[hal] WIP: Integrate picolibc and UART HAL testing

cmake/picolibc.cmake

@@ -0,0 +1,64 @@
+# Copyright 2024 ETH Zurich and University of Bologna.
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Viviane Potocnik <[email protected]>
+
+include(ExternalProject)
+
+message(STATUS "[CHIMERA-SDK] Setting up picolibc for target ${TARGET}")
+
+foreach(var CROSS_C_COMPILER CROSS_C_COMPILER_ARGS CROSS_AR CROSS_STRIP CROSS_CPU CROSS_CPU_FAMILY CROSS_ENDIAN CROSS_SYSTEM CROSS_C_ARGS CROSS_C_LINK_ARGS)
+    if(NOT DEFINED ${var})
+        message(FATAL_ERROR "[CHIMERA-SDK] Variable ${var} is not set. It must be defined before including picolibc.cmake.")
+    endif()
+endforeach()
+
+# Prepare Meson arrays
+function(prepare_meson_array output_var input_string)
+    string(REPLACE " " ";" temp_list "${input_string}")
+    set(formatted_list "")
+    foreach(item IN LISTS temp_list)
+        list(APPEND formatted_list "'${item}'")
+    endforeach()
+    string(JOIN ", " result ${formatted_list})
+    set(${output_var} "${result}" PARENT_SCOPE)
+endfunction()
+
+prepare_meson_array(CROSS_C_COMPILER_ARGS_LIST "${CROSS_C_COMPILER_ARGS}")
+prepare_meson_array(CROSS_C_ARGS_LIST "${CROSS_C_ARGS}")
+prepare_meson_array(CROSS_C_LINK_ARGS_LIST "${CROSS_C_LINK_ARGS}")
+
+set(PICOLIBC_SRC_DIR ${CMAKE_BINARY_DIR}/picolibc-src)
+set(PICOLIBC_BUILD_DIR ${CMAKE_BINARY_DIR}/picolibc-build-${TARGET})
+set(PICOLIBC_INSTALL_DIR ${CMAKE_BINARY_DIR}/picolibc-install-${TARGET})
+set(PICOLIBC_CROSS_FILE ${CMAKE_BINARY_DIR}/picolibc-cross-file-${TARGET}.txt)
+
+
+# Generate the Meson cross-file
+configure_file(${CMAKE_CURRENT_LIST_DIR}/../scripts/picolibc-cross-file.txt.in ${PICOLIBC_CROSS_FILE} @ONLY)
+
+message(STATUS "[CHIMERA-SDK] Saving cross compilation file to ${PICOLIBC_CROSS_FILE}")
+# Add picolibc as an external project
+ExternalProject_Add(
+    picolibc-${TARGET}
+    GIT_REPOSITORY https://github.com/picolibc/picolibc.git
+    GIT_TAG main
+    SOURCE_DIR ${PICOLIBC_SRC_DIR}
+    BINARY_DIR ${PICOLIBC_BUILD_DIR}
+    INSTALL_DIR ${PICOLIBC_INSTALL_DIR}
+    CONFIGURE_COMMAND meson setup ${PICOLIBC_BUILD_DIR} ${PICOLIBC_SRC_DIR} --cross-file ${PICOLIBC_CROSS_FILE} --prefix ${PICOLIBC_INSTALL_DIR} --default-library=static
+    BUILD_COMMAND ninja -C ${PICOLIBC_BUILD_DIR}
+    INSTALL_COMMAND ninja -C ${PICOLIBC_BUILD_DIR} install
+)
+
+set(PICOLIBC_INSTALL_DIR ${PICOLIBC_INSTALL_DIR} PARENT_SCOPE)
+set(PICOLIBC_TARGET picolibc-${TARGET} PARENT_SCOPE)
+
+add_library(picolibc STATIC IMPORTED GLOBAL)
+
+set_target_properties(picolibc PROPERTIES
+    IMPORTED_LOCATION "${PICOLIBC_INSTALL_DIR}/lib/libc.a"
+)
+
+add_dependencies(picolibc picolibc-${TARGET})

drivers/uart_opentitan/CMakeLists.txt

@@ -24,6 +24,18 @@ set(OPENTITAN_SPARSE_PATTERNS
   "sw/device/lib/base/math_builtins.c"
   "sw/device/lib/base/memory.c"
   "sw/device/lib/base/memory.h"
+  "sw/device/lib/base/mmio.c"
+  "sw/device/lib/base/mmio.h"
+  "sw/device/lib/base/multibits.c"
+  "sw/device/lib/base/multibits.h"
+  "sw/device/lib/base/internal/status.h"
+  "sw/device/lib/base/internal/absl_status.h"
+  "sw/device/lib/dif/dif_base.c"
+  "sw/device/lib/dif/dif_base.h"
+  "sw/device/lib/dif/dif_uart.c"
+  "sw/device/lib/dif/dif_uart.h"
+  "sw/device/lib/dif/autogen/dif_uart_autogen.c"
+  "sw/device/lib/dif/autogen/dif_uart_autogen.h"
 )
 
