diff --git a/components/vfs/CMakeLists.txt b/components/vfs/CMakeLists.txt index 77083dc20..6089473ee 100644 --- a/components/vfs/CMakeLists.txt +++ b/components/vfs/CMakeLists.txt @@ -1,5 +1,6 @@ set(COMPONENT_SRCS "vfs.c" - "vfs_uart.c") + "vfs_uart.c" + "vfs_semihost.c") set(COMPONENT_ADD_INCLUDEDIRS "include") set(COMPONENT_REQUIRES) diff --git a/components/vfs/Kconfig b/components/vfs/Kconfig index c479a989e..b34679b20 100644 --- a/components/vfs/Kconfig +++ b/components/vfs/Kconfig @@ -15,4 +15,20 @@ menu "Virtual file system" help Disabling this option can save memory when the support for termios.h is not required. + menu "Host File System I/O (Semihosting)" + config SEMIHOSTFS_MAX_MOUNT_POINTS + int "Maximum number of the host filesystem mount points" + default 1 + help + Define maximum number of host filesystem mount points. + + config SEMIHOSTFS_HOST_PATH_MAX_LEN + int "Maximum path length for the host base directory" + default 128 + help + Define maximum path length for the host base directory which is to be mounted. + If host path passed to esp_vfs_semihost_register() is longer than this value + it will be truncated. + endmenu + endmenu diff --git a/components/vfs/include/esp_vfs_semihost.h b/components/vfs/include/esp_vfs_semihost.h new file mode 100644 index 000000000..20a0ed550 --- /dev/null +++ b/components/vfs/include/esp_vfs_semihost.h @@ -0,0 +1,46 @@ +// Copyright 2019 Espressif Systems (Shanghai) PTE LTD +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#pragma once + +#include "esp_vfs.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @brief add virtual filesystem semihosting driver + * + * @param base_path VFS path to mount host directory + * @param host_path host path to mount; if NULL default dirctory will be used (see OpenOCD configuration) + * @return + * - ESP_OK on success + * - ESP_ERR_INVALID_ARG if esp_vfs_semihost_register was already called for specified VFS path + * - ESP_ERR_NO_MEM if there are no slots to register new mount point + */ +esp_err_t esp_vfs_semihost_register(const char* base_path, const char* host_path); + +/** + * @brief Un-register semihosting driver from VFS + * + * @return + * - ESP_OK on success + * - ESP_ERR_INVALID_ARG if semihosting driver is not registered in VFS at that path + */ +esp_err_t esp_vfs_semihost_unregister(const char* base_path); + +#ifdef __cplusplus +} +#endif diff --git a/components/vfs/vfs_semihost.c b/components/vfs/vfs_semihost.c new file mode 100644 index 000000000..d97fa9188 --- /dev/null +++ b/components/vfs/vfs_semihost.c @@ -0,0 +1,216 @@ +// Copyright 2019 Espressif Systems (Shanghai) PTE LTD +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include +#include +#include +#include +#include +#include +#include "soc/cpu.h" +#include "freertos/FreeRTOS.h" +#include "freertos/task.h" +#include "esp_vfs.h" + +#define LOG_LOCAL_LEVEL ESP_LOG_NONE +#include "esp_log.h" +const static char *TAG = "esp_semihost"; + +#define SYSCALL_INSTR "break 1,1\n" +#define SYS_OPEN 0x01 +#define SYS_CLOSE 0x02 +#define SYS_WRITE 0x05 +#define SYS_READ 0x06 +#define SYS_SEEK 0x0A + +/** ESP-specific file open flag. Indicates that path passed to open() is absolute host path. */ +#define ESP_O_SEMIHOST_ABSPATH 0x80000000 + +typedef struct { + char base_path[ESP_VFS_PATH_MAX+1]; /* base path in VFS where host semohosting dir is mounted */ + char host_path[CONFIG_SEMIHOSTFS_HOST_PATH_MAX_LEN+1]; /* host path to use as base dir for open files */ +} vfs_semihost_ctx_t; + +static vfs_semihost_ctx_t s_semhost_ctx[CONFIG_SEMIHOSTFS_MAX_MOUNT_POINTS]; + + +static inline int generic_syscall(int sys_nr, int arg1, int arg2, int arg3, int arg4, int* ret_errno) +{ + int host_ret, host_errno; + + if (!esp_cpu_in_ocd_debug_mode()) { + *ret_errno = EIO; + return -1; + } + __asm__ volatile ( + "mov a2, %[sys_nr]\n" \ + "mov a3, %[arg1]\n" \ + "mov a4, %[arg2]\n" \ + "mov a5, %[arg3]\n" \ + "mov a6, %[arg4]\n" \ + SYSCALL_INSTR \ + "mov %[host_ret], a2\n" \ + "mov %[host_errno], a3\n" \ + :[host_ret]"=r"(host_ret),[host_errno]"=r"(host_errno) + :[sys_nr]"r"(sys_nr),[arg1]"r"(arg1),[arg2]"r"(arg2),[arg3]"r"(arg3),[arg4]"r"(arg4) + :"a2","a3","a4","a5","a6"); + *ret_errno = host_errno; + return host_ret; +} + +inline bool ctx_is_unused(const vfs_semihost_ctx_t* ctx) +{ + return ctx->base_path[0] == 0; +} + +inline bool