rajamesandClaude Opus 5.5
0e2c60dac3
boards/BRINGUP.md R2/R3, FABRIC-3 SXXXIX. The entry stub cleans the cache over the image, builds an identity map (the image's GiB Normal, the rest Device) and enables MMU and caches at EL2 (or EL1); rpi5_mmu.c makes the devicetree's RAM Normal and the framebuffer uncached. Mailbox waits give up after one second; the buffer is cleaned around the exchange; the framebuffer address goes through dma-ranges, not a Pi 4 mask. New rpi5-rehearsal target runs the native image on QEMU virt at EL2. It found three more that would each have stopped the board: the PL011 shift (mine, c9519173; the host test asserted it), the GIC address not carried through /soc's ranges (new fdt_reg_address(), checked against the real Pi 5 DTB), and no timer IRQ at EL2 (HCR_EL2.IMO/FMO/AMO). Rehearsal: POST 1052 passed, same parity hash as UEFI. Standard acceptance on three ISAs: POST 1052, hash 0x82f4ae7cb2e2d424. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
71 lines
3.0 KiB
C
71 lines
3.0 KiB
C
/*
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StarForth — Steady-State Virtual Machine Runtime
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Copyright (c) 2023–2025 Robert A. James. All rights reserved.
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Licensed under the StarForth License, Version 1.0.
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*/
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/**
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* rpi5_mailbox.h - VideoCore mailbox property-interface framebuffer
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* setup, for the native (non-UEFI) Raspberry Pi 5 boot path
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* (FABRIC-3.md §IV.3 item 3).
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*
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* Register layout, message/tag format, and property-tag IDs confirmed
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* against multiple sources before writing `rpi5_mailbox.c` — see that
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* file's own doc comment for exactly which, and what (if anything)
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* remains unverified against real hardware (not in hand until
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* 2026-09-17; this driver has never run on real silicon).
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*/
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#ifndef STARKERNEL_RPI5_MAILBOX_H
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#define STARKERNEL_RPI5_MAILBOX_H
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#include <stdint.h>
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/* Mirrors uefi.h's FramebufferInfo exactly -- populated by
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* rpi5_mailbox_get_framebuffer() the same shape UEFI GOP already
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* populates it, so console.c/vt100.c/framebuffer.c need no changes at
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* all for this path. Not #include-ing uefi.h here (that header is a
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* large UEFI-protocol grab-bag; this driver only needs this one
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* struct's shape) -- callers that already have a `FramebufferInfo*`
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* (from uefi.h) can pass it directly, since the two struct
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* definitions are kept in exact field-for-field sync by convention.
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*/
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typedef struct {
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void* base;
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uint64_t size;
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uint32_t width;
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uint32_t height;
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uint32_t pixels_per_scanline;
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uint32_t pixel_format; /* 0 = RGB, matches uefi.h's
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* PixelRedGreenBlueReserved8BitPerColor --
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* this driver always requests RGB pixel
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* order explicitly (tag 0x00048006), never
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* leaves it at hardware/firmware default. */
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} Rpi5FramebufferInfo;
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/**
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* @brief Request a framebuffer from the VideoCore firmware via the
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* mailbox property interface, at the requested resolution/depth.
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*
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* Sends one buffer with all six setup tags (physical size, virtual
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* size, depth, pixel order, virtual offset, allocate) plus a
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* get-pitch tag, in one request/response round trip.
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*
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* @param dtb Devicetree blob (passed to `rpi5_mailbox_base()`).
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* @param width Requested physical+virtual width, pixels.
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* @param height Requested physical+virtual height, pixels.
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* @param bpp Requested bits per pixel (32 is the only depth this
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* driver has been designed against; others are not
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* refused outright but are unverified).
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* @param out Populated on success; untouched on failure.
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* @return 0 on success, negative on failure: -2 no mailbox node in the
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* DTB, -3 the VC firmware rejected the request, -4 a response
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* came back empty, -5 no answer within one second (every wait is
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* bounded), -6 the devicetree's dma-ranges cannot place the
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* framebuffer's bus address.
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*/
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int rpi5_mailbox_get_framebuffer(const void* dtb, uint32_t width, uint32_t height,
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uint32_t bpp, Rpi5FramebufferInfo* out);
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#endif /* STARKERNEL_RPI5_MAILBOX_H */
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