Kernel: Pass process arguments directly on the stack.

Get rid of the convoluted get_arguments and get_environment syscalls.
This patch also adds a simple /bin/env that just prints its environment.

Userland/.gitignore

@@ -34,3 +34,4 @@ pape
 ln
 df
 su
+env

Userland/Makefile

@@ -30,6 +30,7 @@ OBJS = \
        df.o \
        ln.o \
        su.o \
+       env.o \
        rm.o
 
 APPS = \
@@ -65,6 +66,7 @@ APPS = \
        ln \
        df \
        su \
+       env \
        rm
 
 ARCH_FLAGS =
@@ -184,6 +186,9 @@ df: df.o
 su: su.o
 	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
 
+env: env.o
+	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
+
 .cpp.o:
 	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
 

Userland/env.cpp

@@ -0,0 +1,9 @@
+#include <unistd.h>
+#include <stdio.h>
+
+int main(int, char**)
+{
+    for (size_t i = 0; environ[i]; ++i)
+        printf("%s\n", environ[i]);
+    return 0;
+}