Modifications to support console multiplexing. This is controlled using CONFIG_SYS_CONSOLE_MUX in the board configuration file.
This allows a user to specify multiple console devices in the environment with a command like this: setenv stdin serial,nc. As a result, the user can enter text on both the serial and netconsole interfaces.
All devices - stdin, stdout and stderr - can be set in this manner.
1) common/iomux.c and include/iomux.h contain the environment setting implementation. 2) doc/README.iomux contains a somewhat more detailed description. 3) The implementation in (1) is called from common/cmd_nvedit.c to handle setenv and from common/console.c to handle initialization of input/output devices at boot time. 4) common/console.c also contains the code needed to poll multiple console devices for input and send output to all devices registered for output. 5) include/common.h includes iomux.h and common/Makefile generates iomux.o when CONFIG_SYS_CONSOLE_MUX is set.
Signed-off-by: Gary Jennejohn garyj@denx.de --- common/Makefile | 1 + common/cmd_nvedit.c | 6 ++ common/console.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++ common/iomux.c | 170 +++++++++++++++++++++++++++++++++++++++++++++++++++ doc/README.iomux | 89 +++++++++++++++++++++++++++ include/common.h | 7 ++ include/iomux.h | 54 ++++++++++++++++ 7 files changed, 489 insertions(+), 0 deletions(-) create mode 100644 common/iomux.c create mode 100644 doc/README.iomux create mode 100644 include/iomux.h
diff --git a/common/Makefile b/common/Makefile index f00cbd9..0296a8a 100644 --- a/common/Makefile +++ b/common/Makefile @@ -156,6 +156,7 @@ COBJS-$(CONFIG_LYNXKDI) += lynxkdi.o COBJS-$(CONFIG_UPDATE_TFTP) += update.o COBJS-$(CONFIG_USB_KEYBOARD) += usb_kbd.o COBJS-$(CONFIG_DDR_SPD) += ddr_spd.o +COBJS-$(CONFIG_SYS_CONSOLE_MUX) += iomux.o
COBJS := $(sort $(COBJS-y)) SRCS := $(AOBJS:.o=.S) $(COBJS:.o=.c) diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c index d280cb0..7a49296 100644 --- a/common/cmd_nvedit.c +++ b/common/cmd_nvedit.c @@ -213,6 +213,11 @@ int _do_setenv (int flag, int argc, char *argv[]) return 1; }
+#ifdef CONFIG_SYS_CONSOLE_MUX + i = iomux_doenv(console, argv[2]); + if (i) + return i; +#else /* Try assigning specified device */ if (console_assign (console, argv[2]) < 0) return 1; @@ -221,6 +226,7 @@ int _do_setenv (int flag, int argc, char *argv[]) if (serial_assign (argv[2]) < 0) return 1; #endif +#endif /* CONFIG_SYS_CONSOLE_MUX */ }
/* diff --git a/common/console.c b/common/console.c index 6f0846f..c89020d 100644 --- a/common/console.c +++ b/common/console.c @@ -93,6 +93,73 @@ static int console_setfile (int file, device_t * dev) return error; }
+#if defined(CONFIG_SYS_CONSOLE_MUX) +/** Console I/O multiplexing *******************************************/ + +static device_t *tstcdev; +device_t **console_devices[MAX_FILES]; +int cd_count[MAX_FILES]; + +/* + * This depends on tstc() always being called before getc(). + * No attempt is made to demultiplex multiple input sources. + */ +static int iomux_getc(void) +{ + unsigned char ret; + + ret = tstcdev->getc(); + tstcdev = NULL; + return ret; +} + +static int iomux_tstc(int file) +{ + int i, ret; + device_t *dev; + + disable_ctrlc(1); + for (i = 0; i < cd_count[file]; i++) { + dev = console_devices[file][i]; + if (dev->tstc != NULL) { + ret = dev->tstc(); + if (ret > 0) { + tstcdev = dev; + disable_ctrlc(0); + return ret; + } + } + } + disable_ctrlc(0); + + return 0; +} + +static void iomux_putc(int file, const char c) +{ + int i; + device_t *dev; + + for (i = 0; i < cd_count[file]; i++) { + dev = console_devices[file][i]; + if (dev->putc != NULL) + dev->putc(c); + } +} + +static void iomux_puts(int file, const char *s) +{ + int i; + device_t *dev; + + for (i = 0; i < cd_count[file]; i++) { + dev = console_devices[file][i]; + if (dev->puts != NULL) + dev->puts(s); + } +} +#endif /* defined(CONFIG_SYS_CONSOLE_MUX) */ + /** U-Boot INITIAL CONSOLE-NOT COMPATIBLE FUNCTIONS *************************/
