initial import

1 files changed, 124 insertions, 0 deletions

diff --git a/ps2.h b/ps2.h
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+++ b/ps2.h
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+/*
+ * 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 PS2_H
+#define PS2_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+enum {
+	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,
+};
+
+#pragma aux PS2_CB far loadds parm reverse caller []
+// TODO: ax and es look not be preserved with this. VBox BIOS already preserves them though.
+
+/** Invoked by the BIOS when there is a mouse event.
+ *  @param status combination of PS2M_STATUS_* flags */
+typedef void (__far * LPFN_PS2CALLBACK)(uint8_t status, uint8_t x, uint8_t y, uint8_t z);
+
+static inline void cli(void);
+#pragma aux cli = "cli"
+
+static inline void sti(void);
+#pragma aux sti = "sti"
+
+static uint8_t ps2_init(void);
+#pragma aux ps2_init = \
+	"stc"              /* If nothing happens, assume failure */ \
+	"mov ax, 0xC205"   /* Pointing device: initialization */ \
+	"mov bh, 3"        /* Use 3 byte packets */ \
+	"int 0x15" \
+	"jc fail" \
+	\
+	"mov ax, 0xC201"   /* Pointing device: reset */ \
+	"int 0x15" \
+	"jc fail" \
+	\
+	"mov ax, 0xC203"   /* Pointing device: set resolution */ \
+	"mov bh, 3"        /* 3 count per mm = ~ 200 ppi */ \
+	"int 0x15" \
+	"jc fail" \
+	\
+	"mov ax, 0xC202"   /* Pointing device: set sample rate*/ \
+	"mov bh, 5"        /* 2: 40 samples per second */ \
+	"int 0x15" \
+	"jc fail" \
+	\
+	"mov ax, 0xC206"   /* Pointing device: extended commands */ \
+	"mov bh, 1"        /* Set 1:1 scaling */ \
+	"int 0x15" \
+	"jc fail" \
+	\
+	"mov ah, 0"        /* Success */ \
+	"jmp end" \
+	\
+	"fail: test ah, ah" /* Ensure we have some error code back, set ah to ff if we don't */ \
+	"jnz end" \
+	"mov ah, 0xFF" \
+	"end:" \
+	__value [ah] \
+	__modify [ax]
+
+static uint8_t ps2_set_callback(LPFN_PS2CALLBACK callback);
+#pragma aux ps2_set_callback = \
+	"stc"              /* If nothing happens, assume failure */ \
+	"mov ax, 0xC207"   /* Pointing device: set interrupt callback (in es:bx) */ \
+	"int 0x15" \
+	"jc fail" \
+	\
+	"mov ah, 0"        /* Success */ \
+	"jmp end" \
+	\
+	"fail: test ah, ah" /* Ensure we have some error code back */ \
+	"jnz end" \
+	"mov ah, 0xFF" \
+	"end:" \
+	__parm [es bx] \
+	__value [ah] \
+	__modify [ax]
+
+static uint8_t ps2_enable(bool enable);
+#pragma aux ps2_enable = \
+	"test bh, bh"      /* Ensure enable is either 1 or 0 */ \
+	"setnz bh" \
+	"stc"              /* If nothing happens, assume failure */ \
+	"mov ax, 0xC200"   /* Pointing device enable/disable (in bh) */ \
+	"int 0x15" \
+	"jc fail" \
+	\
+	"mov ah, 0"        /* Success */ \
+	"jmp end" \
+	\
+	"fail: test ah, ah" /* Ensure we have some error code back */ \
+	"jnz end" \
+	"mov ah, 0xFF" \
+	"end:" \
+	__parm [bh] \
+	__value [ah] \
+	__modify [ax]
+
+#endif