Commit c9494866 authored by Ben Gardiner's avatar Ben Gardiner Committed by Scott Wood

cmd_nand: add nand write.trimffs command

Add another nand write. variant, trimffs. This command will request of
nand_write_skip_bad() that all trailing all-0xff pages will be
dropped from eraseblocks when they are written to flash as-per the
reccommended behaviour of the UBI FAQ [1].

The function that implements this timming is the drop_ffs() function
by Artem Bityutskiy, ported from the mtd-utils tree.

[1] default avatarBen Gardiner <>
CC: Artem Bityutskiy <>
CC: Detlev Zundel <>
Acked-by: default avatarScott Wood <>
Signed-off-by: default avatarScott Wood <>
parent 169d54d8
......@@ -575,6 +575,16 @@ int do_nand(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
ret = nand_write_skip_bad(nand, off, &rwsize,
(u_char *)addr, 0);
} else if (!strcmp(s, ".trimffs")) {
if (read) {
printf("Unknown nand command suffix '%s'\n", s);
return 1;
ret = nand_write_skip_bad(nand, off, &rwsize,
(u_char *)addr,
} else if (!strcmp(s, ".yaffs")) {
if (read) {
......@@ -689,6 +699,12 @@ U_BOOT_CMD(
"nand write - addr off|partition size\n"
" read/write 'size' bytes starting at offset 'off'\n"
" to/from memory address 'addr', skipping bad blocks.\n"
"nand write.trimffs - addr off|partition size\n"
" write 'size' bytes starting at offset 'off' from memory address\n"
" 'addr', skipping bad blocks and dropping any pages at the end\n"
" of eraseblocks that contain only 0xFF\n"
"nand write.yaffs - addr off|partition size\n"
" write 'size' bytes starting at offset 'off' with yaffs format\n"
......@@ -78,6 +78,16 @@ Commands:
should work well, but loading an image copied from another flash is
going to be trouble if there are any bad blocks.
nand write.trimffs addr ofs|partition size
Enabled by the CONFIG_CMD_NAND_TRIMFFS macro. This command will write to
the NAND flash in a manner identical to the 'nand write' command
described above -- with the additional check that all pages at the end
of eraseblocks which contain only 0xff data will not be written to the
NAND flash. This behaviour is required when flashing UBI images
containing UBIFS volumes as per the UBI FAQ[1].
nand write.oob addr ofs|partition size
Write `size' bytes from `addr' to the out-of-band data area
corresponding to `ofs' in NAND flash. This is limited to the 16 bytes
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