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| author | user <user@clank> | 2026-07-15 23:44:28 +0200 |
|---|---|---|
| committer | user <user@clank> | 2026-07-15 23:44:28 +0200 |
| commit | de725da74db5cba0f9bfd0755269e1683423d87b (patch) | |
| tree | dc39eca9fbd290393ed51de31eee5e4bd6af8375 /src/tty.asm | |
| download | gbos-de725da74db5cba0f9bfd0755269e1683423d87b.tar.gz gbos-de725da74db5cba0f9bfd0755269e1683423d87b.tar.xz gbos-de725da74db5cba0f9bfd0755269e1683423d87b.zip | |
gbos scaffold: working cooperative microkernel (verified ABAB in emulator)
- fix ClearKernelRAM clobbering the kernel stack (only clear $C000-$CBFF)
- fix SyscallTrap clobbering DE (buffer arg) during table dispatch
- README: run via ~/dev/gbc --headless; note bring-up bugs
Diffstat (limited to 'src/tty.asm')
| -rw-r--r-- | src/tty.asm | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/tty.asm b/src/tty.asm new file mode 100644 index 0000000..d2c1234 --- /dev/null +++ b/src/tty.asm @@ -0,0 +1,15 @@ +; ============================================================================= +; tty.asm - console output over the serial port (emulator debug channel). +; A real gbos would render to VRAM; serial is a zero-VRAM stub that shows up +; in emulator serial logs (bgb/SameBoy) and on link hardware. +; ============================================================================= +INCLUDE "include/gbos.inc" + +SECTION "tty", ROM0 + +; PutChar - A = character. Push to serial data and kick a transfer. +PutChar:: + ld [rSB], a + ld a, $81 ; start transfer, internal clock + ld [rSC], a + ret |