mirror of
https://github.com/subhobhai943/SUB-OS.git
synced 2026-10-25 16:52:29 +00:00
subhobhai943andClaude Opus 5
2d01fd629e
Pressing Esc left the desktop and started the shell, but nothing appeared in the
emulator window -- the session was only visible on the host terminal. Once the
VBE adapter is switched into graphics mode the VGA text buffer at 0xB8000 stops
being scanned out, so every printk after that point reached serial and the
dmesg ring but never the display.
Disabling the DISPI interface does not bring the text console back; QEMU keeps
presenting the last framebuffer surface. So rather than clawing the adapter back
to text mode, the console is now rendered into the framebuffer:
drivers/video/fbcon.c draws the console with the shared 8x8 font and carries a
VT100 subset -- SGR colours, cursor addressing, relative moves, erase-display,
erase-line and save/restore. It presents a fixed 80x25 grid, because that is
the geometry the userland assumes (nano pads its bars with %-80s, the shell
wraps at TTY_WIDTH), with the glyph cell scaled to fill the active resolution.
The TTY driver became the console dispatcher: tty_write, tty_clear and
tty_set_cursor route to fbcon while it owns the display. That last one is what
makes nano work -- it positions with tty_set_cursor() rather than escapes, so
its full-screen repaint was landing as an append-only stream.
Also in this change:
- `video=WIDTHxHEIGHT` on the kernel command line selects the display mode,
defaulting to 1280x720 so a 16:9 host panel is filled rather than pillarboxed
when QEMU goes fullscreen. Rejects modes the heap cannot back.
- `make run-fullscreen`, plus zoom-to-fit on the windowed target, so scaling
preserves the guest aspect ratio instead of stretching it.
- QEMU targets raise vgamem_mb, since a 1280x720 32-bit surface exceeds the
default VGA memory.
- bochs_vbe_disable()/fb_set_active() let the framebuffer be marked dormant so
drawing routines no-op after a mode teardown.
Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01L5yKJT4Wo2cV3rfPrwY5MP
48 lines
1.4 KiB
C
48 lines
1.4 KiB
C
#ifndef _DRIVERS_BOCHS_H
|
|
#define _DRIVERS_BOCHS_H
|
|
|
|
#include <stdint.h>
|
|
#include <stddef.h>
|
|
#include <stdbool.h>
|
|
|
|
#define VBE_DISPI_IOPORT_INDEX 0x01CE
|
|
#define VBE_DISPI_IOPORT_DATA 0x01CF
|
|
|
|
#define VBE_DISPI_INDEX_ID 0x0
|
|
#define VBE_DISPI_INDEX_XRES 0x1
|
|
#define VBE_DISPI_INDEX_YRES 0x2
|
|
#define VBE_DISPI_INDEX_BPP 0x3
|
|
#define VBE_DISPI_INDEX_ENABLE 0x4
|
|
#define VBE_DISPI_INDEX_BANK 0x5
|
|
#define VBE_DISPI_INDEX_VIRT_WIDTH 0x6
|
|
#define VBE_DISPI_INDEX_VIRT_HEIGHT 0x7
|
|
#define VBE_DISPI_INDEX_X_OFFSET 0x8
|
|
#define VBE_DISPI_INDEX_Y_OFFSET 0x9
|
|
|
|
#define VBE_DISPI_DISABLED 0x00
|
|
#define VBE_DISPI_ENABLED 0x01
|
|
#define VBE_DISPI_LFB_ENABLED 0x40
|
|
#define VBE_DISPI_NOCLEARMEM 0x80
|
|
|
|
typedef struct {
|
|
uint32_t current_width;
|
|
uint32_t current_height;
|
|
uint32_t current_bpp;
|
|
uint64_t lfb_phys_addr;
|
|
uint16_t vbe_version;
|
|
bool available;
|
|
} bochs_vbe_info_t;
|
|
|
|
bool bochs_vbe_init(void);
|
|
bool bochs_vbe_is_available(void);
|
|
int bochs_vbe_set_mode(uint32_t width, uint32_t height, uint32_t bpp);
|
|
|
|
// Leave graphics and hand the adapter back to VGA text mode. Disabling the
|
|
// DISPI interface restores the mode the BIOS left behind, which is what makes
|
|
// the 80x25 console visible again after a desktop session ends.
|
|
void bochs_vbe_disable(void);
|
|
bool bochs_vbe_is_enabled(void);
|
|
const bochs_vbe_info_t* bochs_vbe_get_info(void);
|
|
|
|
#endif // _DRIVERS_BOCHS_H
|