void serial_printf (const char *fmt, ...) @@ -115,7 +182,41 @@ void serial_printf (const char *fmt, ...) int fgetc (int file) { if (file < MAX_FILES) +#if defined(CONFIG_SYS_CONSOLE_MUX) + { + int cntr = 0; + + /* + * Effectively poll for input wherever it may be available. + */ + for (;;) { + /* + * Upper layer may have already called tstc() so + * check for that first. + */ + if (tstcdev != NULL) + return iomux_getc(); + iomux_tstc(file); + /* + * Even this is too slow for serial cut&paste due + * to the overhead of calling tstc() then getc(). + * It gets worse if nc is set as a console because + * nc_tstc() is rather slow. + * + * The idea behind this counter is to avoid calling + * the watchdog via udelay() too often. + * COUNT_TIL_UDELAY is defined in iomux.h and is just + * a guesstimate. + */ + if (cntr++ > COUNT_TIL_UDELAY) { + udelay(1); + cntr = 0; + } + } + } +#else return stdio_devices[file]->getc (); +#endif
return -1; } @@ -123,7 +224,11 @@ int fgetc (int file) int ftstc (int file) { if (file < MAX_FILES) +#if defined(CONFIG_SYS_CONSOLE_MUX) + return iomux_tstc(file); +#else return stdio_devices[file]->tstc (); +#endif
return -1; } @@ -131,13 +236,21 @@ int ftstc (int file) void fputc (int file, const char c) { if (file < MAX_FILES) +#if defined(CONFIG_SYS_CONSOLE_MUX) + iomux_putc(file, c); +#else stdio_devices[file]->putc (c); +#endif }
void fputs (int file, const char *s) { if (file < MAX_FILES) +#if defined(CONFIG_SYS_CONSOLE_MUX) + iomux_puts(file, s); +#else stdio_devices[file]->puts (s); +#endif }
void fprintf (int file, const char *fmt, ...) @@ -407,6 +520,9 @@ int console_init_r (void) #ifdef CONFIG_SYS_CONSOLE_ENV_OVERWRITE int i; #endif /* CONFIG_SYS_CONSOLE_ENV_OVERWRITE */ +#ifdef CONFIG_SYS_CONSOLE_MUX + int iomux_err = 0; +#endif
/* set default handlers at first */ gd->jt[XF_getc] = serial_getc; @@ -425,6 +541,14 @@ int console_init_r (void) inputdev = search_device (DEV_FLAGS_INPUT, stdinname); outputdev = search_device (DEV_FLAGS_OUTPUT, stdoutname); errdev = search_device (DEV_FLAGS_OUTPUT, stderrname); +#ifdef CONFIG_SYS_CONSOLE_MUX + iomux_err = iomux_doenv(stdin, stdinname); + iomux_err += iomux_doenv(stdout, stdoutname); + iomux_err += iomux_doenv(stderr, stderrname); + if (!iomux_err) + /* Successful, so skip all the code below. */ + goto done; +#endif } /* if the devices are overwritten or not found, use default device */ if (inputdev == NULL) { @@ -438,15 +562,34 @@ int console_init_r (void) } /* Initializes output console first */ if (outputdev != NULL) { +#ifdef CONFIG_SYS_CONSOLE_MUX + /* need to set a console if not done above. */ + iomux_doenv(stdout, outputdev->name); +#else console_setfile (stdout, outputdev); +#endif } if (errdev != NULL) { +#ifdef CONFIG_SYS_CONSOLE_MUX + /* need to set a console if not done above. */ + iomux_doenv(stderr, errdev->name); +#else console_setfile (stderr, errdev); +#endif } if (inputdev != NULL) { +#ifdef CONFIG_SYS_CONSOLE_MUX + /* need to set a console if not done above. */ + iomux_doenv(stdin, inputdev->name); +#else console_setfile (stdin, inputdev); +#endif }
+#ifdef CONFIG_SYS_CONSOLE_MUX +done: +#endif + gd->flags |= GD_FLG_DEVINIT; /* device initialization completed */
#ifndef CONFIG_SYS_CONSOLE_INFO_QUIET @@ -455,21 +598,33 @@ int console_init_r (void) if (stdio_devices[stdin] == NULL) { puts ("No input devices available!\n"); } else { +#ifdef CONFIG_SYS_CONSOLE_MUX + iomux_printdevs(stdin); +#else printf ("%s\n", stdio_devices[stdin]->name); +#endif }
puts ("Out: "); if (stdio_devices[stdout] == NULL) { puts ("No output devices available!\n"); } else { +#ifdef CONFIG_SYS_CONSOLE_MUX + iomux_printdevs(stdout); +#else printf ("%s\n", stdio_devices[stdout]->name); +#endif }
puts ("Err: "); if (stdio_devices[stderr] == NULL) { puts ("No error devices available!\n"); } else { +#ifdef CONFIG_SYS_CONSOLE_MUX + iomux_printdevs(stderr); +#else printf ("%s\n", stdio_devices[stderr]->name); +#endif } #endif /* CONFIG_SYS_CONSOLE_INFO_QUIET */
@@ -524,11 +679,18 @@ int console_init_r (void) if (outputdev != NULL) { console_setfile (stdout, outputdev); console_setfile (stderr, outputdev); +#ifdef CONFIG_SYS_CONSOLE_MUX + console_devices[stdout][0] = outputdev; + console_devices[stderr][0] = outputdev; +#endif }
