Add command to erase all flash memory regions

Changes in v4:

- Replaced phex call with hex_string.

Changes in v3:

- Addressed comments by Pedro.
- Output of memory region size now in hex format.
- Misc formatting fixups.
- Addressed Simon's comments on formatting.
- Adjusted command text in the manual entry.
- Fixed up ChangeLog.
- Renamed flash_erase_all_command to flash_erase_command.

Changes in v2:

- Added NEWS entry.
- Fixed long lines.
- Address printing with paddress.

Years ago we contributed flash programming patches upstream.  The following
patch is a leftover one that complements that functionality by adding a new
command to erase all reported flash memory blocks.

The command is most useful when we're dealing with flash-enabled targets
(mostly bare-metal) and we need to reset the board for some reason.

The wiping out of flash memory regions should help the target come up with a
known clean state from which the user can load a new image and resume
debugging. It is convenient enough to do this from the debugger, and there is
also an MI command to expose this functionality to the IDE's.

gdb/doc/ChangeLog:

2017-01-20  Mike Wrighton  <mike_wrighton@codesourcery.com>
	    Luis Machado  <lgustavo@codesourcery.com>

	* gdb.texinfo (-target-flash-erase): New MI command description.
	(flash-erase): New CLI command description.

gdb/ChangeLog:

2017-01-20  Mike Wrighton  <mike_wrighton@codesourcery.com>
	    Luis Machado  <lgustavo@codesourcery.com>

	* NEWS (New commands): Mention flash-erase.
	(New MI commands): Mention target-flash-erase.
	* mi/mi-cmds.c (mi_cmd_target_flash_erase): Add target-flash-erase MI
	command.
	* mi/mi-cmds.h (mi_cmd_target_flash_erase): New declaration.
	* mi/mi-main.c (mi_cmd_target_flash_erase): New function.
	* target.c (flash_erase_command): New function.
	(initialize_targets): Add new flash-erase command.
	* target.h (flash_erase_command): New declaration.

1 files changed, 32 insertions, 0 deletions

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 2b6b654..dcca91b 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -19622,6 +19622,16 @@ load programs into flash memory.
 @code{load} does not repeat if you press @key{RET} again after using it.
 @end table
 
+@table @code
+
+@kindex flash-erase
+@item flash-erase
+@anchor{flash-erase}
+
+Erases all known flash memory regions on the target.
+
+@end table
+
 @node Byte Order
 @section Choosing Target Byte Order
 
@@ -31859,6 +31869,28 @@ No equivalent.
 @subsubheading Example
 N.A.
 
+@subheading The @code{-target-flash-erase} Command
+@findex -target-flash-erase
+
+@subsubheading Synopsis
+
+@smallexample
+ -target-flash-erase
+@end smallexample
+
+Erases all known flash memory regions on the target.
+
+The corresponding @value{GDBN} command is @samp{flash-erase}.
+
+The output is a list of flash regions that have been erased, with starting
+addresses and memory region sizes.
+
+@smallexample
+(gdb)
+-target-flash-erase
+^done,erased-regions=@{address="0x0",size="0x40000"@}
+(gdb)
+@end smallexample
 
 @subheading The @code{-target-select} Command
 @findex -target-select