Git SHA gen and common info block

hdl/ip/vhd/espi/sys_regs/espi_regs.rdl

@@ -1,5 +1,5 @@
 // Copyright 2024 Oxide Computer Company
-// This is SystemRDL description of the sw-accesible registers in the Gimlet
+// This is SystemRDL description of the sw-accessible registers in the Gimlet
 // Sequencer FPGA.
 
 addrmap espi_regs {

hdl/ip/vhd/info/BUCK

@@ -0,0 +1,52 @@
+load("//tools:hdl.bzl", "vhdl_unit", "vunit_sim")
+load("//tools:rdl.bzl", "rdl_file")
+
+rdl_file(
+    name = "info_regs_pkg",
+    src = "info_regs.rdl",
+    outputs = ["info_regs_pkg.vhd", "info_regs.html"],
+    visibility = ['PUBLIC']
+)
+
+# Janky generate git sha via genrule
+# There are a lot of better ways this might be done, but this was the simplest.
+# It does mean there's a re-build for any change to the git repo, but for now that's fine.
+# Longer-term, we might evaluate backannotating ROMs or something with this build info
+genrule(
+    name = "git_sha",
+    out = "git_sha_pkg.vhd",
+    default_outs = ["git_sha_pkg.vhd"],
+    cmd = '''echo "library ieee;\nuse ieee.std_logic_1164.all;\npackage git_sha_pkg is\n    constant short_sha : std_logic_vector(31 downto 0) := X\\""`git rev-parse --short=8 HEAD`\\"";\nend package git_sha_pkg;\" > $OUT''',
+
+)
+
+vhdl_unit(
+    name = "git_sha_pkg",
+    srcs = [":git_sha"],
+    visibility = ['PUBLIC']
+)
+
+#  2008-based signals in the this block
+vhdl_unit(
+    name = "info_2k8",
+    srcs = ["info_2k8.vhd"],
+    deps = [
+        ":git_sha_pkg",
+        ":info_regs_pkg",
+        ],
+    standard = "2008",
+    visibility = ['PUBLIC']
+)
+
+# Wrapping previous block in a 2019-compatible block using
+# axi interfaces
+vhdl_unit(
+    name = "info",
+    srcs = ["info.vhd"],
+    deps = [
+        ":info_2k8",
+        "//hdl/ip/vhd/axi_blocks:axilite_common_pkgs",
+        ],
+    standard = "2019",
+    visibility = ['PUBLIC']
+)

hdl/ip/vhd/info/info.vhd

@@ -0,0 +1,61 @@
+-- This Source Code Form is subject to the terms of the Mozilla Public
+-- License, v. 2.0. If a copy of the MPL was not distributed with this
+-- file, You can obtain one at https://mozilla.org/MPL/2.0/.
+--
+-- Copyright 2024 Oxide Computer Company
+
+-- 2019-compatible wrapper for basic board information registers
+
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+use ieee.numeric_std_unsigned.all;
+use work.axil8x32_pkg.all;
+
+entity info is
+    generic(
+        hubris_compat_num_bits: positive range 1 to 31;
+    );
+    port (
+        clk   : in    std_logic;
+        reset : in    std_logic;
+        -- System Interface
+        hubris_compat_pins: in std_logic_vector(hubris_compat_num_bits-1 downto 0);
+        -- axi interface. This is not using VHDL2019 views so that it's compatible with
+        -- GHDL/yosys based toolchains
+        axi_if : view axil_target;
+
+
+    );
+end entity;
+
+architecture rtl of info is
+
+begin
+    info_inst: entity work.info_2k8
+     generic map(
+        hubris_compat_num_bits => hubris_compat_num_bits
+    )
+     port map(
+        clk => clk,
+        reset => reset,
+        hubris_compat_pins => hubris_compat_pins,
+        awvalid => axi_if.write_address.valid,
+        awready => axi_if.write_address.ready,
+        awaddr => axi_if.write_address.addr,
+        wvalid => axi_if.write_data.valid,
+        wready => axi_if.write_data.ready,
+        wdata => axi_if.write_data.data,
+        wstrb => axi_if.write_data.strb,
+        bvalid => axi_if.write_response.valid,
+        bready => axi_if.write_response.ready,
+        bresp => axi_if.write_response.resp,
+        arvalid => axi_if.read_address.valid,
+        arready => axi_if.read_address.ready,
+        araddr => axi_if.read_address.addr,
+        rvalid => axi_if.read_data.valid,
+        rready => axi_if.read_data.ready,
+        rdata => axi_if.read_data.data,
+        rresp => axi_if.read_data.resp
+    );
+end rtl;

