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Add support for loading IBM ROM BASIC from a file and including it in the ROM BIOS region

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This commit is contained in:
Jonathan Campbell 2021-11-04 00:21:51 -07:00
parent 8a81088b25
commit 677a5a10d3
3 changed files with 50 additions and 16 deletions
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BIN
ROMs/IBMROMBASIC-F6000h-1982-10-27.ROM Normal file
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4
src/dosbox.cpp
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@ -1575,6 +1575,10 @@ void DOSBOX_SetupConfigSections(void) {
Pstring->Set_help("If set, this is the path of a binary blob to load into the ROM BIOS area and execute immediately before booting the DOS system.\n"
"This can be used for x86 assembly language experiments and automated testing against the CPU emulation.");
Pstring = secprop->Add_string("ibm rom basic",Property::Changeable::WhenIdle,"");
Pstring->Set_help("If set, this is the path of a ROM image containing IBM ROM BASIC. This is loaded just below the ROM BIOS.\n"
"One recommended file is IBMROMBASIC-F6000h-1982-10-27.ROM, a 32KB ROM BIOS image loaded to segment F600 taken from an IBM 5150.\n");
Pint = secprop->Add_int("rom bios allocation max",Property::Changeable::OnlyAtStart,0);
Pint->SetMinMax(0,128);
Pint->Set_help("Maximum size (top down from 1MB) allowed for ROM BIOS dynamic allocation in KB");

62
src/ints/bios.cpp
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@ -72,6 +72,10 @@ extern bool PS1AudioCard;
# define S_ISREG(x) ((x & S_IFREG) == S_IFREG)
#endif
std::string ibm_rom_basic;
size_t ibm_rom_basic_size = 0;
uint32_t ibm_rom_basic_base = 0;
/* NTS: The "Epson check" code in Windows 2.1 only compares up to the end of "NEC Corporation" */
const std::string pc98_copyright_str = "Copyright (C) 1983 by NEC Corporation / Microsoft Corp.\x0D\x0A";
@ -9727,30 +9731,32 @@ public:
phys_writeb(bo+0x05,0xFE);
}
else {
/* IBM MS-DOS 1.x/2.x BASIC and BASICA, stopgap */
PhysPt bo;
if (ibm_rom_basic_size == 0) {
/* IBM MS-DOS 1.x/2.x BASIC and BASICA, stopgap */
PhysPt bo;
bo = 0xF6000+0x2DB0; // F600:2DB0
bo = 0xF6000+0x2DB0; // F600:2DB0
ROMBIOS_GetMemory(6,"IBM ROM BASIC entry point",/*align*/1,bo);
ROMBIOS_GetMemory(6,"IBM ROM BASIC entry point",/*align*/1,bo);
phys_writeb(bo+0x00,(uint8_t)0xFE); //GRP 4
phys_writeb(bo+0x01,(uint8_t)0x38); //Extra Callback instruction
phys_writew(bo+0x02,(uint16_t)cb_ibm_basic.Get_callback()); //The immediate word
phys_writeb(bo+0x00,(uint8_t)0xFE); //GRP 4
phys_writeb(bo+0x01,(uint8_t)0x38); //Extra Callback instruction
phys_writew(bo+0x02,(uint16_t)cb_ibm_basic.Get_callback()); //The immediate word
phys_writeb(bo+0x04,0xEB); // JMP $-2
phys_writeb(bo+0x05,0xFE);
phys_writeb(bo+0x04,0xEB); // JMP $-2
phys_writeb(bo+0x05,0xFE);
bo = 0xF6000+0x4C79; // F600:4C79
bo = 0xF6000+0x4C79; // F600:4C79
ROMBIOS_GetMemory(6,"IBM ROM BASIC entry point",/*align*/1,bo);
ROMBIOS_GetMemory(6,"IBM ROM BASIC entry point",/*align*/1,bo);
phys_writeb(bo+0x00,(uint8_t)0xFE); //GRP 4
phys_writeb(bo+0x01,(uint8_t)0x38); //Extra Callback instruction
phys_writew(bo+0x02,(uint16_t)cb_ibm_basic.Get_callback()); //The immediate word
phys_writeb(bo+0x00,(uint8_t)0xFE); //GRP 4
phys_writeb(bo+0x01,(uint8_t)0x38); //Extra Callback instruction
phys_writew(bo+0x02,(uint16_t)cb_ibm_basic.Get_callback()); //The immediate word
phys_writeb(bo+0x04,0xEB); // JMP $-2
phys_writeb(bo+0x05,0xFE);
phys_writeb(bo+0x04,0xEB); // JMP $-2
phys_writeb(bo+0x05,0xFE);
}
}
if (IS_PC98_ARCH && enable_pc98_copyright_string) {
@ -10059,6 +10065,9 @@ void ROMBIOS_Init() {
// log
LOG(LOG_MISC,LOG_DEBUG)("Initializing ROM BIOS");
ibm_rom_basic.clear();
ibm_rom_basic_size = 0;
oi = (Bitu)section->Get_int("rom bios minimum size"); /* in KB */
oi = (oi + 3u) & ~3u; /* round to 4KB page */
if (oi > 128u) oi = 128u;
@ -10132,6 +10141,27 @@ void ROMBIOS_Init() {
rombios_alloc.setMaxDynamicAllocationAddress(0xFE000 - 1);
}
if (!IS_PC98_ARCH) {
ibm_rom_basic = section->Get_string("ibm rom basic");
if (!ibm_rom_basic.empty()) {
struct stat st;
if (stat(ibm_rom_basic.c_str(),&st) == 0 && S_ISREG(st.st_mode) && st.st_size >= (off_t)(32u*1024u) && st.st_size <= (off_t)(64u*1024u) && (st.st_size % 4096) == 0) {
ibm_rom_basic_size = (size_t)st.st_size;
ibm_rom_basic_base = rombios_alloc._max_nonfixed + 1 - st.st_size;
LOG_MSG("Will load IBM ROM BASIC to %05lx-%05lx",(unsigned long)ibm_rom_basic_base,(unsigned long)(ibm_rom_basic_base+ibm_rom_basic_size-1));
Bitu base = ROMBIOS_GetMemory(ibm_rom_basic_size,"IBM ROM BASIC",1u/*page align*/,ibm_rom_basic_base);
rombios_alloc.setMaxDynamicAllocationAddress(ibm_rom_basic_base - 1);
FILE *fp = fopen(ibm_rom_basic.c_str(),"rb");
if (fp != NULL) {
fread(GetMemBase()+ibm_rom_basic_base,(size_t)ibm_rom_basic_size,1u,fp);
fclose(fp);
}
}
}
}
write_ID_version_string();
if (IS_PC98_ARCH && enable_pc98_copyright_string) { // PC-98 BIOSes have a copyright string at E800:0DD8