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Diffstat (limited to 'int15ps2.h')
| -rw-r--r-- | int15ps2.h | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/int15ps2.h b/int15ps2.h new file mode 100644 index 0000000..6b6c415 --- /dev/null +++ b/int15ps2.h @@ -0,0 +1,235 @@ +/* + * VBMouse - Routines to access the PS2 BIOS services + * Copyright (C) 2022 Javier S. Pedro + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#ifndef INT15PS2_H +#define INT15PS2_H + +#include <stdbool.h> +#include <stdint.h> + +/** Standard PS/2 mouse IRQ. At least on VirtualBox. */ +#define PS2_MOUSE_IRQ 12 +/** The corresponding interrupt vector for IRQ 12. */ +#define PS2_MOUSE_INT_VECTOR 0x74 + +typedef uint8_t ps2m_err; +enum ps2m_errors { + PS2M_ERR_INVALID_FUNCTION = 1, + PSM2_ERR_INVALID_INPUT = 2, + PSM2_ERR_INTERFACE_ERROR = 3, + PSM2_ERR_RESEND = 4, + PSM2_ERR_NO_CALLBACK = 5, +}; + +enum ps2m_status { + PS2M_STATUS_BUTTON_1 = 1 << 0, + PS2M_STATUS_BUTTON_2 = 1 << 1, + PS2M_STATUS_BUTTON_3 = 1 << 2, + PS2M_STATUS_X_NEG = 1 << 4, + PS2M_STATUS_Y_NEG = 1 << 5, + PS2M_STATUS_X_OVF = 1 << 6, + PS2M_STATUS_Y_OVF = 1 << 7, +}; + +enum ps2m_packet_size { + PS2M_PACKET_SIZE_PLAIN = 3, + PS2M_PACKET_SIZE_EXT = 4, +}; + +enum ps2m_device_ids { + /** Standard PS/2 mouse, 2 buttons. */ + PS2M_DEVICE_ID_PLAIN = 0, + /** IntelliMouse PS/2, with wheel. */ + PS2M_DEVICE_ID_IMPS2 = 3, + /** IntelliMouse Explorer, wheel and 5 buttons. */ + PS2M_DEVICE_ID_IMEX = 4, + /** IntelliMouse Explorer, wheel, 5 buttons, and horizontal scrolling. */ + PS2M_DEVICE_ID_IMEX_HORZ = 5 +}; + +enum ps2m_resolution { + PS2M_RESOLUTION_25 = 0, + PS2M_RESOLUTION_50 = 1, + PS2M_RESOLUTION_100 = 2, + PS2M_RESOLUTION_200 = 3 +}; + +enum ps2m_sample_rate { + PS2M_SAMPLE_RATE_10 = 0, + PS2M_SAMPLE_RATE_20 = 1, + PS2M_SAMPLE_RATE_40 = 2, + PS2M_SAMPLE_RATE_60 = 3, + PS2M_SAMPLE_RATE_80 = 4, + PS2M_SAMPLE_RATE_100 = 5, + PS2M_SAMPLE_RATE_200 = 6 +}; + +/** Invoked by the BIOS when there is a mouse event. */ +typedef void (__far * LPFN_PS2CALLBACK)(); + +static ps2m_err ps2m_init(uint8_t packet_size); +#pragma aux ps2m_init = \ + "stc" /* If nothing happens, assume failure */ \ + "mov ax, 0xC205" /* Pointing device: initialization (packet size in bh) */ \ + "int 0x15" \ + "jnc end" /* Success */ \ + "fail: test ah, ah" /* Ensure we have some error code back, set ah to -1 if we don't */ \ + "jnz end" \ + "dec ah" \ + "end:" \ + __parm [bh] \ + __value [ah] \ + __modify [ax] + +static ps2m_err ps2m_reset(void); +#pragma aux ps2m_reset = \ + "stc" \ + "mov ax, 0xC201" /* Pointing device: reset */ \ + "int 0x15" \ + "jnc end" \ + "fail: test ah, ah" \ + "jnz end" \ + "dec ah" \ + "end:" \ + __value [ah] \ + __modify [ax] + +static ps2m_err ps2m_get_device_id(uint8_t __far *device_id); +#pragma aux ps2m_get_device_id = \ + "stc" \ + "mov ax, 0xC204" /* Pointing device: get device ID */ \ + "int 0x15" \ + "mov es:[di], bh" /* Save returned value */ \ + "jnc end" \ + "fail: test ah, ah" \ + "jnz end" \ + "dec ah" \ + "end:" \ + __parm [es di] \ + __value [ah] \ + __modify [ax] + +static ps2m_err ps2m_set_resolution(uint8_t resolution); +#pragma aux ps2m_set_resolution = \ + "stc" \ + "mov ax, 0xC203" /* Pointing device: set resolution (in bh) */ \ + "int 0x15" \ + "jnc end" \ + "fail: test ah, ah" \ + "jnz end" \ + "dec ah" \ + "end:" \ + __parm [bh] \ + __value [ah] \ + __modify [ax] + +static ps2m_err ps2m_set_sample_rate(uint8_t sample_rate); +#pragma aux ps2m_set_sample_rate = \ + "stc" \ + "mov ax, 0xC202" /* Pointing device: set sample rate (in bh) */ \ + "int 0x15" \ + "jnc end" \ + "fail: test ah, ah" \ + "jnz end" \ + "dec ah" \ + "end:" \ + __parm [bh] \ + __value [ah] \ + __modify [ax] + +static ps2m_err ps2m_set_scaling_factor(uint8_t scaling_factor); +#pragma aux ps2m_set_scaling_factor = \ + "stc" \ + "mov ax, 0xC206" /* Pointing device: extended commands (with bh > 0, set scaling factor) */ \ + "int 0x15" \ + "jnc end" \ + "fail: test ah, ah" \ + "jnz end" \ + "dec ah" \ + "end:" \ + __parm [bh] \ + __value [ah] \ + __modify [ax] + +static ps2m_err ps2m_set_callback(LPFN_PS2CALLBACK callback); +#pragma aux ps2m_set_callback = \ + "stc" \ + "mov ax, 0xC207" /* Pointing device: set interrupt callback (in es:bx) */ \ + "int 0x15" \ + "jnc end" \ + "fail: test ah, ah" \ + "jnz end" \ + "dec ah" \ + "end:" \ + __parm [es bx] \ + __value [ah] \ + __modify [ax] + +static ps2m_err ps2m_enable(bool enable); +#pragma aux ps2m_enable = \ + "test bh, bh" /* Ensure enable is either 1 or 0 */ \ + "setnz bh" \ + "stc" \ + "mov ax, 0xC200" /* Pointing device enable/disable (in bh) */ \ + "int 0x15" \ + "jnc end" \ + "fail: test ah, ah" \ + "jnz end" \ + "dec ah" \ + "end:" \ + __parm [bh] \ + __value [ah] \ + __modify [ax] + +static void ps2m_send_imps2_sequence(void) +{ + ps2m_set_sample_rate(PS2M_SAMPLE_RATE_200); + ps2m_set_sample_rate(PS2M_SAMPLE_RATE_100); + ps2m_set_sample_rate(PS2M_SAMPLE_RATE_80); +} + +static bool ps2m_detect_wheel(void) +{ + int err; + uint8_t device_id; + + // Switch to the 4-byte packet and reset the mouse. + // We are not supposed to receive messages at this time anyway. + err = ps2m_init(PS2M_PACKET_SIZE_EXT); + if (err) { + return false; + } + + // Get the initial mouse device id + err = ps2m_get_device_id(&device_id); + if (err || device_id != 0) { + // TODO : Likely have to accept more device_ids here. + return false; + } + + // Send the knock sequence to activate the extended packet + ps2m_send_imps2_sequence(); + + // Now check if the device id has changed + err = ps2m_get_device_id(&device_id); + + return err == 0 && device_id == PS2M_DEVICE_ID_IMPS2; +} + +#endif /* INT15PS2_H */ |