hdl/ip/vhd/info/info_2k8.vhd

@@ -0,0 +1,145 @@
+-- This Source Code Form is subject to the terms of the Mozilla Public
+-- License, v. 2.0. If a copy of the MPL was not distributed with this
+-- file, You can obtain one at https://mozilla.org/MPL/2.0/.
+--
+-- Copyright 2024 Oxide Computer Company
+
+-- Common register block for basic board information
+
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+use ieee.numeric_std_unsigned.all;
+
+use work.info_regs_pkg.all;
+use work.git_sha_pkg.all;
+
+entity info_2k8 is
+    generic(
+        hubris_compat_num_bits: positive range 1 to 31
+    );
+    port (
+        clk   : in    std_logic;
+        reset : in    std_logic;
+        -- System Interface
+        hubris_compat_pins: in std_logic_vector(hubris_compat_num_bits-1 downto 0);
+        -- axi interface. This is not using VHDL2019 views so that it's compatible with
+        -- GHDL/yosys based toolchains
+        -- write address channel
+        awvalid : in std_logic;
+        awready : out std_logic;
+        awaddr : in std_logic_vector(7 downto 0) ;
+        -- write data channel
+        wvalid : in std_logic;
+        wready : out std_logic;
+        wdata : in std_logic_vector(31 downto 0);
+        wstrb : in std_logic_vector(3 downto 0); -- un-used
+        -- write response channel
+        bvalid : out std_logic;
+        bready : in std_logic;
+        bresp : out std_logic_vector(1 downto 0);
+        -- read address channel
+        arvalid : in std_logic;
+        arready : out std_logic;
+        araddr : in std_logic_vector(7 downto 0);
+        -- read data channel
+        rvalid : out std_logic;
+        rready : in std_logic;
+        rdata : out std_logic_vector(31 downto 0);
+        rresp : out std_logic_vector(1 downto 0)
+
+
+    );
+end entity;
+
+architecture rtl of info_2k8 is
+    constant OKAY               : std_logic_vector(1 downto 0) := "00";
+    signal   axi_int_read_ready : std_logic;
+
+    constant identity : identity_type := rec_reset;
+    constant version : version_type := rec_reset;
+    constant git_info : git_info_type := (sha => short_sha);
+    signal checksum : fpga_checksum_type := rec_reset;
+    signal scratchpad : scratchpad_type := rec_reset;
+    signal hubris_compat: hubris_compat_type := rec_reset;
+
+begin
+    bresp  <= OKAY;
+    rresp      <= OKAY;
+
+    wready  <= awready;
+    arready <= not rvalid;
+
+    axi_int_read_ready <= arvalid and arready;
+
+    -- axi transaction mgmt
+    axi_txn: process(clk, reset)
+    begin
+        if reset then
+            awready <= '0';
+            bvalid <= '0';
+            rvalid <= '0';
+        elsif rising_edge(clk) then
+            -- bvalid set on every write,
+            -- cleared after bvalid && bready
+            if awready then
+                bvalid <= '1';
+            elsif bready then
+                bvalid <= '0';
+            end if;
+
+            if axi_int_read_ready then
+                rvalid <= '1';
+            elsif rready then
+                rvalid <= '0';
+            end if;
+
+            -- can accept a new write if we're not
+            -- responding to write already or
+            -- the write is not in progress
+            awready <= not awready and
+                       (awvalid and wvalid) and
+                       (not bvalid or bready);
+        end if;
+    end process;
+
+    write_logic: process(clk, reset)
+    begin
+        if reset then
+            hubris_compat <= rec_reset;
+            scratchpad <= rec_reset;
+        elsif rising_edge(clk) then
+            -- go ahead and flo this every cycle, it's external but not
+            -- changing
+            hubris_compat <= unpack(resize(hubris_compat_pins, 32));
+            if wready then
+                case to_integer(awaddr) is
+                    when FPGA_CHECKSUM_OFFSET => checksum <= unpack(wdata);
+                    when SCRATCHPAD_OFFSET => scratchpad <= unpack(wdata);
+                    when others => null;
+                end case;
+            end if;
+        end if;
+    end process;
+
+    read_logic: process(clk, reset)
+    begin
+        if reset then
+            rdata <= (others => '0');
+        elsif rising_edge(clk) then
+            if (not arvalid) or arready then
+                case to_integer(araddr) is
+                    when IDENTITY_OFFSET => rdata <= pack(identity);
+                    when HUBRIS_COMPAT_OFFSET => rdata <= pack(hubris_compat);
+                    when VERSION_OFFSET => rdata <= pack(version);
+                    when GIT_INFO_OFFSET => rdata <= pack(git_info);
+                    when FPGA_CHECKSUM_OFFSET => rdata <= pack(checksum);
+                    when SCRATCHPAD_OFFSET => rdata <= pack(scratchpad);
+                    when others =>
+                        rdata <= (others => '0');
+                end case;
+            end if;
+        end if;
+    end process;
+
+end rtl;

