Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>

We should not use typedefs in U-Boot. They cannot be used as forward
declarations which means that header files must include the full header to
access them.

Drop the typedef and rename the struct to remove the _s suffix which is
now not useful.

This requires quite a few header-file additions.

Signed-off-by: Simon Glass <sjg@chromium.org>

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>

We should not be using typedefs and these make it harder to use
forward declarations (to reduce header file inclusions). Drop the typedef.

Signed-off-by: Simon Glass <sjg@chromium.org>

These have been reported by Simon in [1] and fixed in [2].
However, since [1] has already been pushed to u-boot/master, the
improvements incorporated in [2] are now extracted and resubmitted.

The changes are in the area of coding style and best practices:
* s/field/fieldp/, s/size/sizep/, to convey that the variables return
  an output to the caller
* s/err_1/err_read_fail/, s/err_2/err_too_small/, to be more descriptive
* Made sure 'static int do_bcb_load' appears on the same line
* Placed a `/*` on top of multi-line comment

[1] https://patchwork.ozlabs.org/patch/1104244/#2200259
[2] https://patchwork.ozlabs.org/cover/1128661/
   ("[v4,0/4] Add 'bcb' command to read/modify/write Android BCB")

Fixes: db7b7a05b267 ("cmd: Add 'bcb' command to read/modify/write BCB fields")
Reported-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>

Quote from https://patchwork.ozlabs.org/patch/1104244/#2210814:

 ----------8<-----------
strncmp() is chosen for the sake of paranoid/defensive programming.
Indeed, strncmp() is not really needed when comparing a variable
with a string literal. We expect strcmp() to behave safely even if the
string variable is not NUL-terminated.

In the same scenario, Linux v5.2-rc7 uses both strcmp() and strncmp(),
but the frequency of strcmp() is higher:

$ git --version
git version 2.22.0
$ (Linux 5.2-rc7) git grep -En 'strncmp\([^"]*"[[:alnum:]]+"' | wc -l
1066
$ (Linux 5.2-rc7) git grep -En 'strcmp\([^"]*"[[:alnum:]]+"' | wc -l
1968

A quick "strcmp vs strncmp" object size test shows that strcmp()
generates smaller memory footprint (gcc-8, x86_64):

$ (U-Boot) size cmd/bcb-strncmp.o cmd/bcb-strcmp.o
   text	   data	    bss	    dec	    hex	filename
   3373	    400	   2048	   5821	   16bd	cmd/bcb-strncmp.o
   3314	    400	   2048	   5762	   1682	cmd/bcb-strcmp.o

So, overall, I agree to use strcmp() whenever variables are compared
with string literals.
 ----------8<-----------

Fixes: db7b7a05b267 ("cmd: Add 'bcb' command to read/modify/write BCB fields")
Reported-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Igor Opaniuk <igor.opaniuk@gmail.com>

Fix warning V1037 reported by PVS-Studio Static Analyzer:
Two or more case-branches perform the same actions. Check lines: 49, 53

Fixes: db7b7a05b267 ("cmd: Add 'bcb' command to read/modify/write BCB fields")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Igor Opaniuk <igor.opaniuk@gmail.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>

'Bootloader Control Block' (BCB) is a well established term/acronym in
the Android namespace which refers to a location in a dedicated raw
(i.e. FS-unaware) flash (e.g. eMMC) partition, usually called "misc",
which is used as media for exchanging messages between Android userspace
(particularly recovery [1]) and an Android-capable bootloader.

On higher level, this allows implementing a subset of Android Bootloader
Requirements [2], amongst which is the Android-specific bootloader
flow [3]. Regardless how the latter is implemented in U-Boot ([3] being
the most memorable example), reading/writing/dumping the BCB fields in
the development process from inside the U-Boot is a convenient feature.
Hence, make it available to the users.

Some usage examples of the new command recorded on R-Car H3ULCB-KF
('>>>' is an overlay on top of the original console output):

=> bcb
bcb - Load/set/clear/test/dump/store Android BCB fields

Usage:
bcb load  <dev> <part>       - load  BCB from mmc <dev>:<part>
bcb set   <field> <val>      - set   BCB <field> to <val>
bcb clear [<field>]          - clear BCB <field> or all fields
bcb test  <field> <op> <val> - test  BCB <field> against <val>
bcb dump  <field>            - dump  BCB <field>
bcb store                    - store BCB back to mmc

Legend:
<dev>   - MMC device index containing the BCB partition
<part>  - MMC partition index or name containing the BCB
<field> - one of {command,status,recovery,stage,reserved}
<op>    - the binary operator used in 'bcb test':
          '=' returns true if <val> matches the string stored in <field>
          '~' returns true if <val> matches a subset of <field>'s string
<val>   - string/text provided as input to bcb {set,test}
          NOTE: any ':' character in <val> will be replaced by line feed
          during 'bcb set' and used as separator by upper layers

=> bcb dump command
Error: Please, load BCB first!
 >>> Users must specify mmc device and partition before any other call

=> bcb load 1 misc
=> bcb load 1 1
 >>> The two calls are equivalent (assuming "misc" has index 1)

=> bcb dump command
00000000: 62 6f 6f 74 6f 6e 63 65 2d 73 68 65 6c 6c 00 72    bootonce-shell.r
00000010: 79 00 72 00 00 00 00 00 00 00 00 00 00 00 00 00    y.r.............
 >>> The output is in binary/string format for convenience
 >>> The output size matches the size of inspected BCB field
 >>> (32 bytes in case of 'command')

=> bcb test command = bootonce-shell && echo true
true
=> bcb test command = bootonce-shell- && echo true
=> bcb test command = bootonce-shel && echo true
 >>> The '=' operator returns 'true' on perfect match

=> bcb test command ~ bootonce-shel && echo true
true
=> bcb test command ~ bootonce-shell && echo true
true
 >>> The '~' operator returns 'true' on substring match

=> bcb set command recovery
=> bcb dump command
00000000: 72 65 63 6f 76 65 72 79 00 73 68 65 6c 6c 00 72    recovery.shell.r
00000010: 79 00 72 00 00 00 00 00 00 00 00 00 00 00 00 00    y.r.............
 >>> The new value is NULL-terminated and stored in the BCB field

=> bcb set recovery "msg1:msg2:msg3"
=> bcb dump recovery
00000040: 6d 73 67 31 0a 6d 73 67 32 0a 6d 73 67 33 00 00    msg1.msg2.msg3..
00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
 >>> --- snip ---
 >>> Every ':' is replaced by line-feed '\n' (0xA). The latter is used
 >>> as separator between individual commands by Android userspace

=> bcb store
 >>> Flush/store the BCB structure to MMC

[1] https://android.googlesource.com/platform/bootable/recovery
[2] https://source.android.com/devices/bootloader
[3] https://patchwork.ozlabs.org/patch/746835/
    ("[U-Boot,5/6] Initial support for the Android Bootloader flow")

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>