diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arch/amd64/isa/i8254.S | 90 | ||||
| -rw-r--r-- | sys/inc/arch/amd64/i8254.h | 47 |
2 files changed, 137 insertions, 0 deletions
diff --git a/sys/arch/amd64/isa/i8254.S b/sys/arch/amd64/isa/i8254.S new file mode 100644 index 0000000..7efd3cf --- /dev/null +++ b/sys/arch/amd64/isa/i8254.S @@ -0,0 +1,90 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + + .set I8254_COMMAND, 0x43 + .set I8254_CHANNEL0, 0x40 + + .text + .globl i8254_set_count +i8254_set_count: + /* + * RDI: Count + */ + + push %r12 + push %r13 + push %r14 + push %r15 + push %rbx + push %rbp + + mov %rdi, %rax /* Count -> RAX */ + mov $0x34, %al /* Latch lo/hi bytes */ + out %al, $I8254_COMMAND /* Send the command */ + out %al, $I8254_CHANNEL0 /* Write low byte */ + shr $8, %ah /* Shift down, get high byte */ + out %al, $I8254_CHANNEL0 /* Write high byte */ + + pop %rbp + pop %rbx + pop %r15 + pop %r14 + pop %r13 + pop %r12 + retq + + .globl i8254_get_count +i8254_get_count: + push %r12 + push %r13 + push %r14 + push %r15 + push %rbx + push %rbp + + mov $0x00, %al /* Get the current counter */ + out %al, $I8254_COMMAND /* Send the command */ + xor %rdx, %rdx /* Make sure RDX is zeroed */ + in $I8254_CHANNEL0, %al /* Read low byte */ + mov %al, %dl /* Set low byte */ + in $I8254_CHANNEL0, %al /* Read high byte */ + shl $8, %dh /* Shift to make room */ + or %al, %dl /* Merge high and low */ + mov %rdx, %rax /* Return what we got */ + + pop %rbp + pop %rbx + pop %r15 + pop %r14 + pop %r13 + pop %r12 + retq + +/* vim: ft=gas : +*/ diff --git a/sys/inc/arch/amd64/i8254.h b/sys/inc/arch/amd64/i8254.h new file mode 100644 index 0000000..c747d66 --- /dev/null +++ b/sys/inc/arch/amd64/i8254.h @@ -0,0 +1,47 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _MACHINE_I8254_H_ +#define _MACHINE_I8254_H_ + +#include <sys/types.h> + +/* + * Set the current counter value of the i8254 + * main channel + */ +void i8254_set_count(uint16_t count); + +/* + * Get the current count from the i8254 main + * channel + */ +uint16_t i8254_get_count(void); + +#endif /* !_MACHINE_I8254_H_ */ |