feat(utk): Add CLI flag -erase-polarity

[xaionaro]

ITS: #356

Before

xaionaro@void:~/go/src/github.com/linuxboot/fiano$ dd if=/dev/zero of=/tmp/image bs=1K count=64
64+0 records in
64+0 records out
65536 bytes (66 kB, 64 KiB) copied, 0.001032 s, 63.5 MB/s
xaionaro@void:~/go/src/github.com/linuxboot/fiano$ go run ./cmds/utk/ /tmp/image create-fv $((32 * 1024)) $((32 * 1024-16)) "61C0F511-A691-4F54-974F-B9A42172CE53" save /tmp/new_image
2022/01/17 21:12:43 [fiano][FATAL] building ExtHeader erase polarity not 0x00 or 0xFF, got 0xf0
exit status 1

After

xaionaro@void:~/go/src/github.com/linuxboot/fiano$ dd if=/dev/zero of=/tmp/image bs=1K count=64
64+0 records in
64+0 records out
65536 bytes (66 kB, 64 KiB) copied, 0.00095363 s, 68.7 MB/s
xaionaro@void:~/go/src/github.com/linuxboot/fiano$ go run ./cmds/utk/ -erase-polarity=0xFF /tmp/image create-fv $((32 * 1024)) $((32 * 1024-16)) "61C0F511-A691-4F54-974F-B9A42172CE53" save /tmp/new_image
xaionaro@void:~/go/src/github.com/linuxboot/fiano$ hexdump -C /tmp/new_image
00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00008010  78 e5 8c 8c 3d 8a 1c 4f  99 35 89 61 85 c3 2d d3  |x...=..O.5.a..-.|
00008020  f0 7f 00 00 00 00 00 00  5f 46 56 48 ff fe 04 00  |........_FVH....|
00008030  48 00 78 66 60 00 00 02  07 00 00 00 00 10 00 00  |H.xf`...........|
00008040  00 00 00 00 00 00 00 00  ff ff ff ff ff ff ff ff  |................|
00008050  ff ff ff ff ff ff ff ff  f4 aa f0 00 2c 00 00 f8  |............,...|
00008060  11 f5 c0 61 91 a6 54 4f  97 4f b9 a4 21 72 ce 53  |...a..TO.O..!r.S|
00008070  14 00 00 00 ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00008080  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
*
0000fff0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00010000

[codecov-commenter]

Codecov Report

Merging #358 (0a8e8d1) into master (3c38bba) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #358   +/-   ##
=======================================
  Coverage   41.69%   41.69%           
=======================================
  Files         110      110           
  Lines        7642     7642           
=======================================
  Hits         3186     3186           
  Misses       3877     3877           
  Partials      579      579           

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[GanShun]

You don't need to do this. If you do strconv.ParseUint with a base of 0, it will detect the base automatically and include support for stuff like Octal (not that I'm sure anyone should attempt to supply it in Octal :P)

[xaionaro]

Wow. Didn't know that. Thanks, will fix!

[xaionaro]

Fixed.

[GanShun]

Is there value in ensuring the erase polarity is either 0 or 0xFF? with this we could supply 0xDE if we wanted to. I'm ok either way

[xaionaro]

If the polarity is invalid, it will panic here:
https://github.com/linuxboot/fiano/pull/358/files#diff-239a5539d7bbec3894ab256b4b20075436aa19b06b5f49995786e36163bdd837R109-R111

[GanShun]

Ah ok!