libtock: do not include syscalls

Apps should specify they use syscalls directly.

Need to duplicate the exists() function to make this work.

Author: bradjc

doc/guide.md

@@ -170,13 +170,13 @@ There must be a function to check for syscall driver existence.
 Signature:
 
 ```
-bool libtock_[name]_exists(void);
+bool libtock_[name]_driver_exists(void);
 ```
 
 Example:
 
 ```c
-bool libtock_[name]_exists(void) {
+bool libtock_[name]_driver_exists(void) {
   return driver_exists(DRIVER_NUM_[NAME]);
 }
 ```
@@ -202,7 +202,6 @@ The `[name].h` header file must look like:
 #pragma once
 
 #include "../tock.h"
-#include "syscalls/[name]_syscalls.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -215,7 +214,8 @@ extern "C" {
 #endif
 ```
 
-The `[name].h` header file must include the syscalls header.
+The `[name].h` header file must NOT include the syscalls header. Applications
+wanting to use the syscalls directly must include the syscalls header.
 
 ### Defining a Callback for Asynchronous Operations
 
@@ -236,6 +236,24 @@ they should have the last argument be a callback function pointer.
 returncode_t libtock_[name]_[desc](<arguments>, libtock_[name]_callback_[desc] cb);
 ```
 
+#### Exists
+
+There must be a function to check for syscall driver existence.
+
+Signature:
+
+```
+bool libtock_[name]_exists(void);
+```
+
+Example:
+
+```c
+bool libtock_[name]_exists(void) {
+  return libtock_[name]_driver_exists();
+}
+```
+
 ### Example:
 
 
@@ -309,7 +327,6 @@ file is used in a C++ app.
 #pragma once
 
 #include <libtock/tock.h>
-#include <libtock/[category]/syscalls/[name]_syscalls.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -379,7 +396,6 @@ The libtock-sync `[name].h` header file must look like:
 ```c
 #pragma once
 
-#include "syscalls/temperature_syscalls.h"
 #include <libtock/tock.h>
 
 #ifdef __cplusplus

examples/tests/aes/main.c

@@ -3,6 +3,7 @@
 #include <string.h>
 
 #include <libtock/crypto/aes.h>
+#include <libtock/crypto/syscalls/aes_syscalls.h>
 
 #define KEY_LEN  16
 #define IV_LEN  16

libtock/crypto/aes.c

@@ -1,4 +1,9 @@
 #include "aes.h"
+#include "syscalls/aes_syscalls.h"
+
+bool libtock_aes_exists(void) {
+  return libtock_aes_driver_exists();
+}
 
 returncode_t libtock_aes_set_algorithm(libtock_aes_algorithm_t operation, bool encrypting) {
   return libtock_aes_command_set_algorithm((uint8_t) operation, encrypting);

libtock/crypto/aes.h

@@ -1,7 +1,6 @@
 #pragma once
 
 #include "../tock.h"
-#include "syscalls/aes_syscalls.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -14,6 +13,9 @@ typedef enum {
   LIBTOCK_AES128CCM = 3
 } libtock_aes_algorithm_t;
 
+// Check if the AES driver exists on this system.
+bool libtock_aes_exists(void);
+
 // Set the AES algorithm
 // operation:
 //    * 0 -> AES128Ctr

libtock/crypto/hmac.c

@@ -1,4 +1,5 @@
 #include "hmac.h"
+#include "syscalls/hmac_syscalls.h"
 
 static void hmac_upcall(int ret,
                         __attribute__ ((unused)) int unused1,
@@ -7,6 +8,9 @@ static void hmac_upcall(int ret,
   cb(tock_status_to_returncode(ret));
 }
 
+bool libtock_hmac_exists(void) {
+  return libtock_hmac_driver_exists();
+}
 
 returncode_t libtock_hmac_simple(libtock_hmac_algorithm_t hmac_type,
                                  uint8_t* key_buffer, uint32_t key_length,

libtock/crypto/hmac.h

@@ -2,7 +2,6 @@
 
 #include "../tock.h"
 #include "hmac_types.h"
-#include "syscalls/hmac_syscalls.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -13,6 +12,7 @@ extern "C" {
 // - `arg1` (`returncode_t`): Status from computing the HMAC.
 typedef void (*libtock_hmac_callback_hmac)(returncode_t);
 
+bool libtock_hmac_exists(void);
 
 // Compute an HMAC using `keyb_buffer` over `input_buffer` and store the result
 // in `hash_buffer`.

libtock/crypto/sha.c

@@ -1,4 +1,5 @@
 #include "sha.h"
+#include "syscalls/sha_syscalls.h"
 
 static void sha_upcall(int status,
                        __attribute__ ((unused)) int unused1,
@@ -7,6 +8,10 @@ static void sha_upcall(int status,
   cb(tock_status_to_returncode(status));
 }
 
+bool libtock_sha_exists(void) {
+  return libtock_sha_driver_exists();
+}
+
 returncode_t libtock_sha_simple_hash(libtock_sha_algorithm_t hash_type,
                                      uint8_t* input_buffer, uint32_t input_length,
                                      uint8_t* hash_buffer, uint32_t hash_length,

libtock/crypto/sha.h

@@ -1,7 +1,6 @@
 #pragma once
 
 #include "../tock.h"
-#include "syscalls/sha_syscalls.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -19,6 +18,7 @@ typedef enum {
 } libtock_sha_algorithm_t;
 
 
+bool libtock_sha_exists(void);
 
 // Compute a SHA hash over `input_buffer` and store the hash in `hash_buffer`.
 //

libtock/crypto/syscalls/aes_syscalls.c

@@ -17,7 +17,7 @@
 #define TOCK_AES_CCM_MIC_LEN     7
 #define TOCK_AES_CCM_CONF        8
 
-bool libtock_aes_exists(void) {
+bool libtock_aes_driver_exists(void) {
   return driver_exists(DRIVER_NUM_AES);
 }
 

libtock/crypto/syscalls/aes_syscalls.h

@@ -8,7 +8,7 @@ extern "C" {
 
 #define DRIVER_NUM_AES 0x40006
 
-bool libtock_aes_exists(void);
+bool libtock_aes_driver_exists(void);
 
 returncode_t libtock_aes_set_upcall(subscribe_upcall callback, void* opaque);