/* Initializes input console */ if (inputdev != NULL) { console_setfile (stdin, inputdev); +#ifdef CONFIG_SYS_CONSOLE_MUX + console_devices[stdin][0] = inputdev; +#endif }
gd->flags |= GD_FLG_DEVINIT; /* device initialization completed */ diff --git a/common/iomux.c b/common/iomux.c new file mode 100644 index 0000000..b83bdb5 --- /dev/null +++ b/common/iomux.c @@ -0,0 +1,170 @@ +/* + * (C) Copyright 2008 + * Gary Jennejohn, DENX Software Engineering GmbH, garyj@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <serial.h> +#include <malloc.h> + +#ifdef CONFIG_SYS_CONSOLE_MUX +void iomux_printdevs(const int console) +{ + int i; + device_t *dev; + + for (i = 0; i < cd_count[console]; i++) { + dev = console_devices[console][i]; + serial_printf("%s ", dev->name); + } + serial_printf("\n"); +} + +/* This tries to preserve the old list if an error occurs. */ +int iomux_doenv(const int console, const char *arg) +{ + char *console_args, *temp, **start; + int i, j, io_flag, cs_idx; + device_t *dev; + device_t **cons_set; + +#ifdef CONFIG_SYS_CONSOLE_IS_IN_ENV + if (arg == NULL) + return 1; +#endif + + console_args = strdup(arg); + if (console_args == NULL) + return 1; + /* + * Check whether a comma separated list of devices was + * entered and count how many devices were entered. + * The array start[] has pointers to the beginning of + * each device name (up to MAX_CONSARGS devices). + * + * Have to do this twice - once to count the number of + * commas and then again to populate start. + */ + i = 0; + temp = console_args; + for (;;) { + temp = strchr(temp, ','); + if (temp != NULL) { + i++; + temp++; + continue; + } + /* There's always one entry more than the number of commas. */ + i++; + break; + } + start = (char **)malloc(i * sizeof(char *)); + if (start == NULL) { + free(console_args); + return 1; + } + i = 0; + start[0] = console_args; + for (;;) { + temp = strchr(start[i], ','); + if (temp != NULL) { + i++; + *temp = '\0'; + start[i] = temp + 1; + continue; + } + /* There's always one entry more than the number of commas. */ + i++; + break; + } + cons_set = (device_t **)calloc(1, i * sizeof(device_t *)); + if (cons_set == NULL) { + free(start); + free(console_args); + return 1; + } + + switch (console) { + case stdin: + io_flag = DEV_FLAGS_INPUT; + break; + case stdout: + case stderr: + io_flag = DEV_FLAGS_OUTPUT; + break; + default: + return 1; + } + + cs_idx = 0; + for (j = 0; j < i; j++) { + /* + * Check whether the device exists and is valid. + * console_assign() also calls search_device(), + * but I need the pointer to the device. + */ + dev = search_device(io_flag, start[j]); + if (dev == NULL) + continue; + /* + * Try assigning the specified device. + * This could screw up the console settings for apps. + */ + if (console_assign(console, start[j]) < 0) + continue; +#ifdef CONFIG_SERIAL_MULTI + /* + * This was taken from common/cmd_nvedit.c. + * This will never work because serial_assign() returns + * 1 upon error, not -1. + * This would almost always return an error anyway because + * serial_assign() expects the name of a serial device, like + * serial_smc, but the user generally only wants to set serial. + */ + if (serial_assign(start[j]) < 0) + continue; +#endif + cons_set[cs_idx++] = dev; + } + free(console_args); + free(start); + /* failed to set any console */ + if (cs_idx == 0) { + free(cons_set); + return 1; + } else { + /* Works even if console_devices[console] is NULL. */ + console_devices[console] = + (device_t **)realloc(console_devices[console], + cs_idx * sizeof(device_t *)); + if (console_devices[console] == NULL) { + free(cons_set); + return 1; + } + memcpy(console_devices[console], cons_set, cs_idx * + sizeof(device_t *)); + + cd_count[console] = cs_idx; + } + free(cons_set); + return 0; +} +#endif /* CONFIG_SYS_CONSOLE_MUX */ diff --git a/doc/README.iomux b/doc/README.iomux new file mode 100644 index 0000000..bff75fa --- /dev/null +++ b/doc/README.iomux @@ -0,0 +1,89 @@ +/* + * (C) Copyright 2008 + * Gary Jennejohn, DENX Software Engineering GmbH garyj@denx.de + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +U-Boot console