gdb_server: support File-I/O Remote Protocol Extension

The File I/O remote protocol extension allows the target to use the
host's file system and console I/O to perform various system calls.

To use the function, targets need to prepare two callback functions:
* get_gdb_finish_info: to get file I/O parameters from target
* gdb_fileio_end: pass file I/O response to target

As target is halted, gdb_server will try to get file-I/O information
from target through target_get_gdb_fileio_info(). If the callback function
returns ERROR_OK, gdb_server will initiate a file-I/O request to gdb.
After gdb finishes system call, gdb will pass response of the system call
to target through target_gdb_fileio_end() and continue to run(continue or step).

To implement the function, I add a new data structure in struct target,
called struct gdb_fileio_info, to record file I/O name and parameters.

Details refer to GDB manual "File-I/O Remote Protocol Extension"

Change-Id: I7f4d45e7c9e967b6d898dc79ba01d86bc46315d3
Signed-off-by: Hsiangkai Wang <hsiangkai@gmail.com>
Reviewed-on: http://openocd.zylin.com/1102
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/target/nds32.h b/src/target/nds32.h
index b7e787c..8acd915 100644
--- a/src/target/nds32.h
+++ b/src/target/nds32.h
@@ -284,6 +284,18 @@ struct nds32 {
 	/** Flag reporting whether virtual hosting is active. */
 	bool virtual_hosting;
 
+	/** Flag reporting whether continue/step hits syscall or not */
+	bool hit_syscall;
+
+	/** Value to be returned by virtual hosting SYS_ERRNO request. */
+	int virtual_hosting_errno;
+
+	/** Flag reporting whether syscall is aborted */
+	bool virtual_hosting_ctrl_c;
+
+	/** Record syscall ID for other operations to do special processing for target */
+	int active_syscall_id;
+
 	/** Flag reporting whether global stop is active. */
 	bool global_stop;
 
@@ -404,6 +416,10 @@ extern int nds32_resume(struct target *target, int current,
 		uint32_t address, int handle_breakpoints, int debug_execution);
 extern int nds32_assert_reset(struct target *target);
 extern int nds32_init(struct nds32 *nds32);
+extern int nds32_get_gdb_fileio_info(struct target *target, struct gdb_fileio_info *fileio_info);
+extern int nds32_gdb_fileio_write_memory(struct nds32 *nds32, uint32_t address,
+		uint32_t size, const uint8_t *buffer);
+extern int nds32_gdb_fileio_end(struct target *target, int retcode, int fileio_errno, bool ctrl_c);
 extern int nds32_reset_halt(struct nds32 *nds32);
 extern int nds32_login(struct nds32 *nds32);