ladybird/Kernel/Console.cpp
Andreas Kling c6f2890d8e Implement a basic way for read() to block.
FileHandle gets a hasDataAvailableForRead() getter.
If this returns true in sys$read(), the task will block(BlockedRead) + yield.
The fd blocked on is stored in Task::m_fdBlockedOnRead.
The scheduler then looks at the state of that fd during the unblock phase.

This makes "sh" restful. :^)

There's still some problem with the kernel not surviving the colonel task
getting scheduled. I need to figure that out and fix it.
2018-10-25 13:09:56 +02:00

77 lines
1.4 KiB
C++

#include "Console.h"
#include "VGA.h"
#include "IO.h"
// Bytes output to 0xE9 end up on the Bochs console. It's very handy.
#define CONSOLE_OUT_TO_E9
static Console* s_the;
Console& Console::the()
{
return *s_the;
}
Console::Console()
{
s_the = this;
}
Console::~Console()
{
}
bool Console::hasDataAvailableForRead() const
{
return false;
}
ssize_t Console::read(byte* buffer, size_t bufferSize)
{
// FIXME: Implement reading from the console.
// Maybe we could use a ring buffer for this device?
// A generalized ring buffer would probably be useful.
return 0;
}
void Console::putChar(char ch)
{
#ifdef CONSOLE_OUT_TO_E9
IO::out8(0xe9, ch);
#endif
switch (ch) {
case '\n':
m_cursorColumn = 0;
if (m_cursorRow == (m_rows - 1)) {
vga_scroll_up();
} else {
++m_cursorRow;
}
vga_set_cursor(m_cursorRow, m_cursorColumn);
return;
}
vga_putch_at(m_cursorRow, m_cursorColumn, ch);
++m_cursorColumn;
if (m_cursorColumn >= m_columns) {
if (m_cursorRow == (m_rows - 1)) {
vga_scroll_up();
} else {
++m_cursorRow;
}
m_cursorColumn = 0;
}
vga_set_cursor(m_cursorRow, m_cursorColumn);
}
ssize_t Console::write(const byte* data, size_t size)
{
if (!size)
return 0;
for (size_t i = 0; i < size; ++i)
putChar(data[i]);
return 0;
}