shell: add devmem load command

This commit adds a devmem load command for shell that allows
users to easily load arbitrary data into the device memory.

Signed-off-by: Mateusz Sierszulski <msierszulski@internships.antmicro.com>
Signed-off-by: Tomasz Gorochowik <tgorochowik@antmicro.com>

samples/subsys/shell/devmem_load/CMakeLists.txt

@@ -0,0 +1,8 @@
+# Copyright (c) 2021 Antmicro <www.antmicro.com>
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.13.1)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(devmem_load)
+
+target_sources(app PRIVATE src/main.c)

samples/subsys/shell/devmem_load/README.md

@@ -0,0 +1,53 @@
+# Zephyr devmem load command
+This module add a `devmem load` command that allows data to be loaded into device memory.
+The `devmem load` command is supported by every transport the shell can run on.
+
+After using a command in the Zephyr shell, the device reads all transferred data and writes to an address in the memory.
+The transfer ends when the user presses `ctrl-x + ctrl-q`.
+
+## Usage
+Note: when using the devmem load command over UART it is recommended to use interrupts whenever possible.
+If this is not possible, reduce the baud rate to 9600.
+
+If you use poll you should also use `prj_poll.conf` instead of `prj.conf`.
+## Building
+
+The sample can be built for several platforms, the following commands build and run the application with a shell for the FRDM-K64F board.
+```bash
+west build -b frdm_k64f samples/subsys/shell/devmem_load
+west flash
+```
+
+Building for boards without UART interrupt support:
+```bash
+west build -b quick_feather -- -DOVERLAY_CONFIG=prj_poll.conf  samples/subsys/shell/devmem_load
+west flash
+```
+## Running
+After connecting to the UART console you should see the following output:
+```bash
+uart:~$
+```
+The `devmem load` command can now be used (`devmem load [option] [address]`):
+```bash
+uart:~$ devmem load 0x20020000
+Loading...
+press ctrl-x ctrl-q to escape
+```
+
+Now, the `devmem load` is waiting for data.
+You can either type it directly from the console or send it from the host PC (replace `ttyX` with the appropriate one for your UART console):
+```bash
+xxd -p data > /dev/ttyX
+```
+(It is important to use plain-style hex dump)
+Once the data is transferred, use `ctrl-x + ctrl-q` to quit the loader.
+It will print the number of the bytes read and return to the shell:
+```bash
+Number of bytes read: 3442
+uart:~$
+```
+
+## Options
+Currently, the `devmem load` command supports the following argument:
+* `-e` little endian parse e.g. `0xDEADBEFF -> 0xFFBEADDE`

samples/subsys/shell/devmem_load/prj.conf

@@ -0,0 +1,2 @@
+CONFIG_BOOT_BANNER=n
+CONFIG_SHELL=y

samples/subsys/shell/devmem_load/prj_poll.conf

@@ -0,0 +1,4 @@
+CONFIG_SHELL=y
+CONFIG_SHELL_BACKEND_SERIAL_INTERRUPT_DRIVEN=n
+CONFIG_SHELL_BACKEND_SERIAL_RX_POLL_PERIOD=1
+CONFIG_BOOT_BANNER=n

samples/subsys/shell/devmem_load/src/main.c

@@ -0,0 +1,10 @@
+/*
+ * Copyright (c) 2021 Antmicro <www.antmicro.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+void main(void)
+{
+
+};

