From ca5128008df77599a6a993caa550e0502d95ef8d Mon Sep 17 00:00:00 2001 From: Javier Date: Wed, 6 Apr 2022 02:44:24 +0200 Subject: implement autoinstallation to upper memory --- dosmain.c | 183 +++++++++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 158 insertions(+), 25 deletions(-) (limited to 'dosmain.c') diff --git a/dosmain.c b/dosmain.c index 0ac5f75..5e789a9 100644 --- a/dosmain.c +++ b/dosmain.c @@ -25,6 +25,7 @@ #include "dlog.h" #include "int33.h" +#include "int21dos.h" #include "ps2.h" #include "vbox.h" #include "vmware.h" @@ -241,34 +242,142 @@ static int configure_driver(LPTSRDATA data) return 0; } -static void deallocate_environment(uint16_t psp) +/** Converts bytes to MS-DOS "paragraphs" (16 bytes), rounding up. */ +static inline unsigned get_paragraphs(unsigned bytes) +{ + return (bytes + 15) / 16; +} + +/** Gets the size of the resident part of this program, including the PSP. */ +static inline unsigned get_resident_program_size() +{ + return get_resident_size() + DOS_PSP_SIZE; +} + +/** Deallocates the environment block from the passed PSP segment. */ +static void deallocate_environment(__segment psp) { // TODO : Too lazy to make PSP struct; // 0x2C is offsetof the environment block field on the PSP uint16_t __far *envblockP = (uint16_t __far *) MK_FP(psp, 0x2C); - _dos_freemem(*envblockP); + dos_free(*envblockP); *envblockP = 0; } -static int install_driver(LPTSRDATA data) +/** Copies a program to another location. + * @param new_seg PSP segment for the new location + * @param old_seg PSP segment for the old location + * @param size size of the program to copy including PSP size. */ +static void copy_program(__segment new_seg, __segment old_seg, unsigned size) +{ + // The MCB is always 1 segment before. + uint8_t __far *new_mcb = MK_FP(new_seg - 1, 0); + uint8_t __far *old_mcb = MK_FP(old_seg - 1, 0); + uint16_t __far *new_mcb_owner = (uint16_t __far *) &new_mcb[1]; + char __far *new_mcb_owner_name = &new_mcb[8]; + char __far *old_mcb_owner_name = &old_mcb[8]; + + // Copy entire resident segment including PSP + _fmemcpy(MK_FP(new_seg, 0), MK_FP(old_seg, 0), size); + + // Make the new MCB point to itself as owner + *new_mcb_owner = new_seg; + + // Copy the program name, too. + _fmemcpy(new_mcb_owner_name, old_mcb_owner_name, 8); +} + +/** Allocates a UMB of the given size. + * If no UMBs are available, this may still return a block in conventional memory. */ +static __segment allocate_umb(unsigned size) +{ + bool old_umb_link = dos_query_umb_link_state(); + unsigned int old_strategy = dos_query_allocation_strategy(); + __segment new_segment; + + dos_set_umb_link_state(true); + dos_set_allocation_strategy(DOS_FIT_BEST | DOS_FIT_HIGHONLY); + + new_segment = dos_alloc(get_paragraphs(size)); + + dos_set_umb_link_state(old_umb_link); + dos_set_allocation_strategy(old_strategy); + + return new_segment; +} + +static int reallocate_to_umb(LPTSRDATA __far * data) { - unsigned int resident_size = get_resident_size(); + const unsigned int resident_size = get_resident_program_size(); + LPTSRDATA old_data = *data; + __segment old_psp_segment = FP_SEG(old_data) - (DOS_PSP_SIZE/16); + __segment new_psp_segment; - // Not that this will do anything other than fragment memory, but why not... deallocate_environment(_psp); + // If we are already in UMA, don't bother + if (old_psp_segment >= 0xA000) { + return -1; + } + + new_psp_segment = allocate_umb(resident_size); + + if (new_psp_segment && new_psp_segment >= 0xA000) { + __segment new_segment = new_psp_segment + (DOS_PSP_SIZE/16); + printf("Moving to upper memory\n"); + + // Create a new program instance including PSP at the new_segment + copy_program(new_psp_segment, old_psp_segment, resident_size); + + // Tell DOS to "switch" to the new program + dos_set_psp(new_psp_segment); + + // Now update the data pointer to the new segment + *data = MK_FP(new_segment, FP_OFF(old_data)); + + return 0; + } else { + printf("No upper memory available\n"); + if (new_psp_segment) { + // In case we got another low-memory