This command allows to start CDC ACM function and redirect console
(stdin, stdout, stderr) to USB (acmconsole start). The console can
then be accessed through the USB host for debugging purpose. The
host can stop the session (acmconsole stop) to revert back console
to serial and unregister CDC ACM USB function.
Signed-off-by: Loic Poulain <loic.poul...@linaro.org>
---
cmd/Kconfig | 8 ++++++++
cmd/Makefile | 2 ++
cmd/acmconsole.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 60 insertions(+)
create mode 100644 cmd/acmconsole.c
diff --git a/cmd/Kconfig b/cmd/Kconfig
index ffef3cc..7cc9b1c 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1382,6 +1382,14 @@ config CMD_AXI
Interface) busses, a on-chip interconnect specification for managing
functional blocks in SoC designs, which is also often used in designs
involving FPGAs (e.g. communication with IP cores in Xilinx FPGAs).
+
+config CMD_USB_ACM_CONSOLE
+ bool "ACM USB console"
+ select USB_FUNCTION_ACM
+ help
+ Enable the command "acmconsole" for accessing u-boot console from a
+ USB host through CDC ACM protocol.
+
endmenu
diff --git a/cmd/Makefile b/cmd/Makefile
index ed36694..c116091 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_CMD_BOOTMENU) += bootmenu.o
obj-$(CONFIG_CMD_BOOTSTAGE) += bootstage.o
obj-$(CONFIG_CMD_BOOTZ) += bootz.o
obj-$(CONFIG_CMD_BOOTI) += booti.o
+ob-y += acmconsole.o
obj-$(CONFIG_CMD_BTRFS) += btrfs.o
obj-$(CONFIG_CMD_BUTTON) += button.o
obj-$(CONFIG_CMD_CACHE) += cache.o
@@ -174,6 +175,7 @@ obj-$(CONFIG_CMD_FS_UUID) += fs_uuid.o
obj-$(CONFIG_CMD_USB_MASS_STORAGE) += usb_mass_storage.o
obj-$(CONFIG_CMD_USB_SDP) += usb_gadget_sdp.o
obj-$(CONFIG_CMD_THOR_DOWNLOAD) += thordown.o
+obj-$(CONFIG_CMD_USB_ACM_CONSOLE) += acmconsole.o
obj-$(CONFIG_CMD_XIMG) += ximg.o
obj-$(CONFIG_CMD_YAFFS2) += yaffs2.o
obj-$(CONFIG_CMD_SPL) += spl.o
diff --git a/cmd/acmconsole.c b/cmd/acmconsole.c
new file mode 100644
index 0000000..dac8136
--- /dev/null
+++ b/cmd/acmconsole.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * acmconsole.c -- Console over USB CDC serial (ACM) function gadget function
+ *
+ * Copyright (c) 2021, Linaro Ltd <loic.poul...@linaro.org>
+ */
+
+#include <common.h>
+#include <console.h>
+#include <dfu.h>
+#include <g_dnl.h>
+#include <stdio_dev.h>
+#include <usb.h>
+#include <watchdog.h>
+
+int do_usb_acmconsole(cmd_tbl_t *cmdtp, int flag, int argc, char * const
argv[])
+{
+ int ret;
+
+ if (argc != 2)
+ return CMD_RET_USAGE;
+
+ if (!strcmp(argv[1], "start")) {
+ ret = g_dnl_register("usb_serial_acm");
+ if (ret)
+ return ret;
+
+ /* ACM function creates a stdio device name 'stdio_acm' */
+ console_assign(stdin, "stdio_acm");
+ console_assign(stdout, "stdio_acm");
+ console_assign(stderr, "stdio_acm");
+ } else if (!strcmp(argv[1], "stop")) {
+ /* default to serial (TODO: restore initial devices) */
+ console_assign(stdin, "serial");
+ console_assign(stdout, "serial");
+ console_assign(stderr, "serial");
+
+ g_dnl_unregister();
+ g_dnl_clear_detach();
+ } else {
+ return CMD_RET_USAGE;
+ }
+
+ return 0;
+}
+
+U_BOOT_CMD(acmconsole, CONFIG_SYS_MAXARGS, 1, do_usb_acmconsole,
+ "Console over USB CDC ACM",
+ "start - start console over USB CDC ACM gadget function\n" \
+ "acmconsole stop - stop USB console");
--
2.7.4