 # ------------------------------------------------------------------------------
@@ -55,13 +67,35 @@ add_custom_command(
   COMMENT "Generating ${UART_REGS_H} with COMMAND ${Python3_EXECUTABLE} ${REGTOOL_PY} ${UART_HJSON} -D > ${UART_REGS_H}"
 )
 
-message(STATUS "[REMOVE ME] COMMAND: ${Python3_EXECUTABLE} ${REGTOOL_PY} ${UART_HJSON} -D > ${UART_REGS_H}")
-
 # Generate the uart_regs.h header using the OT regtool
 add_custom_target(
   generate_uart_regs
   ALL
   DEPENDS "${UART_REGS_H}"
 )
 
-add_dependencies(generate_uart_regs opentitan_interface_${OPENTITAN_COMMIT_HASH})
+add_dependencies(generate_uart_regs opentitan_interface_${OPENTITAN_COMMIT_HASH})
+
+# ------------------------------------------------------------------------------
+# Add the UART driver library
+# ------------------------------------------------------------------------------
+add_library(uart_lib STATIC)
+
+file(GLOB_RECURSE UART_SOURCES
+  "${OPENTITAN_SW_DIR}/device/lib/base/*.c"
+  "${OPENTITAN_SW_DIR}/device/lib/dif/*.c"
+)
+
+target_sources(
+  uart_lib
+  PRIVATE
+    ${UART_SOURCES}
+    ${UART_REGS_H}
+)
+
+target_include_directories(
+  uart_lib
+  PUBLIC
+  ${OPENTITAN_DIR}
+  ${OPENTITAN_SW_DIR}/device/lib/dif/autogen
+)

hal/CMakeLists.txt

@@ -14,3 +14,9 @@ target_include_directories(hal_host
   PUBLIC
   "inc/"
 )
+
+target_link_libraries(hal_host
+  PUBLIC
+    uart_lib
+    picolibc
+)

hal/inc/device_api.h

@@ -6,12 +6,32 @@
 
 #include <stdint.h>
 #include <stdio.h>
+#include <stdbool.h>
 
 /**
  * \addtogroup device
  * @{
  */
 
+/**
+ * @brief Device structure.
+ *
+ */
+typedef struct chi_device {
+    /**
+     * @brief Device API.
+     */
+    struct chi_device_api *api; // function pointers
+    /**
+     * @brief Device address.
+     */
+    uint32_t *device_addr;
+    /**
+     * @brief Device configuration.
+     */
+    void *cfg;
+} chi_device_t;
+
 /**
  * @brief Callback function for asynchronous device operations.
  *
@@ -59,23 +79,4 @@ typedef struct chi_device_api {
                            chi_device_callback cb);
 } chi_device_api_t;
 
-/**
- * @brief Device structure.
- *
- */
-typedef struct chi_device {
-    /**
-     * @brief Device API.
-     */
-    struct chi_device_api *api; // function pointers
-    /**
-     * @brief Device address.
-     */
-    uint32_t *device_addr;
-    /**
-     * @brief Device configuration.
-     */
-    void *cfg;
-} chi_device_t;
-
 /** @} */

hal/inc/uart.h

@@ -0,0 +1,67 @@
+// Copyright 2024 ETH Zurich and University of Bologna.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+//
+// Viviane Potcnik <[email protected]>
+
+#ifndef UART_H
+#define UART_H
+
+#include <stdint.h>
+#include "device_api.h"
+#include "sw/device/lib/base/mmio.h"
+#include "sw/device/lib/dif/dif_uart.h"
+#include "uart_regs.h"
+#include <stddef.h>
+#include <stdlib.h>
+
+// Parity options
+#define UART_PARITY_NONE 0
+#define UART_PARITY_EVEN 1
+#define UART_PARITY_ODD  2
+
+// Default UART configurations (can be overridden via compiler defines)
+#ifndef UART_DEFAULT_BAUD_RATE
+#define UART_DEFAULT_BAUD_RATE 115200
+#endif
+
+#ifndef UART_DEFAULT_DATA_BITS
+#define UART_DEFAULT_DATA_BITS 8
+#endif
+
+#ifndef UART_DEFAULT_PARITY
+#define UART_DEFAULT_PARITY UART_PARITY_NONE
+#endif
+
+#ifndef UART_DEFAULT_STOP_BITS
+#define UART_DEFAULT_STOP_BITS 1
+#endif
+
+#ifndef UART_CLK_FREQ_HZ
+#define UART_CLK_FREQ_HZ 100000000
+#endif
+
+#ifndef UART_BASE_ADDR
+#define UART_BASE_ADDR 0x40000000
+#endif
+
+// UART configuration structure
+typedef struct {
+    uint32_t baud_rate;
+    uint32_t clk_freq_hz;
+    uint8_t data_bits;
+    uint8_t parity;
+    uint8_t stop_bits;
+} uart_config_t;
+
+// Function declarations
+int uart_open(struct chi_device *device);
+int uart_close(struct chi_device *device);
+ssize_t uart_read_async(struct chi_device *device, void *buffer, uint32_t size, chi_device_callback cb);
+ssize_t uart_write_async(struct chi_device *device, const void *buffer, uint32_t size, chi_device_callback cb);
+
+// Extern the UART API structure
+extern struct chi_device_api uart_api;
+extern uart_config_t default_cfg;
+
+#endif // UART_H