segment... + dos_free(new_psp_segment); + } + + return -1; + } +} + +static __declspec(aborts) int install_driver(LPTSRDATA data, bool high) +{ + const unsigned int resident_size = DOS_PSP_SIZE + get_resident_size(); + + // No more interruptions from now on and until we TSR. + // Inserting ourselves in the interrupt chain should be atomic. + _disable(); + data->prev_int33_handler = _dos_getvect(0x33); - _dos_setvect(0x33, int33_isr); + _dos_setvect(0x33, data:>int33_isr); #if USE_WIN386 data->prev_int2f_handler = _dos_getvect(0x2f); - _dos_setvect(0x2f, int2f_isr); + _dos_setvect(0x2f, data:>int2f_isr); #endif printf("Driver installed\n"); - _dos_keep(EXIT_SUCCESS, (256 + resident_size + 15) / 16); - return 0; + // If we reallocated ourselves to UMB, + // it's time to free our initial conventional memory allocation + if (high) { + // We are about to free() our own code segment. + // Nothing should try to allocate memory between this and the TSR call + // below, since it could overwrite our code... + dos_free(_psp); + } + + _dos_keep(EXIT_SUCCESS, get_paragraphs(resident_size)); + + // Shouldn't reach this part + return EXIT_FAILURE; } static bool check_if_driver_uninstallable(LPTSRDATA data) @@ -298,10 +407,8 @@ static bool check_if_driver_uninstallable(LPTSRDATA data) static int unconfigure_driver(LPTSRDATA data) { -#if USE_VIRTUALBOX - if (data->vbavail) { - set_integration(data, false); - } +#if USE_INTEGRATION + set_integration(data, false); #endif ps2m_enable(false); @@ -320,7 +427,7 @@ static int uninstall_driver(LPTSRDATA data) // Find and deallocate the PSP (including the entire program), // it is always 256 bytes (16 paragraphs) before the TSR segment - _dos_freemem(FP_SEG(data) - 16); + dos_free(FP_SEG(data) - (DOS_PSP_SIZE/16)); printf("Driver uninstalled\n"); @@ -343,21 +450,29 @@ static void print_help(void) { printf("\n" "Usage: \n" - "\tVBMOUSE \n\n" + " VBMOUSE \n\n" "Supported actions:\n" - "\tinstall install the driver (default)\n" - "\tuninstall uninstall the driver from memory\n" + " install install the driver (default)\n" + " low install in conventional memory (otherwise UMB)\n" + " uninstall uninstall the driver from memory\n" #if USE_WHEEL - "\twheel enable/disable wheel API support\n" + " wheel enable/disable wheel API support\n" #endif #if USE_INTEGRATION - "\tinteg enable/disable virtualbox integration\n" - "\thostcur enable/disable mouse cursor rendering in host\n" + " integ enable/disable virtualbox integration\n" + " hostcur enable/disable mouse cursor rendering in host\n" #endif - "\treset reset mouse driver settings\n" + " reset reset mouse driver settings\n" ); } +static int invalid_arg(const char *s) +{ + fprintf(stderr, "Invalid argument '%s'", s); + print_help(); + return EXIT_FAILURE; +} + static bool is_true(const char *s) { return stricmp(s, "yes") == 0 @@ -388,15 +503,34 @@ int main(int argc, const char *argv[]) printf("\nVBMouse %x.%x (like MSMOUSE %x.%x)\n", VERSION_MAJOR, VERSION_MINOR, REPORTED_VERSION_MAJOR, REPORTED_VERSION_MINOR); if (argi >= argc || stricmp(argv[argi], "install") == 0) { + bool high = true; + + argi++; + for (; argi < argc; argi++) { + if (stricmp(argv[argi], "low") == 0) { + high = false; + } else if (stricmp(argv[argi], "high") == 0) { + high = true; + } else { + return invalid_arg(argv[argi]); + } + } + if (data) { printf("VBMouse already installed\n"); return EXIT_SUCCESS; } data = get_tsr_data(false); + if (high) { + err = reallocate_to_umb(&data); + if (err) high = false; // Not fatal + } else { + deallocate_environment(_psp); + } err = configure_driver(data); if (err) return EXIT_FAILURE; - return install_driver(data); + return install_driver(data, high); } else if (stricmp(argv[argi], "uninstall") == 0) { if (!data) return driver_not_found(); if (!check_if_driver_uninstallable(data)) { @@ -449,8 +583,7 @@ int main(int argc, const char *argv[]) #endif } else if (stricmp(argv[argi], "reset") == 0) { return driver_reset(); + } else { + return invalid_arg(argv[argi]); } - - print_help(); - return EXIT_FAILURE; } -- cgit v1.2.3