hdl/ip/vhd/info/info_regs.rdl

@@ -0,0 +1,70 @@
+// Copyright 2024 Oxide Computer Company
+// This is SystemRDL description of the sw-accessible common board-info registers
+
+addrmap info_regs {
+    name = "Board and Build info";
+    desc = "Registers accessible on the Axi bus providing board and build info";
+
+    default regwidth = 32;
+    default sw = rw;
+    default hw = r;
+
+    reg {
+        name = "Identity";
+        desc = "";
+
+        field {
+            default sw = r;
+            desc = "Read-only bits showing 0x1de";
+        } data[32] =  0x1de;
+    } identity;
+
+    reg {
+        name = "Hubris Compatibility Straps";
+        desc = "";
+
+        field {
+            default sw = r;
+            desc = "Read-only bits showing resistor strapping for hubris compatibility value";
+        } data[32] =  0;
+    } hubris_compat;
+
+    reg {
+        name = "Version";
+        desc = "";
+
+        field {
+            default sw = r;
+            desc = "Read-only bits showing 0x1de";
+        } data[32] =  0x1de;
+    } version;
+
+    reg {
+        name = "GIT SHORT SHA";
+        desc = "";
+
+        field {
+             default sw = r;
+            desc = "Read-only bits showing the 4byte short-sha of the git commit";
+        } sha[32] =  0;
+    } git_info;
+
+     reg {
+        name = "FPGA Checksum";
+        desc = "";
+
+        field {
+            desc = "Scribble register, nominally intended to hold the FPGA checksum,
+            used for knowing if the FPGA needs to be re-programmed or not";
+        } data[32] =  0;
+    } fpga_checksum;
+
+    reg {
+        name = "Scratchpad";
+        desc = "";
+
+        field {
+            desc = "Scribble register scratchpad suitable for any software purpose";
+        } data[32] =  0;
+    } scratchpad;
+};

hdl/projects/grapefruit/BUCK

@@ -71,6 +71,7 @@ vhdl_unit(
         ":gfruit_top_regs",
         ":gfruit_sgpio",
         ":reset_sync",
+        "//hdl/ip/vhd/info:info",
         "//hdl/ip/vhd/espi:espi_top",
         "//hdl/ip/vhd/uart:axi_fifo_uart",
         "//hdl/ip/vhd/axi_blocks:axilite_common_pkgs",

hdl/projects/grapefruit/grapefruit_top.vhd

@@ -319,12 +319,15 @@ begin
     -- tristate control for the FMC data bus
     fmc_sp_to_fpga_da <= fmc_internal_data_out when fmc_data_out_enable = '1' else (others => 'Z');
 
-    registers_inst: entity work.registers
+    info_regs: entity work.info
+     generic map(
+        hubris_compat_num_bits => 3
+    )
      port map(
         clk => clk_125m,
         reset => reset_125m,
-        axi_if => responders(0),
-        spi_nor_passthru => open
+        hubris_compat_pins => (others => '0'),
+        axi_if => responders(0)
     );
 
     spi_nor_top_inst: entity work.spi_nor_top

toolchains/BUCK

@@ -1,12 +1,18 @@
 load("@prelude//toolchains:python.bzl", "system_python_bootstrap_toolchain", "system_python_toolchain")
 load("@prelude//toolchains:cxx.bzl", "system_cxx_toolchain")
 load("@prelude//toolchains:remote_test_execution.bzl", "remote_test_execution_toolchain")
+load("@prelude//toolchains:genrule.bzl", "system_genrule_toolchain")
 
 load("vivado_toolchain.bzl", "vivado_toolchain")
 load("vsg_toolchain.bzl", "vsg_toolchain")
 
 load("yosys_toolchain.bzl", "icepack_toolchain", "nextpnr_ice40_toolchain")
 
+system_genrule_toolchain(
+    name = "genrule",
+    visibility = ["PUBLIC"],
+)
+
 system_cxx_toolchain(
     name = "cxx",
     visibility = ["PUBLIC"],