| Filename | Latest commit message | Latest commit date |
|---|---|---|
c84d06c5b1
Gate 0's last item, "delete the cell grid" -- done as far as it should be, and the rest of it retired, which is the part worth explaining. include/text.h made the case against the grid in four charges: it cannot do variable-width glyphs, cannot position text off a multiple of eight, cannot anti-alias, and cannot hold a codepoint above 255. Every one of those was about the *drawing layer*, and every one is now false -- glyphs carry metrics, PSOGM positions text at arbitrary pixels, the TrueType path blends 8-bit coverage, and vtcell.ch is a uint32. What is left is a grid in vt.c, and deleting that would not modernise the console; it would stop it being a terminal. VT100 escapes address columns, TIOCGWINSZ reports rows and columns, and every program that draws a box assumes both. So the item is checked with its remainder rewritten to say what was actually wrong, rather than ticked as if the original wording had been carried out. **What was actually wrong was the duplicate.** gfx.c walked font_data and blitted glyphs its own way; text.c did the same job into a struct surface, for no caller but a sysrq self-test. Two implementations of bearings, coverage and clipping, which had to agree about a cell size only one of them was told had changed -- and they did not agree, which is why every line of PSOGM once drew the next character's bitmap underneath itself. There is one now, and the mechanism is the pleasing part: the console hands text_draw_glyph() **the cell as a surface of its own** -- same pixels, same stride, origin moved and bounds set to that cell. Clipping a tall ascender to its line is then the same bounds check that clips to the edge of a screen, and there is no second notion of clipping in the tree. `surface_sub()` is six lines and replaced fourteen of hand-written comparisons. The bitmap is reached through font_builtin() like any other provider, so the early console and the real one are one path with different metrics, and the `if (!cfont)` branch that walked the array is gone. gfx.c no longer includes font.h; text.c does, being the only file left that reads it -- which also retires the note in text.c explaining why it could not. struct surface gained a bpp, because gfx_draw_pixel handles 16, 24 and 32 and whatever replaces it has to as well. Zero means 32: a UEFI GOP has no other format and the loader publishes 32 unconditionally, so callers that do not care say nothing. One behaviour change, and it is the documented one: a codepoint the font cannot draw is now a substituted glyph rather than a blank cell. text.h argues for that directly -- "a missing glyph that draws nothing makes text silently shorter and the fault impossible to see". Verified by screendump: the console renders correctly, PSOGM renders correctly, and `echo t > /proc/sysrq` still draws its specimen through the surface path with the back buffer at 32bpp. Both supported configurations: one boot each, no traps, no panics, socktest and memfdtest green. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> |
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| .. | ||
| 1.0.md | ||
| foundations.md | ||
| hybrid.md | ||
| README.md | ||
| roadmap.md | ||
| schapi.md | ||
| wayland.md | ||
What happens next
Everything in this directory is unbuilt. When a piece of it is finished it leaves — deleted from here, rewritten as a description in ../architecture/. See the rule.
Read 1.0.md first.
It draws a finish line and puts most of the work below on the far side of it. Anything not named there is not being worked on, and the documents in this directory describe more than 1.0 contains.
It also holds the register of unfinished work, which is the one place anything half-built is listed. No new capability starts until that register is empty, and a row leaves it only by being finished or by being deleted from the tree.
The three current decisions
Taken together, because they turn out to need the same foundation.
