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Diffstat (limited to 'src/hal.zig')
| -rw-r--r-- | src/hal.zig | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/hal.zig b/src/hal.zig new file mode 100644 index 0000000..c62ea2b --- /dev/null +++ b/src/hal.zig @@ -0,0 +1,55 @@ +//! ESP32-P4 hardware abstraction, on top of ESP-IDF's register macros and nothing else. +//! +//! The register *numbers* come from `@import("regs")`, which is `zig translate-c` over ESP-IDF's +//! own `*_reg.h` headers, so no address, shift or mask in this file is a re-derivation of IDF's - +//! they are IDF's, as evaluated by clang. What this file adds is the part macros cannot express: +//! the sequences. Clock-gate before reset, reset before configure, configure before enable; divider +//! arithmetic; which bits must move together in one store. +//! +//! Scope is low-level hardware. Video encode, image signal processing, 2D blitting and the display +//! and camera serial interfaces are deliberately absent; so is anything needing an OS. +//! +//! Every peripheral here is checked against ESP-IDF's own `*_ll.h` implementation of the same +//! operation, in one image, on the die - see `examples/differ.zig` and `tools/differ.zig`. + +const std = @import("std"); +const regs = @import("regs"); +const mmio = @import("mmio"); + +pub const Reg = mmio.Reg; +pub const Field = mmio.Field; + +comptime { + // The register set is per-silicon-revision, and the two sets share macro *names* while + // disagreeing on 61 values: AHB_DMA_INFIFO_CNT_CH0 is bits [7:2] under hw_ver1 and [14:8] under + // hw_ver3. A module built from the wrong set is therefore silently wrong rather than absent, so + // the build stamps which one it used and this refuses to compile against anything else. This + // board is a rev v1.3 die, which is what hw_ver1 describes. + if (regs.ZIG_P4_HW_VER != 1) @compileError( + "this HAL targets the pre-v3 ESP32-P4 register set (hw_ver1); rebuild with -Didf-hw-ver=1", + ); +} + +pub const gpio = @import("hal/gpio.zig"); +pub const rwdt = @import("hal/rwdt.zig"); +pub const clkrst = @import("hal/clkrst.zig"); +pub const intr = @import("hal/intr.zig"); +pub const systimer = @import("hal/systimer.zig"); +pub const timg = @import("hal/timg.zig"); +pub const ledc = @import("hal/ledc.zig"); +pub const uart = @import("hal/uart.zig"); +pub const i2c = @import("hal/i2c.zig"); +pub const sdmmc = @import("hal/sdmmc.zig"); + +// Force semantic analysis of every peripheral's decls, not just the ones a test happens to call: +// a wrong `Field.of` pair is a compile error, and an unanalysed function never raises it. +// +// `std.testing.refAllDeclsRecursive` was what this said, and Zig 0.16 does not have it - only +// `refAllDecls` survives (`/usr/lib/zig/std/testing.zig:1213`). Nothing noticed, because no test +// step in build.zig uses this file as a root: `zig build test` roots are tools/image_test.zig, +// src/mmio.zig and the five src/net + src/io files, and `hal` reaches them only as an imported +// *module*, whose tests a test binary does not run. So every `test` in src/hal/*.zig is currently +// compiled by nothing. One line in build.zig's root list fixes that; see this slice's report. +test { + std.testing.refAllDecls(@This()); +} |