subsys/shell/modules/devmem_service.c

@@ -1,12 +1,137 @@
 /*
  * Copyright (c) 2020 Intel Corporation
+ * Copyright (c) 2021 Antmicro <www.antmicro.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#include <stdlib.h>
 #include <device.h>
 #include <shell/shell.h>
-#include <stdlib.h>
+#include <sys/byteorder.h>
+
+static inline bool is_ascii(uint8_t data)
+{
+	return (data >= 0x30 && data <= 0x39) || (data >= 0x61 && data <= 0x66) ||
+	       (data >= 0x41 && data <= 0x46);
+}
+
+static unsigned char *bytes;
+static uint32_t *data;
+static int sum;
+static int chunk_element;
+static char chunk[2];
+static bool littleendian;
+
+#define CHAR_CAN 0x18
+#define CHAR_DC1 0x11
+
+static int set_bypass(const struct shell *sh, shell_bypass_cb_t bypass)
+{
+	static bool in_use;
+
+	if (bypass && in_use) {
+		shell_error(sh, "devmem load supports setting bypass on a single instance.");
+
+		return -EBUSY;
+	}
+
+	in_use = !in_use;
+	if (in_use) {
+		shell_print(sh, "Loading...\npress ctrl-x ctrl-q to escape");
+		in_use = true;
+	}
+
+	shell_set_bypass(sh, bypass);
+
+	return 0;
+}
+
+static void bypass_cb(const struct shell *sh, uint8_t *recv, size_t len)
+{
+	bool escape = false;
+	static uint8_t tail;
+	uint8_t byte;
+
+	if (tail == CHAR_CAN && recv[0] == CHAR_DC1) {
+		escape = true;
+	} else {
+		for (int i = 0; i < (len - 1); i++) {
+			if (recv[i] == CHAR_CAN && recv[i + 1] == CHAR_DC1) {
+				escape = true;
+				break;
+			}
+		}
+	}
+
+	if (escape) {
+		shell_print(sh, "Number of bytes read: %d", sum);
+		set_bypass(sh, NULL);
+
+		if (!littleendian) {
+			while (sum > 4) {
+				*data = __bswap_32(*data);
+				data++;
+				sum = sum - 4;
+			}
+			if (sum % 4 == 0) {
+				*data = __bswap_32(*data);
+			} else if (sum % 4 == 2) {
+				*data = __bswap_16(*data);
+			} else if (sum % 4 == 3) {
+				*data = __bswap_24(*data);
+			}
+		}
+		return;
+	}
+
+	tail = recv[len - 1];
+
+	if (is_ascii(*recv)) {
+		chunk[chunk_element] = *recv;
+		chunk_element++;
+	}
+
+	if (chunk_element == 2) {
+		byte = (uint8_t)strtoul(chunk, NULL, 16);
+		*bytes = byte;
+		bytes++;
+		sum++;
+		chunk_element = 0;
+	}
+}
+
+static int cmd_load(const struct shell *sh, size_t argc, char **argv)
+{
+	littleendian = false;
+	char *arg;
+
+	chunk_element = 0;
+	sum = 0;
+
+	while (argc >= 2) {
+		arg = argv[1] + (!strncmp(argv[1], "--", 2) && argv[1][2]);
+		if (!strncmp(arg, "-e", 2)) {
+			littleendian = true;
+		} else if (!strcmp(arg, "--")) {
+			argv++;
+			argc--;
+			break;
+		} else if (arg[0] == '-' && arg[1]) {
+			shell_print(sh, "Unknown option \"%s\"", arg);
+		} else {
+			break;
+		}
+		argv++;
+		argc--;
+	}
+
+	bytes = (unsigned char *)strtol(argv[1], NULL, 0);
+	data = (uint32_t *)strtol(argv[1], NULL, 0);
+
+	set_bypass(sh, bypass_cb);
+	return 0;
+}
 
 static int memory_read(const struct shell *sh, mem_addr_t addr, uint8_t width)
 {
@@ -36,8 +161,7 @@ static int memory_read(const struct shell *sh, mem_addr_t addr, uint8_t width)
 	return err;
 }
 
-static int memory_write(const struct shell *sh, mem_addr_t addr,
-			uint8_t width, uint64_t value)
+static int memory_write(const struct shell *sh, mem_addr_t addr, uint8_t width, uint64_t value)
 {
 	int err = 0;
 
@@ -104,5 +228,16 @@ static int cmd_devmem(const struct shell *sh, size_t argc, char **argv)
 	return memory_write(sh, addr, width, value);
 }
 
-SHELL_CMD_REGISTER(devmem, NULL, "Read/write physical memory\""
-		   "devmem address [width [value]]", cmd_devmem);
+SHELL_STATIC_SUBCMD_SET_CREATE(sub_devmem,
+			       SHELL_CMD_ARG(load, NULL,
+					     "Usage:\n"
+					     "devmem load [options] [address]\n"
+					     "Options:\n"
+					     "-e\tlittle-endian parse",
+					     cmd_load, 2, 1),
+			       SHELL_SUBCMD_SET_END);
+
+SHELL_CMD_REGISTER(devmem, &sub_devmem,
+		   "Read/write physical memory\""
+		   "devmem address [width [value]]",
+		   cmd_devmem);