Bugfixes for serial read rpc. Using kernel sys_getchar for dummy terminal read. Added silly shell to hello.c

include/aos/aos_rpc.h

@@ -145,4 +145,34 @@ struct aos_rpc *aos_rpc_get_process_channel(void);
  */
 struct aos_rpc *aos_rpc_get_serial_channel(void);
 
+// MARKER SHELL: remove these temprorary functions
+static inline size_t dummy_terminal_write(const char *buf, size_t len)
+{
+    errval_t err;
+    
+    if (len > 0) {
+        err = sys_print(buf, len);
+        if (err_is_fail(err)) {
+            return 0;
+        }
+    }
+
+    return len;
+}
+static inline size_t dummy_terminal_read(char *buf, size_t len)
+{
+    errval_t err;
+
+    // we need this for now cause sys_getchar is blocking and not even allowing other processes to run
+    if(len > 1) len = 1;
+
+    for(size_t i = 0; i < len; ++i) {
+        err = sys_getchar(&buf[i]);
+        if (err_is_fail(err)) {
+            return i;
+        }
+    }
+    return len;
+}
+
 #endif // _LIB_BARRELFISH_AOS_MESSAGES_H

lib/aos/aos_rpc.c

@@ -146,8 +146,10 @@ aos_rpc_serial_write(struct aos_rpc *rpc, const char *buf, size_t buf_len) {
             NULL, NULL, &written_bytes, NULL
         );
         if (err_is_fail(err)) {
+            DEBUG_ERR(err, "Failed to write the full buffer");
             return total_bytes;
         }
+        assert(written_bytes <= chunk_len);
 
         total_bytes += written_bytes;
 
@@ -176,13 +178,15 @@ aos_rpc_serial_read(struct aos_rpc *rpc, char *buf, size_t buf_len) {
 
         size_t read_bytes;
         err = do_aos_rpc(
-            rpc, RPC_MTYPE_SERIAL_WRITE,
+            rpc, RPC_MTYPE_SERIAL_READ,
             NULL_CAP, 0, chunk_len, 0,
-            NULL, NULL, &read_bytes, NULL
+            NULL, &read_bytes, NULL, NULL
         );
         if (err_is_fail(err)) {
+            DEBUG_ERR(err, "Failed to read the full buffer");
             return total_bytes;
         }
+        assert(read_bytes <= chunk_len);
 
         memcpy(buf, rpc->shared_mem, read_bytes);
         total_bytes += read_bytes;

lib/aos/init.c

@@ -64,24 +64,24 @@ static void libc_assert(const char *expression, const char *file,
     sys_print(buf, len < sizeof(buf) ? len : sizeof(buf));
 }
 
-__attribute__((__used__))
-static size_t syscall_terminal_write(const char *buf, size_t len)
-{
-    if(len) {
-        errval_t err = sys_print(buf, len);
-        if (err_is_fail(err)) {
-            return 0;
-        }
-    }
-    return len;
-}
+// __attribute__((__used__))
+// static size_t syscall_terminal_write(const char *buf, size_t len)
+// {
+//     if(len) {
+//         errval_t err = sys_print(buf, len);
+//         if (err_is_fail(err)) {
+//             return 0;
+//         }
+//     }
+//     return len;
+// }
 
-__attribute__((__used__))
-static size_t dummy_terminal_read(char *buf, size_t len)
-{
-    debug_printf("Terminal read NYI!\n");
-    return 0;
-}
+// __attribute__((__used__))
+// static size_t dummy_terminal_read(char *buf, size_t len)
+// {
+//     debug_printf("Terminal read NYI!\n");
+//     return 0;
+// }
 
 static void handle_init_recv(void *arg)
 {
@@ -101,7 +101,6 @@ static void handle_init_recv(void *arg)
     }
 }
 
-// TODO rueegges: allow partial write
 static size_t aos_terminal_write(const char *buf, size_t len)
 {
     if(len == 0) return 0;
@@ -115,7 +114,6 @@ static size_t aos_terminal_write(const char *buf, size_t len)
     return aos_rpc_serial_write(rpc, buf, len);
 }
 