hal/src/uart.c

@@ -0,0 +1,91 @@
+// Copyright 2024 ETH Zurich and University of Bologna.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+//
+// Viviane Potcnik <[email protected]>
+
+#include "uart.h"
+
+// Define the UART API structure
+struct chi_device_api uart_api = {
+    .open = uart_open,
+    .close = uart_close,
+    .read_async = uart_read_async,
+    .write_async = uart_write_async
+};
+
+// UART context structure
+typedef struct uart_context {
+    dif_uart_t uart; // UART DIF handle
+    // Asynchronous read state
+    uint8_t *rx_buffer;
+    uint32_t rx_size;
+    uint32_t rx_pos;
+    chi_device_callback rx_callback;
+    // Asynchronous write state
+    const uint8_t *tx_buffer;
+    uint32_t tx_size;
+    uint32_t tx_pos;
+    chi_device_callback tx_callback;
+} uart_context_t;
+
+// Default UART configuration
+uart_config_t default_cfg = {
+    .baud_rate = UART_DEFAULT_BAUD_RATE,
+    .clk_freq_hz = UART_CLK_FREQ_HZ,
+    .data_bits = UART_DEFAULT_DATA_BITS,
+    .parity    = UART_DEFAULT_PARITY,
+    .stop_bits = UART_DEFAULT_STOP_BITS
+};
+
+int uart_open(struct chi_device *device) {
+
+    // Check if the device and device address are valid
+    if (device == NULL || device->device_addr == NULL) {
+        return -1; // Invalid argument
+    }
+
+    // Initialize the UART context
+    uart_context_t *ctx = malloc(sizeof(uart_context_t));
+    if (ctx == NULL) {
+        return -2; // Out of memory error
+    }
+    memset(ctx, 0, sizeof(uart_context_t));
+
+    // // If no cfg is provided, use the default configuration
+    // uart_config_t *cfg = device->cfg;
+    // if (cfg == NULL) {
+    //     cfg = &default_cfg;
+    // }
+
+    // free(ctx); // Free the UART context
+
+    return 0; // Success
+}
+
+int uart_close(struct chi_device *device) {
+
+    if (device == NULL || device->cfg == NULL) {
+        return -1; // Invalid argument
+    }
+
+    return 0; // Success
+}
+
+ssize_t uart_read_async(struct chi_device *device, void *buffer, uint32_t size, chi_device_callback cb) {
+
+    if (device == NULL || device->cfg == NULL || buffer == NULL || size == 0) {
+        return -1; // Invalid argument
+    }
+
+    return size; // Return the number of bytes to be read
+}
+
+ssize_t uart_write_async(struct chi_device *device, const void *buffer, uint32_t size, chi_device_callback cb) {
+
+    if (device == NULL || device->cfg == NULL || buffer == NULL || size == 0) {
+        return -1; // Invalid argument
+    }
+
+    return size; // Return the number of bytes to be written
+}

scripts/picolibc-cross-file.txt.in

@@ -0,0 +1,19 @@
+# Copyright 2024 ETH Zurich and University of Bologna.
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+
+[binaries]
+c = [ '@CROSS_C_COMPILER@', @CROSS_C_COMPILER_ARGS_LIST@ ]
+ar = '@CROSS_AR@'
+strip = '@CROSS_STRIP@'
+
+[host_machine]
+system = '@CROSS_SYSTEM@'
+cpu_family = '@CROSS_CPU_FAMILY@'
+cpu = '@CROSS_CPU@'
+endian = '@CROSS_ENDIAN@'
+
+[properties]
+c_args = [ @CROSS_C_ARGS_LIST@ ]
+c_link_args = [ @CROSS_C_LINK_ARGS_LIST@ ]
+skip_sanity_check = @CROSS_SKIP_SANITY_CHECK@