karo: configs: Update the tx6*_defconfig files from defconfigs generated with 'make...

[karo-tx-uboot.git] / doc / README.commands

diff --git a/doc/README.commands b/doc/README.commands
index d848db01ef2cbd4a9db62339156152084b2e90cb..afd5577b0a9ce66b86c52f7cae595eb7d914e556 100644 (file)
--- a/doc/README.commands
+++ b/doc/README.commands
@@ -1,101 +1,36 @@
-#
-# The commands in this table are sorted alphabetically by the
-# command name and in descending order by the command name string
-# length. This is to prevent conflicts in command name parsing.
-# Please ensure that new commands are added according to that rule.
-# See $(TOPDIR)/common/command.c
-#
-########################
-#
-# command      length
-#
-########################
-askenv         8
-as             2
-autoscr                5
-base           2
-bdinfo         2
-bmp            3
-bootelf                7
-bootm          5
-bootp          5
-bootvx         6
-bootd          4
-break          2
-brginfo                3
-carinfo                3
-chpart         6
-cmp            3
-coninfo                5
-continue       4
-cp             2
-crc32          3
-date           3
-dcache         2
-dhcp           4
-dmainfo                3
-ds             2
-dtt            3
-echo           4
-eeprom         3
-erase          3
-fccinfo                3
-fdcboot                4
-flinfo         3
-fpga           4
-fsinfo         5
-fsload         5
-getdcr         6               # IBM 4XX DCR registers
-go             2
-help           1
-i2cinfo                4
-i2c            3
-icache         2
-icinfo         3
-ide            3
-iminfo         3
-iopinfo                3
-irqinfo                3
-kgdb           4
-loadb          5
-loads          5
-loop           4
-ls             2
-mccinfo                3
-md             2
-memcinfo       4
-mii            3
-mm             2
-mtest          5
-muxinfo                3
-mw             2
-next           4
-nm             2
-pciinfo                3
-pinit          4
-printenv       8
-protect                4
-rarpboot       4
-rdump          5
-reginfo                3
-reset          5
-run            3
-saveenv                4
-sccinfo                3
-scsiboot       5
-scsi           4
-siiinfo                3
-sitinfo                3
-siuinfo                3
-setdcr         6               # IBM 4XX DCR registers
-setenv         6
-smcinfo                3
-spiinfo                3
-sspi           4
-stack          5
-step           4
-tftpboot       4
-usbboot                5
-usb            4
-version                4
-?              1
+
+Commands are added to U-Boot by creating a new command structure.
+This is done by first including command.h, then using the U_BOOT_CMD() macro
+to fill in a cmd_tbl_t struct.
+
+U_BOOT_CMD(name,maxargs,repeatable,command,"usage","help")
+
+name:   is the name of the commad. THIS IS NOT a string.
+maxargs: the maximum number of arguments this function takes
+repeatable: either 0 or 1 to indicate if autorepeat is allowed
+command: Function pointer (*cmd)(struct cmd_tbl_s *, int, int, char *[]);
+usage:  Short description. This is a string
+help:   Long description. This is a string
+
+
+**** Behind the scene ******
+
+The structure created is named with a special prefix and placed by
+the linker in a special section using the linker lists mechanism
+(see include/linker_lists.h)
+
+This makes it possible for the final link to extract all commands
+compiled into any object code and construct a static array so the
+command array can be iterated over using the linker lists macros.
+
+The linker lists feature ensures that the linker does not discard
+these symbols when linking full U-Boot even though they are not
+referenced in the source code as such.
+
+If a new board is defined do not forget to define the command section
+by writing in u-boot.lds ($(srctree)/board/boardname/u-boot.lds) these
+3 lines:
+
+       .u_boot_list : {
+               KEEP(*(SORT(.u_boot_list*)));
+       }