-// TODO rueegges: make more efficient?
 static size_t aos_terminal_read(char *buf, size_t len)
 {
     if(len == 0) return 0;
@@ -136,10 +134,10 @@ void barrelfish_libc_glue_init(void)
     // what we need for that
     // TODO: change these to use the user-space serial driver if possible
     // TODO: set these functions
-    // MARKER SHELL: replace functions for init domain or UART driver with non-remote calls
+    // MARKER SHELL: init should also print through the UART driver
     if(init_domain) {
         _libc_terminal_read_func = dummy_terminal_read;
-        _libc_terminal_write_func = syscall_terminal_write;
+        _libc_terminal_write_func = dummy_terminal_write;
     } else {
         _libc_terminal_read_func = aos_terminal_read;
         _libc_terminal_write_func = aos_terminal_write;

lib/spawn/rpc_server.c

@@ -146,7 +146,7 @@ static errval_t handle_rpc_serial_getchar(
     // MARKER SHELL: Replace with UART call
     *ret0 = getchar();
 
-    return LIB_ERR_NOT_IMPLEMENTED;
+    return SYS_ERR_OK;
 }
 
 static errval_t handle_rpc_serial_putchar(
@@ -170,12 +170,8 @@ static errval_t handle_rpc_serial_write(
     struct capref *ret_cap, size_t *ret_size, uintptr_t *ret0, uintptr_t *ret1
 ) {
     // MARKER SHELL: Replace with UART call
-    for (size_t i = 0; i < arg_size; ++i){
-        putchar(((char *)rpc->shared_mem)[i]);
-    }
-
     // return the number of characters written. Important for UART for early return when the buffer is full
-    *ret0 = arg_size;
+    *ret0 = dummy_terminal_write((char *)rpc->shared_mem, arg_size);
 
     return SYS_ERR_OK;
 }
@@ -186,12 +182,8 @@ static errval_t handle_rpc_serial_read(
     struct capref *ret_cap, size_t *ret_size, uintptr_t *ret0, uintptr_t *ret1
 ) {
     // MARKER SHELL: Replace with UART call
-    for (size_t i = 0; i < arg_size; ++i){
-        ((char *)rpc->shared_mem)[i] = getchar();
-    }
-
     // return the number of characters read. Important for UART for early return when the buffer is empty
-    *ret0 = arg_size;
+    *ret_size = dummy_terminal_read((char *)rpc->shared_mem, arg0);
 
     return SYS_ERR_OK;
 }

usr/hello/hello.c

@@ -24,6 +24,8 @@
 #define HELLO_CATCH_COMMAND "catch"
 #define HELLO_SPAWN_COMMAND "spawn"
 
+#define HELLO_CMDLINE_READ_LEN 100
+
 int main(int argc, char *argv[])
 {
     errval_t err;
@@ -43,10 +45,39 @@ int main(int argc, char *argv[])
 
     // try to spawn a child using rpc
     if (argc > 1 && !strncmp(argv[1], HELLO_SPAWN_COMMAND, sizeof(HELLO_SPAWN_COMMAND))) {
+        debug_printf("Waiting for 1s before showing shell because kernel getchar blocks everything!\n");
+        barrelfish_usleep(1000000);
+
+        debug_printf("# ");
+        // try to read cmdline from the terminal (a very very primitive shell)
+        char cmdline[HELLO_CMDLINE_READ_LEN+1];
+        for(int i = 0; i < HELLO_CMDLINE_READ_LEN; ++i) {
+            char c = getchar();
+            if(c == '\r') {
+                printf("\n");
+                cmdline[i] = '\0';
+                break;
+            }
+            if(c == 0x7f) {
+                if (i > 0) {
+                    printf("\b \b"); fflush(stdout);
+                }
+                --i;
+                if(i >= 0) --i;
+                continue;
+            }
+
+            cmdline[i] = c;
+            printf("%c", c); fflush(stdout);
+        }
+        cmdline[HELLO_CMDLINE_READ_LEN] = '\0';
+
+        printf("Got command line: %s\n", cmdline);
+
         // start process
         domainid_t pid;
         rpc = aos_rpc_get_process_channel();
-        err = aos_rpc_process_spawn(rpc, "hello Aurel Jan Sandro", 0, &pid);
+        err = aos_rpc_process_spawn(rpc, cmdline, 0, &pid);
         if (err_is_fail(err)) USER_PANIC_ERR(err, "Failed to spawn process");
         printf("Started a new process!\n");