ctx_uses_abspath(const vfs_semihost_ctx_t* ctx) +{ + return ctx->host_path[0]; +} + +static int vfs_semihost_open(void* ctx, const char * path, int flags, int mode) +{ + int fd = -1, host_err = 0; + char *host_path; + vfs_semihost_ctx_t *semi_ctx = ctx; + + ESP_LOGV(TAG, "%s: %p '%s 0x%x 0x%x'", __func__, semi_ctx, path, flags, mode); + if (ctx_uses_abspath(semi_ctx)) { + flags |= ESP_O_SEMIHOST_ABSPATH; + host_path = malloc(strlen(semi_ctx->host_path)+strlen(path)+1); + if(host_path == NULL) { + errno = ENOMEM; + return -1; + } + strcpy(host_path, semi_ctx->host_path); + strcat(host_path, path); + } else { + host_path = (char *)path; + } + fd = generic_syscall(SYS_OPEN, (int)host_path, strlen(host_path), flags, mode, &host_err); + if (ctx_uses_abspath(semi_ctx)) { + free(host_path); + } + if (fd == -1) { + errno = host_err; + } + return fd; +} + +static ssize_t vfs_semihost_write(void* ctx, int fd, const void * data, size_t size) +{ + int host_err = 0; + size_t ret = -1; + + ESP_LOGV(TAG, "%s: %d %u bytes", __func__, fd, size); + ret = generic_syscall(SYS_WRITE, fd, (int)data, size, 0, &host_err); + if (ret == -1) { + errno = host_err; + } + return (ssize_t)ret; +} + +static ssize_t vfs_semihost_read(void* ctx, int fd, void* data, size_t size) +{ + int host_err = 0; + size_t ret = -1; + + ESP_LOGV(TAG, "%s: %d %u bytes", __func__, fd, size); + ret = generic_syscall(SYS_READ, fd, (int)data, size, 0, &host_err); + if (ret == -1) { + errno = host_err; + } + return (ssize_t)ret; +} + +static int vfs_semihost_close(void* ctx, int fd) +{ + int ret = -1, host_err = 0; + + ESP_LOGV(TAG, "%s: %d", __func__, fd); + ret = generic_syscall(SYS_CLOSE, fd, 0, 0, 0, &host_err); + if (ret == -1) { + errno = host_err; + } + return ret; +} + +static off_t vfs_semihost_lseek(void* ctx, int fd, off_t size, int mode) +{ + int ret = -1, host_err = 0; + + ESP_LOGV(TAG, "%s: %d %ld %d", __func__, fd, size, mode); + ret = generic_syscall(SYS_SEEK, fd, size, mode, 0, &host_err); + if (ret == -1) { + errno = host_err; + } + return (off_t)ret; +} + +esp_err_t esp_vfs_semihost_register(const char* base_path, const char* host_path) +{ + const esp_vfs_t vfs = { + .flags = ESP_VFS_FLAG_CONTEXT_PTR, + .write_p = &vfs_semihost_write, + .open_p = &vfs_semihost_open, + .close_p = &vfs_semihost_close, + .read_p = &vfs_semihost_read, + .lseek_p = &vfs_semihost_lseek, + }; + ESP_LOGD(TAG, "Register semihosting driver '%s' -> '%s'", base_path, host_path ? host_path : "null"); + if (!esp_cpu_in_ocd_debug_mode()) { + ESP_LOGE(TAG, "OpenOCD is not connected!"); + return ESP_ERR_NOT_SUPPORTED; + } + int i = 0; + for (i = 0; i < CONFIG_SEMIHOSTFS_MAX_MOUNT_POINTS; i++) { + if (ctx_is_unused(&s_semhost_ctx[i])) { + break; + } + if (strcmp(base_path, s_semhost_ctx[i].base_path) == 0) { + return ESP_ERR_INVALID_STATE; + } + } + if (i == CONFIG_SEMIHOSTFS_MAX_MOUNT_POINTS) { + return ESP_ERR_NO_MEM; + } + strlcpy(s_semhost_ctx[i].base_path, base_path, sizeof(s_semhost_ctx[i].base_path) - 1); + if (host_path) { + strlcpy(s_semhost_ctx[i].host_path, host_path, sizeof(s_semhost_ctx[i].host_path) - 1); + } + ESP_LOGD(TAG, "Register semihosting driver %d %p", i, &s_semhost_ctx[i]); + return esp_vfs_register(base_path, &vfs, &s_semhost_ctx[i]); +} + +esp_err_t esp_vfs_semihost_unregister(const char* base_path) +{ + ESP_LOGD(TAG, "Unregister semihosting driver @ '%s'", base_path); + int i = 0; + for (i = 0; i < CONFIG_SEMIHOSTFS_MAX_MOUNT_POINTS; i++) { + if (s_semhost_ctx[i].base_path[0] != 0 && strcmp(base_path, s_semhost_ctx[i].base_path) == 0) { + break; + } + } + if (i == CONFIG_SEMIHOSTFS_MAX_MOUNT_POINTS) { + return ESP_ERR_INVALID_ARG; + } + esp_err_t ret = esp_vfs_unregister(s_semhost_ctx[i].base_path); + if (ret != ESP_OK) { + return ret; + } + s_semhost_ctx[i].base_path[0] = 0; + s_semhost_ctx[i].host_path[0] = 0; + ESP_LOGD(TAG, "Unregistered semihosting driver @ '%s'", base_path); + return ESP_OK; +} diff --git a/docs/Doxyfile b/docs/Doxyfile index b79aa3e2c..b88c6fc78 100644 --- a/docs/Doxyfile +++ b/docs/Doxyfile @@ -137,6 +137,7 @@ INPUT = \ ## Virtual Filesystem ../../components/vfs/include/esp_vfs.h \ ../../components/vfs/include/esp_vfs_dev.h \ + ../../components/vfs/include/esp_vfs_semihost.h \ ## FAT Filesystem ## NOTE: for two lines below header_file.inc is not used ../../components/fatfs/src/esp_vfs_fat.h \