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author | Heinrich Schuchardt <heinrich.schuchardt@canonical.com> | 2022-09-10 10:16:37 +0300 |
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committer | Heinrich Schuchardt <heinrich.schuchardt@canonical.com> | 2022-09-30 03:03:23 +0300 |
commit | 0e21943b94a86f8f9d7b95eecd18d18742296b3c (patch) | |
tree | 224d69681cffc567e960c6b288d92288381d936d /doc/usage | |
parent | 435596d57f8beedf36b5dc858fe7ba9d6c03334b (diff) | |
download | u-boot-0e21943b94a86f8f9d7b95eecd18d18742296b3c.tar.xz |
doc: improve description of autostart
Complete the list of commands influenced by the autostart environment
variable.
Make it clearer what values qualifies at 'yes'.
Eventually the list of environment variables is to be alphabetically
sorted. Move autostart up.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'doc/usage')
-rw-r--r-- | doc/usage/environment.rst | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/doc/usage/environment.rst b/doc/usage/environment.rst index 561076bac9..7906ace2af 100644 --- a/doc/usage/environment.rst +++ b/doc/usage/environment.rst @@ -106,6 +106,27 @@ many cases the value in the default environment comes from a CONFIG option - see This is most-likely not complete: +autostart + If set to "yes" (actually any string starting with 1, y, Y, t, or T) an + image loaded with one of the commands listed below will be automatically + started by internally invoking the bootm command. + + * bootelf - Boot from an ELF image in memory + * bootp - boot image via network using BOOTP/TFTP protocol + * dhcp - boot image via network using DHCP/TFTP protocol + * diskboot - boot from ide device + * nboot - boot from NAND device + * nfs - boot image via network using NFS protocol + * rarpboot - boot image via network using RARP/TFTP protocol + * scsiboot - boot from SCSI device + * tftpboot - boot image via network using TFTP protocol + * usbboot - boot from USB device + + If the environment variable autostart is not set to a value starting with + 1, y, Y, t, or T, an image passed to the "bootm" command will be copied to + the load address (and eventually uncompressed), but NOT be started. + This can be used to load and uncompress arbitrary data. + baudrate Used to set the baudrate of the UART - it defaults to CONFIG_BAUDRATE (which defaults to 115200). @@ -174,19 +195,6 @@ autoload configuration from the BOOTP server, but not try to load any image. -autostart - if set to "yes", an image loaded using the "bootp", "dhcp", - "rarpboot", "tftpboot" or "diskboot" commands will - be automatically started (by internally calling - "bootm") - - If unset, or set to "1"/"yes"/"true" (case insensitive, just the first - character is enough), a standalone image - passed to the "bootm" command will be copied to the load address - (and eventually uncompressed), but NOT be started. - This can be used to load and uncompress arbitrary - data. - fdt_high if set this restricts the maximum address that the flattened device tree will be copied into upon boot. |