mirror of
https://github.com/RGBCube/serenity
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6d2c298b66
As there is no need for a Prekernel on aarch64, the Prekernel code was moved into Kernel itself. The functionality remains the same. SERENITY_KERNEL_AND_INITRD in run.sh specifies a kernel and an inital ramdisk to be used by the emulator. This is needed because aarch64 does not need a Prekernel and the other ones do.
69 lines
1.4 KiB
C++
69 lines
1.4 KiB
C++
/*
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* Copyright (c) 2021, Nico Weber <thakis@chromium.org>
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* Copyright (c) 2021, Jesse Buhagiar <jooster669@gmail.com>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/Types.h>
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namespace Prekernel {
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struct UARTRegisters;
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// Abstracts the PL011 UART on a Raspberry Pi.
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// (The BCM2711 on a Raspberry Pi 4 has five PL011 UARTs; this is always the first of those.)
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class UART {
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public:
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static UART& the();
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void send(u32 c);
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u32 receive();
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void print_str(const char* s)
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{
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while (*s)
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send(*s++);
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}
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void print_num(u64 n)
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{
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char buf[21];
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int i = 0;
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do {
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buf[i++] = (n % 10) + '0';
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n /= 10;
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} while (n);
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for (i--; i >= 0; i--)
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send(buf[i]);
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}
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void print_hex(u64 n)
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{
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char buf[17];
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static const char* digits = "0123456789ABCDEF";
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int i = 0;
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do {
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buf[i++] = digits[n % 16];
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n /= 16;
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} while (n);
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send(static_cast<u32>('0'));
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send(static_cast<u32>('x'));
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buf[16] = '\0';
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for (i--; i >= 0; i--) {
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send(buf[i]);
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}
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}
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private:
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UART();
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void set_baud_rate(int baud_rate, int uart_frequency_in_hz);
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void wait_until_we_can_send();
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void wait_until_we_can_receive();
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UARTRegisters volatile* m_registers;
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};
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}
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