Hi Tony, On Mon, 3 Apr 2023 at 15:42, Tony Dinh <mibo...@gmail.com> wrote: > > 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 <mibo...@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 > - Resend to correct missing <stdio_dev.h> include in bootm.c > > boot/bootm.c | 14 +++++++--- > drivers/net/Kconfig | 10 +++++++ > drivers/net/netconsole.c | 60 ++++++++++++++++++++++++++++++++++++++++ > include/stdio_dev.h | 1 + > 4 files changed, 81 insertions(+), 4 deletions(-)
This seems OK to me but for a few thoughts below. But can we use this opportunity to move this to driver model? The netconsole driver could be bound in eth_post_bind() and the code in netconsole.c converted to be a driver. I think that would be better than building on an out-of-date driver. > > diff --git a/boot/bootm.c b/boot/bootm.c > index 2eec60ec7b..1b2542b570 100644 > --- a/boot/bootm.c > +++ b/boot/bootm.c > @@ -18,6 +18,7 @@ > #include <malloc.h> > #include <mapmem.h> > #include <net.h> > +#include <stdio_dev.h> > #include <asm/cache.h> > #include <asm/global_data.h> > #include <asm/io.h> > @@ -472,11 +473,16 @@ 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"); How about creating a doc/ file with info about net console? This is a bit too much text to put in a user message. > +} > + > 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); Once this is a driver we won't need this. > int drv_jtag_console_init(void); > int cbmemc_init(void); Regards, Simon