
return segment->memory[addr];
}
/*
* Many of the cautions and notes in the apple2_dbuf_read function
* apply here as well.
*/
SEGMENT_WRITER(apple2_dbuf_write)
{
apple2 *mach = (apple2 *)_mach;
if (mach->memory_mode & MEMORY_80STORE) {
if (addr >= 0x400 && addr < 0x800 &&
mach->memory_mode & MEMORY_PAGE2
) {
segment = mach->aux;
} else if (addr >= 0x2000 && addr < 0x4000 &&
mach->memory_mode & MEMORY_PAGE2 &&
mach->memory_mode & MEMORY_HIRES
) {
segment = mach->aux;
}
}
// Again, segment is allowed to be that which was passed in if
// 80STORE is low.
segment->memory[addr] = value;
}
/*
* Map the text page 1 and hires graphics page 1 addresses to the dbuf
* read and write functions.
*/
void
apple2_dbuf_map(vm_segment *segment)
{
size_t addr;
for (addr = 0x400; addr < 0x800; addr++) {
vm_segment_read_map(segment, addr, apple2_dbuf_read);
vm_segment_write_map(segment, addr, apple2_dbuf_write);
}
for (addr = 0x2000; addr < 0x4000; addr++) {
vm_segment_read_map(segment, addr, apple2_dbuf_read);
vm_segment_write_map(segment, addr, apple2_dbuf_write);
}
}

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@ -2,9 +2,10 @@
* apple2.mem.c
*/
#include "apple2.bank.h"
#include "apple2.dbuf.h"
#include "apple2.h"
#include "apple2.mem.h"
#include "apple2.bank.h"
#include "objstore.h"
/*
@ -21,6 +22,9 @@ apple2_mem_map(apple2 *mach, vm_segment *segment)
// of it.
apple2_bank_map(segment);
// Here we handle the 80STORE bit for our display buffers.
apple2_dbuf_map(segment);
// We will do the mapping for the zero page and stack addresses.
// Accessing those addresses can be affected by bank-switching, but
// those addresses do not actually exist in the capital

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tests/apple2.dbuf.c Normal file
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#include <criterion/criterion.h>
#include "apple2.h"
#include "apple2.dbuf.h"
#include "vm_segment.h"
static apple2 *mach = NULL;
static void
setup()
{
mach = apple2_create(100, 100);
vm_segment_set_map_machine(mach);
}
static void
teardown()
{
apple2_free(mach);
vm_segment_set_map_machine(NULL);
}
TestSuite(apple2_dbuf, .init = setup, .fini = teardown);
Test(apple2_dbuf, map)
{
size_t addr;
int i;
vm_segment *segments[2];
segments[0] = mach->main;
segments[1] = mach->aux;
for (i = 0; i < 2; i++) {
for (addr = 0x400; addr < 0x800; addr++) {
cr_assert_eq(segments[i]->read_table[addr], apple2_dbuf_read);
cr_assert_eq(segments[i]->write_table[addr], apple2_dbuf_write);
}
for (addr = 0x2000; addr < 0x4000; addr++) {
cr_assert_eq(segments[i]->read_table[addr], apple2_dbuf_read);
cr_assert_eq(segments[i]->write_table[addr], apple2_dbuf_write);
}
}
}
/*
* This test also works on apple2_dbuf_write.
*
* Test(apple2_dbuf, write)
*/
Test(apple2_dbuf, read)
{
apple2_set_memory_mode(mach, MEMORY_80STORE | MEMORY_PAGE2);
vm_segment_set(mach->main, 0x400, 123);
vm_segment_set(mach->main, 0x2000, 234);
cr_assert_neq(mach->main->memory[0x400], 123);
cr_assert_eq(mach->aux->memory[0x400], 123);
cr_assert_eq(mach->main->memory[0x2000], 234);
cr_assert_neq(mach->aux->memory[0x2000], 234);
apple2_set_memory_mode(mach, MEMORY_80STORE | MEMORY_PAGE2 | MEMORY_HIRES);
vm_segment_set(mach->main, 0x2000, 234);
cr_assert_eq(mach->main->memory[0x2000], 234);
cr_assert_eq(mach->aux->memory[0x2000], 234);
}
Test(apple2_dbuf, write)
{
}