From f2fb4d5d0135ec7f1ab5ef4923909d662ecc69dd Mon Sep 17 00:00:00 2001
From: Aurel Feer <aurel.feer@gmail.com>
Date: Wed, 30 Mar 2022 16:23:39 +0200
Subject: [PATCH] start memory server

---
 include/aos/aos_rpc.h |  2 ++
 lib/aos/init.c        |  3 ++-
 lib/aos/ram_alloc.c   | 13 +++++++++++--
 lib/spawn/spawn.c     | 13 +++++++++++++
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/include/aos/aos_rpc.h b/include/aos/aos_rpc.h
index a12128d..ceacc4c 100644
--- a/include/aos/aos_rpc.h
+++ b/include/aos/aos_rpc.h
@@ -20,6 +20,8 @@
 // define some message types
 #define RPC_MTYPE_CHILD_ENDPOINT    1UL
 #define RPC_MTYPE_CHILD_ENDPOINT_OK 2UL
+#define RPC_MTYPE_GET_RAM_CAP       3UL
+#define RPC_MTYPE_GET_RAM_CAP_OK    4UL
 
 
 /* An RPC binding, which may be transported over LMP or UMP. */
diff --git a/lib/aos/init.c b/lib/aos/init.c
index ac0e409..2e72f9a 100644
--- a/lib/aos/init.c
+++ b/lib/aos/init.c
@@ -96,6 +96,7 @@ static int event_init_dispatch_thread(void *arg)
 }
 
 // TODO rueegges: putting it here for now. Not sure how to do rcp abstraction yet
+// receive messages sent by the init
 static void handle_init_recv(void *arg)
 {
     errval_t err;
@@ -129,7 +130,7 @@ static void handle_init_recv(void *arg)
 
     err = lmp_endpoint_register(init_chan->endpoint, get_default_waitset(), MKCLOSURE(handle_init_recv, init_chan));
     if (err_is_fail(err)) {
-        USER_PANIC_ERR(err, "Could not reregister after failed init_chan cap receive");
+        USER_PANIC_ERR(err, "[handle_init_recv]: Could not register endpoint after receiving message");
     }
 }
 
diff --git a/lib/aos/ram_alloc.c b/lib/aos/ram_alloc.c
index 1df7d64..a7f92d9 100644
--- a/lib/aos/ram_alloc.c
+++ b/lib/aos/ram_alloc.c
@@ -17,10 +17,19 @@
 #include <aos/core_state.h>
 
 /* remote (indirect through a channel) version of ram_alloc, for most domains */
+// call to the memory server to give us some ram
 static errval_t ram_alloc_remote(struct capref *ret, size_t size, size_t alignment)
 {
-    //TODO(M3): Implement me!
-    return LIB_ERR_NOT_IMPLEMENTED;
+    errval_t err;
+    // afeer: hää?
+    slot_alloc(ret);
+
+    // afeer, script page 133: get ram using rpc
+    struct aos_rpc *memchan = aos_rpc_get_memory_channel();
+    err = aos_rpc_get_ram_cap(memchan, size, alignment, ret, NULL);
+    if (err_is_fail(err)) return LIB_ERR_RAM_ALLOC;
+
+    return SYS_ERR_OK;
 }
 
 
diff --git a/lib/spawn/spawn.c b/lib/spawn/spawn.c
index 3914133..9a187be 100644
--- a/lib/spawn/spawn.c
+++ b/lib/spawn/spawn.c
@@ -47,6 +47,7 @@ static void armv8_set_registers(void *arch_load_info,
     disabled_area->regs[REG_OFFSET(PIC_REGISTER)] = got_base;
 }
 
+// receive messages sent by the child
 static void handle_child_recv(void *arg) {
     errval_t err;
     struct lmp_chan *init_chan = (struct lmp_chan *)arg;
@@ -76,6 +77,18 @@ static void handle_child_recv(void *arg) {
                 USER_PANIC_ERR(err, "Failed to send RPC_MTYPE_CHILD_ENDPOINT_OK");
             }
             break;
+        case RPC_MTYPE_GET_RAM_CAP:
+            debug_printf("[handle_init_recv]: RPC_MTYPE_GET_RAM_CAP\n");
+
+            size_t requested_size = msg.words[1];
+            struct capref new_ram_cap;
+            frame_alloc(&new_ram_cap, requested_size, NULL);
+
+            err = lmp_chan_send1(init_chan, LMP_FLAG_YIELD | LMP_FLAG_SYNC, NULL_CAP, RPC_MTYPE_GET_RAM_CAP_OK);
+            if (err_is_fail(err)) {
+                USER_PANIC_ERR(err, "Failed to send RPC_MTYPE_GET_RAM_CAP_OK");
+            }
+            break;
         default:
             USER_PANIC("Unknown rpc message type.");
             break;