Use CONFIG_CONSOLE_MUX for netconsole. When netconsole is running, stdin/stdout/stder must be set to some primary console, in addtion to nc. For example, stdin=serial,nc. Some recent Linux kernels will not boot with only nc on the stdout list, ie. stdout=nc. When netconsole exits, remove nc from the list of devices in stdin/stdout/stderr.
Signed-off-by: Tony Dinh mibodhi@gmail.com ---
Changes in v2: - Select CONFIG_CONSOLE_MUX if CONFIG_NETCONSOLE is enabled - Add new functions in netconsole driver to support CONSOLE_MUX - Add new function to encapsulate the process of stopping netconsole from bootm - Remove unecessary net_timeout initial value = 1
boot/bootm.c | 13 ++++++--- drivers/net/Kconfig | 10 +++++++ drivers/net/netconsole.c | 60 ++++++++++++++++++++++++++++++++++++++++ include/stdio_dev.h | 1 + 4 files changed, 80 insertions(+), 4 deletions(-)
diff --git a/boot/bootm.c b/boot/bootm.c index 2eec60ec7b..11203c01ec 100644 --- a/boot/bootm.c +++ b/boot/bootm.c @@ -472,11 +472,16 @@ ulong bootm_disable_interrupts(void) * recover from any failures any more... */ iflag = disable_interrupts(); -#ifdef CONFIG_NETCONSOLE - /* Stop the ethernet stack if NetConsole could have left it up */ - eth_halt(); -#endif
+ if (IS_ENABLED(CONFIG_NETCONSOLE)) { + /* + * Make sure that the starting kernel message printed out, + * stop netconsole and the ethernet stack + */ + printf("\n\nStarting kernel ...\n\n"); + drv_nc_stop(); + eth_halt(); + } #if defined(CONFIG_CMD_USB) /* * turn off USB to prevent the host controller from writing to the diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index ceadee98a1..0661059dfa 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -945,4 +945,14 @@ config MDIO_MUX_MESON_G12A This driver is used for the MDIO mux found on the Amlogic G12A & compatible SoCs.
+config NETCONSOLE + bool "Enable netconsole" + select CONSOLE_MUX + help + NetConsole requires CONSOLE_MUX, i.e. at least one default console such + must be specified in addition to nc console. For example, for boards that + the main console is serial, set each of the envs stdin/stdout/stderr to serial,nc. + See CONFIG_CONSOLE_MUX and CONFIG_SYS_CONSOLE_IS_IN_ENV help for detailed + description of usage. + endif # NETDEVICES diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 151bc55e07..bb92d2e130 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -7,6 +7,7 @@ #include <common.h> #include <command.h> #include <env.h> +#include <iomux.h> #include <log.h> #include <stdio_dev.h> #include <net.h> @@ -33,6 +34,12 @@ static int output_packet_len; */ enum proto_t net_loop_last_protocol = BOOTP;
+/* + * Net console helpers + */ +static void usage(void); +static void remove_nc_from(const int console); + static void nc_wait_arp_handler(uchar *pkt, unsigned dest, struct in_addr sip, unsigned src, unsigned len) @@ -111,6 +118,21 @@ static int refresh_settings_from_env(void) return 0; }
+static void remove_nc_from(const int console) +{ + int ret; + + ret = iomux_replace_device(console, "nc", "nulldev"); + if (ret) { + printf("\n*** Warning: Cannot remove nc from %s Error=%d\n", + stdio_names[console], ret); + printf("%s=", stdio_names[console]); + iomux_printdevs(console); + usage(); + flush(); + } +} + /** * Called from net_loop in net/net.c before each packet */ @@ -241,6 +263,29 @@ static int nc_stdio_start(struct stdio_dev *dev) return 0; }
+void nc_stdio_stop(void) +{ + if (IS_ENABLED(CONFIG_CONSOLE_MUX)) { + int ret; + struct stdio_dev *sdev; + + /* Remove nc from each stdio file */ + remove_nc_from(stdin); + remove_nc_from(stderr); + remove_nc_from(stdout); + + /* Deregister nc device */ + sdev = stdio_get_by_name("nc"); + ret = stdio_deregister_dev(sdev, true); + if (ret) + printf("\nWarning: Cannot deregister nc console Error=%d\n", ret); + } else { + printf("\n*** Warning: CONFIG_CONSOLE_MUX must be enabled for netconsole\n" + "to work properly. The nc console will be removed when\n" + "netconsole driver stops\n"); + } +} + static void nc_stdio_putc(struct stdio_dev *dev, char c) { if (output_recursion) @@ -316,6 +361,16 @@ static int nc_stdio_tstc(struct stdio_dev *dev) return input_size != 0; }
+static void usage(void) +{ + printf("USAGE:\n" + "NetConsole requires CONFIG_CONSOLE_MUX. At least one default console\n" + "must be specified in addition to nc console. For example, for boards\n" + "that the main console is serial, set the each of envs stdin/stdout/stderr\n" + "to serial,nc. Some kernel might fail to boot when nc is the only device in\n" + "stdout list\n"); +} + int drv_nc_init(void) { struct stdio_dev dev; @@ -335,3 +390,8 @@ int drv_nc_init(void)
return (rc == 0) ? 1 : rc; } + +void drv_nc_stop(void) +{ + nc_stdio_stop(); +} diff --git a/include/stdio_dev.h b/include/stdio_dev.h index 3105928970..9d2375a67e 100644 --- a/include/stdio_dev.h +++ b/include/stdio_dev.h @@ -112,6 +112,7 @@ int drv_keyboard_init(void); int drv_usbtty_init(void); int drv_usbacm_init(void); int drv_nc_init(void); +void drv_nc_stop(void); int drv_jtag_console_init(void); int cbmemc_init(void);