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Diffstat (limited to 'README.md')
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@@ -38,7 +38,7 @@ QEMU can be adapted to use this boot flow as well (the default is different). Required dependencies: -* zig ^0.12.0 +* zig (most recent release version at the time of the latest commit) * init executable (see below) To make a debug build of this kernel, run: @@ -261,15 +261,15 @@ You can also use `riscv64-elf-gdb /path/to/srvre_kernel.elf` directly. # Translating device trees to the HWI (Hardware Info) format -The HWI format was developed as a more robust and efficient alternative -to standard device trees. The `hwi(1)` tool reads a textual representation -from stdin and writes the corresponding binary representation to stdout. -The values can be obtained from the device tree, but automated conversion -is not implemented due to the complexity of the device tree format. +The HWI format was developed as a more robust and efficient alternative to +standard device trees. The `hwi` tool reads a text representation from stdin +and writes the corresponding binary representation to stdout. The values can +be obtained from the device tree, but automated conversion is not implemented +due to the complexity of the device tree format. ## Build hwi -The `hwi(1)` tool can be built easily: +The `hwi` tool can be built easily: ``` zig build-exe src/hwi.zig @@ -277,10 +277,10 @@ zig build-exe src/hwi.zig This produces a `hwi` binary in the current working directory. -## The hwi tool +## Use hwi tool -You can use the `hwi(1)` command to convert from the textual representation -to the binary representation: +You can use the `hwi` command to convert from the text representation to the +binary representation: ``` hwi < src/cfg/platform/<PLATFORM>.txt > src/cfg/platform/<PLATFORM>.hwi @@ -296,60 +296,9 @@ hwi > src/cfg/platform/<PLATFORM>.hwi Press Control+D after finishing the last line (and pressing Enter) to close stdin, quitting the tool. -## Textual format +## Text and binary formats -The textual HWI format is a list of entries where each entry -is represented by a line of text. Separation is done using a single `\n` -character. - -The entry format is as follows: - -``` -<KIND> <ADDRESS> <SIZE> [VALUE] -``` - -* `<KIND>`: The kind of the entry. Can be `cpus`, `plic`, `pcie` or `pci`. -* `<ADDRESS>`: The base address for memory-mapped I/O. Ignored (and preferably set to zero) if not applicable. -* `<SIZE>`: The size of the memory-mapped I/O region. Ignored (and preferably set to zero) if not applicable. -* `[VALUE]`: Optional additional (numeric) data. Defaults to zero if unspecified. - -Numeric values are represented as unsigned 64-bit integers and may be parsed -from non-decimal notations. -See [the documentation of std.fmt.parseUnsigned](https://ziglang.org/documentation/0.12.0/std/#std.fmt.parseUnsigned) -for details on supported notations. - -### cpus - -Gives information about the processors. MMIO is not applicable. -The `VALUE` parameter holds the timebase frequency (used for interrupt timers). - -### plic - -Gives information about the Platform-Level Interrupt Controller. -MMIO is applicable. The `VALUE` parameter is ignored. - -### pcie - -Gives information about an ECAM PCI(e) controller. MMIO is applicable. -The `VALUE` parameter is ignored. - -### pci - -Gives information about a legacy CAM PCI controller. MMIO is applicable. -The `VALUE` parameter is ignored. - -## Binary format - -The binary HWI format is a sequence of entry structures that isn't aware -of endianness. The number of entries is `n/32` where `n` is the size -of a valid HWI sequence in bytes. - -The entry format is as follows: - -``` -kind: enum(u32) { cpus, plic, pcie, pci } -ALIGNMENT (u32) -reg.addr: u64 -reg.len: u64 -value: u64 -``` +The [text](https://himbeerserver.de/md/srvre/kernel/wiki/hwi.md#text-format) +and +[binary](https://himbeerserver.de/md/srvre/kernel/wiki/hwi.md#binary-format) +formats are documented in the wiki. |