diff --git a/README.md b/README.md
index 7e5f4c48a..06d0f57fd 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,8 @@ Bugs to fix:
 - Fix not world switching during filesystem accesses (very unstable)
 - Fix the console not garbage collecting its lines (enable and test the feature)
 - Fix not resetting the shell when importing a file from command-line
+- Fix current working directory not changing during a module import (for
+  relative imports)
 
 Python features:
 - Compare features with existing implementations and other brands
diff --git a/ports/sh/debug.c b/ports/sh/debug.c
index 530034cdd..9c2f7cea0 100644
--- a/ports/sh/debug.c
+++ b/ports/sh/debug.c
@@ -3,8 +3,23 @@
 #include <gint/usb-ff-bulk.h>
 #include <gint/kmalloc.h>
 #include <gint/display.h>
+#include <gint/keyboard.h>
 #include <gint/cpu.h>
 #include <stdio.h>
+#include <stdlib.h>
+
+void pe_debug_panic(char const *msg)
+{
+    int dy = dfont_default()->line_height + 2;
+
+    dclear(C_BLACK);
+    dtext(1, 1, C_WHITE, "PythonExtra panic!");
+    dtext(1, 1+dy, C_WHITE, msg);
+    dupdate();
+
+    getkey();
+    exit(1);
+}
 
 #if PE_DEBUG
 
diff --git a/ports/sh/debug.h b/ports/sh/debug.h
index 5e2dedf9d..4f31bee69 100644
--- a/ports/sh/debug.h
+++ b/ports/sh/debug.h
@@ -7,7 +7,7 @@
 //
 // Most of the debugging occurs via USB. This module also includes screenshots
 // and other developer-only utilities. The interface always exists but it's
-// completely no-oped if PE_DEBUG isn't set.
+// almost entirely no-oped if PE_DEBUG isn't set.
 //---
 
 #ifndef __PYTHONEXTRA_DEBUG_H
@@ -19,6 +19,10 @@
 /* Initialize debugging resources (mostly the USB connection). */
 void pe_debug_init(void);
 
+/* Panic with a message (available even if PE_DEBUG=0). */
+void pe_debug_panic(char const *msg)
+__attribute__((noreturn));
+
 /* Print to the debug stream. This function is also called DEBUG_printf in
    MicroPython code. */
 void pe_debug_printf(char const *fmt, ...);
diff --git a/ports/sh/main.c b/ports/sh/main.c
index 8b03e619a..d4776c00d 100644
--- a/ports/sh/main.c
+++ b/ports/sh/main.c
@@ -140,26 +140,27 @@ int main(int argc, char **argv)
     open_generic(&stdouterr_type, pe_shell_console, STDOUT_FILENO);
     open_generic(&stdouterr_type, pe_shell_console, STDERR_FILENO);
 
-    /* Initialize MicroPython */
-    #define HEAP_SIZE 32768
-    void *heap = malloc(32768);
-    if(!heap) {
-        dclear(C_WHITE);
-        dtext(1, 1, C_BLACK, "No heap!");
-        getkey();
-        return 1;
-    }
-
+    /* Initialize the MicroPython GC with most available memory */
     mp_stack_ctrl_init();
-    gc_init(heap, heap + HEAP_SIZE);
-    // TODO: gc_add(start, end) for each area we want to allocate to
-    // fx-9860G III:
-    // * (nothing? x_x)
-    // fx-CG 50:
-    // * The entirety of _uram
-    // * The entirety of the extra VRAM
-    // * Possibly memory past 2M
-    // * (keep the OS heap for normal malloc())
+#ifdef FX9860G
+    /* Get *some* memory from the OS heap */
+    void *gc_area = malloc(32768);
+    if(!gc_area)
+        pe_debug_panic("No heap!");
+    gc_init(gc_area, gc_area + 32768);
+#else
+    /* Get everything from the OS stack (~ 350 ko) */
+    size_t gc_area_size;
+    void *gc_area = kmalloc_max(&gc_area_size, "_ostk");
+    gc_init(gc_area, gc_area + gc_area_size);
+
+    /* Other options:
+       - All of _uram (leaving the OS heap for the shell/GUI/etc)
+       - The OS' extra VRAM
+       - Memory past the 2 MB boundary on tested OSes */
+    // gc_add(start, end)...
+#endif
+
     mp_init();
 
     /* TODO: Add an option for the shorter prompt */