* [metal] Add a uprintf() routine, for non-emergency boot logging
* [metal] _Really_ push forward timing of VGA TTY initialization
* [metal] Do something useful with uprintf()
* [metal] Locate some ACPI tables, for later hardware detection
Specifically the code now tries to find the ACPI RSDP,
RSDT/XSDT, FADT, & MADT tables, whether in legacy BIOS
bootup mode or in a UEFI bootup. These are useful for
figuring out how to (re)enable asynchronous interrupts
in legacy 8259 PIC mode.
* [metal] Refactoring: separate out sys_writev_vga() and _vga_init() modules
* [metal] Read VGA info from BDA before long mode entry, not after
If using a pre-existing VGA text console, the VGA initialization
code now retrieves the cursor position & character height from
the BIOS data area while still in real mode — rather than
reading from the BIOS data area only after entering long mode.
(This should help make the code more correct, if Cosmopolitan
were to support UEFI graphics output in the future. If the
program were booted via UEFI, then the long mode IsMetal()
code would still be activated, but the BIOS data area might
not have been initialized in that case.)
This change also means that there are now a few more fields
in the `struct mman`.
* [metal] VGA console can now show "screen of death" upon a crash
There is now a new function _klog_vga(), which can be called
by kprintf() to output system messages — e.g. information about
CPU exceptions — on the VGA screen.
* [metal] CPU exception handler now dumps cr2 value
* [metal] Add demo of program crash reporting w/ bare metal VGA TTY
* [metal] Reduce size of "screen of death" code
* Test output of colors for VGA graphics modes in examples/vga.c
* [metal] Character output in VGA graphics modes is mostly working
* [metal] Mention magic key to switch video mode, at bootup
If your main module has this declaration:
STATIC_YOINK("vga_console");
Then a VGA driver will be linked into your executable which
displays your stdio characters on the PC display, whereas
before we could only use the serial port. Your display is an
ANSI terminal and it's still a work in progress.