multiplexing +=========================== + +HOW CONSOLE MULTIPLEXING WORKS +------------------------------ + +This functionality is controlled with CONFIG_SYS_CONSOLE_MUX in the board +configuration file. + +Two new files, common/iomux.c and include/iomux.h, contain the heart +of the environment setting implementation. + +The execution is then in common/cmd_nvedit.c and common/console.c. + +A user can use a comma-separated list of devices to set stdin, stdout +and stderr. For example: setenv stdin serial,nc. NOTE: No spaces +are allowed around the comma(s)! + +The length of the list is limited by malloc(), since the array used +is allocated and freed dynamically. + +It should be possible to specify any device which console_assign() +finds acceptable, but the code has only been tested with serial and +nc. + +The major change in common/console.c was to modify fgetc() to call +the iomux_tstc() routine in a for-loop. iomux_tstc() in turn calls +the tstc() routine for every registered device, but exits immediately +when one of them returns true. fgetc() then calls iomux_getc(), +which calls the correpsonding getc() routine. fgetc() hangs in +the for-loop until iomux_tstc() returns true and the input can be +retrieved. + +Thus, a user can type into any device registered for stdin. No effort +has been made to demulitplex simultaneous input from multiple stdin +devices. + +fputc() and fputs() have been modified to call iomux_putc() and +iomux_puts() respectively, which call the corresponding output +routines for every registered device. + +Thus, a user can see the ouput for any device registered for stdout +or stderr on all devices registered for stdout or stderr. As an +example, if stdin=serial,nc and stdout=serial,nc then all output +for serial, e.g. echos of input on serial, will appear on serial and nc. + +Just as with the old console code, this statement is still true: +If not defined in the environment, the first input device is assigned +to the 'stdin' file, the first output one to 'stdout' and 'stderr'. + +If CONFIG_SYS_CONSOLE_IS_IN_ENV is defined then multiple input/output +devices can be set at boot time if defined in the environment. + +CAVEATS +------- + +Note that common/iomux.c calls console_assign() for every registered +device as it is discovered. This means that the environment settings +for application consoles will be set to the last device in the list. + +The overhead associated with calling tstc() and then getc() means that +copy&paste will normally not work, even if serial is set as the only device +for stdin, stdout and stderr. + +Using nc as a stdin device results in even more overhead because nc_tstc() +is quite slow. diff --git a/include/common.h b/include/common.h index b8a654a..53cc297 100644 --- a/include/common.h +++ b/include/common.h @@ -675,6 +675,13 @@ void fputc(int file, const char c); int ftstc(int file); int fgetc(int file);
+/* + * CONSOLE multiplexing. + */ +#ifdef CONFIG_SYS_CONSOLE_MUX +#include <iomux.h> +#endif + int pcmcia_init (void);
#ifdef CONFIG_STATUS_LED diff --git a/include/iomux.h b/include/iomux.h new file mode 100644 index 0000000..75b66e2 --- /dev/null +++ b/include/iomux.h @@ -0,0 +1,54 @@ +/* + * (C) Copyright 2008 + * Gary Jennejohn, DENX Software Engineering GmbH, garyj@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + *This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#ifndef _IO_MUX_H +#define _IO_MUX_H + +#include <devices.h> + +/* + * Stuff required to support console multiplexing. + */ + +/* + * Avoid invoking WATCHDOG via udelay() on every pass through the loop + * in fgetc(). Note this is all based on guesswork. + */ +#define COUNT_TIL_UDELAY 10000 + +/* + * Pointers to devices used for each file type. Defined in console.c + * but storage is allocated in iomux.c. + */ +extern device_t **console_devices[MAX_FILES]; +/* + * The count of devices assigned to each FILE. Defined in console.c + * and populated in iomux.c. + */ +extern int cd_count[MAX_FILES]; + +int iomux_doenv(const int, const char *); +void iomux_printdevs(const int); +device_t *search_device(int, char *); + +#endif /* _IO_MUX_H */