| wayland.md | The GUI stack becomes Wayland. SchWM and SchDE are deleted — actually gone from the tree, not marked; Schcom survives and changes its wire format. |
| Built. All four mechanisms exist, the GPU driver runs outside the kernel, it survives being killed, and the display mode can be changed from a process. H4 (USB) was withdrawn rather than left open — USB is the bus peripherals arrive on, not a peripheral. | |
| Built. PID 1 is now a role the kernel refills; the description moved to ../architecture/init.md. |
And the one they all wait on:
| foundations.md | Descriptor passing, shared memory, sockets in the filesystem. The critical path. Item 1 is built — sendmsg/recvmsg with SCM_RIGHTS. |
And the one that says which parts of the above are actually being worked on:
| 1.0.md | The finish line. Four gates, and everything else explicitly deferred. |
And the one the hybrid mechanisms were built for:
Built. The Linux Driver Layer for SchOS: someone else's drivers, in a process, reached through /dev/pci. ping works over 8139too and over e1000. The description moved to ../architecture/ldls.md. |
|
Built, all of it, including the network transport. A debugger that observes rather than halts and answers in this kernel's own vocabulary: symbols, a log that outlives the kernel, /dev/dbg, whose, hardware watchpoints, and schdbgd. The description moved to ../architecture/debugging.md. |
Two longer-horizon documents sit behind these: schapi.md, the API layering and the compatibility promise, and roadmap.md, which holds everything still open that is not one of the three above.
The order
Set by 1.0.md, which is the authority. In short:
0. Fix what is already wrong — first
Not a document of its own; it is Gate 0 of 1.0.md, assembled from the What it does not do sections in ../architecture/.
Before any new capability, and the reason is the one that put
netdev_selftest() before the TCP/IP stack: a compositor built on a kernel with
an unexplained hang and a socket layer that reports success for things it did not
do will fail in ways indistinguishable from its own bugs.
1. foundations.md — the critical path
Both the Wayland work and the hybrid work stop here. Descriptor passing and shared memory are the substrate for handing a buffer to a compositor and for handing a device to a driver process. Doing it once for both is the entire reason these are one plan rather than three.
2. init.md — before the desktop, not after — done
A compositor being brought up for the first time crashes constantly, and something that restarts it and says why is worth far more during that work than at the end of it. Built; see ../architecture/init.md.
3. hybrid.md — moved up, and the reason is worth recording
This document used to put the hybrid work after 1.0, deliberately last, on this argument:
designing a userspace driver interface with no driver consuming it produces an interface that is wrong in ways nobody can see
The argument was sound and the conclusion drawn from it was wrong. What forced the change was the driver situation: SchOS cannot write a driver for every device that exists, no project can, and the only route to the hardware support an established OS has is a compatibility layer with the foreign drivers kept outside the kernel. That layer is this plan's mechanisms. It is not optional and it is not late work.
The original argument still holds, and it is answered rather than ignored:
SchOS's own drivers are the consumers. vgpud is a real driver, with real
requirements, and building the interface against it is what keeps it a general
mechanism rather than a hole shaped like something foreign. The compositor is
still a demanding consumer — it is no longer the only one available.
Four mechanisms, all built. One eviction done, the second withdrawn with its reasons recorded, and the foreign driver host they were for is ../architecture/ldls.md — built, and carrying packets.
4. wayland.md — with the GPU driver either side of the seam
W1–W3 and a terminal. W4 and W5 are post-1.0. Item 1 of foundations.md —
descriptor passing — was the thing it could not start without, and it now
exists.
In one sentence
Fix what is broken, build the descriptor-passing and shared-memory substrate, make init survivable, move the drivers out through an interface SchOS's own drivers have to live with first — and put a terminal on the screen.
What this plan does not address
Stated here so it is not mistaken for covered:
- No IOMMU, so the hybrid work isolates against bugs and not against a hostile driver.
- No page cache, so
foundations.mddelivers amemfdand not a general answer to shared file mappings. The general answer is still owed. - No garbage collector for descriptors in flight, so an
AF_UNIXsocket passed over itself and never received leaks. Bounded at thirty-two sockets, and nothing on this plan does it. - No dynamic linking, so no Mesa, no accelerated clients, and no third party
shipping a
.sofor anything. - A new compatibility surface between PID 1 and PID 2, created by a plan whose own schapi.md §3 spends a section warning about those.
- The three open networking items —
getsockname, routing, and interrupt-driven receive — are untouched by any of this and still open. They are in roadmap.md.