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Kernel: Abstract platform-specific serial port access from kprintf

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kprintf should not really care about the hardware-specific details of
each UART or serial port out there, so instead of using x86 specific
instructions, let's ensure that we will compile only the relevant code
for debug output for a targeted-specific platform.
This commit is contained in:
Liav A 2022-09-02 13:15:27 +03:00 • committed by Linus Groh
parent d5ee03ef5b
commit a02c9c9569
6 changed files with 109 additions and 28 deletions
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48
Kernel/Arch/x86/common/DebugOutput.cpp Normal file
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@ -0,0 +1,48 @@
/*
* Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Arch/DebugOutput.h>
#include <Kernel/Arch/x86/IO.h>
#include <Kernel/Arch/x86/common/BochsDebugOutput.h>
namespace Kernel {
static constexpr u16 serial_com1_io_port = 0x3F8;
void bochs_debug_output(char ch)
{
IO::out8(IO::BOCHS_DEBUG_PORT, ch);
}
void debug_output(char ch)
{
static bool serial_ready = false;
static bool was_cr = false;
if (!serial_ready) {
IO::out8(serial_com1_io_port + 1, 0x00);
IO::out8(serial_com1_io_port + 3, 0x80);
IO::out8(serial_com1_io_port + 0, 0x02);
IO::out8(serial_com1_io_port + 1, 0x00);
IO::out8(serial_com1_io_port + 3, 0x03);
IO::out8(serial_com1_io_port + 2, 0xC7);
IO::out8(serial_com1_io_port + 4, 0x0B);
serial_ready = true;
}
while ((IO::in8(serial_com1_io_port + 5) & 0x20) == 0)
;
if (ch == '\n' && !was_cr)
IO::out8(serial_com1_io_port, '\r');
IO::out8(serial_com1_io_port, ch);
was_cr = ch == '\r';
}
}