Changes in kernel/arch/mips32/src/mm/frame.c [9d58539:3c50cddc] in mainline

File:

• kernel/arch/mips32/src/mm/frame.c (modified) (4 diffs)

kernel/arch/mips32/src/mm/frame.c

@@ -40 +40 @@
 #include <mm/asid.h>
 #include <config.h>
+#ifdef MACHINE_msim
 #include <arch/drivers/msim.h>
+#endif
+#include <arch/arch.h>
 #include <print.h>
 
@@ -84 +87 @@
                 return false;
 #endif
-        
-#if defined(MACHINE_lgxemul) || defined(MACHINE_bgxemul)
-        /* gxemul devices */
-        if (overlaps(frame << ZERO_PAGE_WIDTH, ZERO_PAGE_SIZE,
-            0x10000000, MiB2SIZE(256)))
+
+#if defined(MACHINE_lmalta) || defined(MACHINE_bmalta)
+        if (frame >= (sdram_size >> ZERO_PAGE_WIDTH))
                 return false;
 #endif
@@ -225 +226 @@
                                         if (ZERO_PAGE_VALUE != 0xdeadbeef)
                                                 avail = false;
-#if defined(MACHINE_lgxemul) || defined(MACHINE_bgxemul)
-                                        else {
-                                                ZERO_PAGE_VALUE_KSEG1(frame) = 0xaabbccdd;
-                                                if (ZERO_PAGE_VALUE_KSEG1(frame) != 0xaabbccdd)
-                                                        avail = false;
-                                        }
-#endif
                                 }
                         }
@@ -247 +241 @@
         /* Blacklist interrupt vector frame */
         frame_mark_unavailable(0, 1);
+
+#if defined(MACHINE_lmalta) || defined(MACHINE_bmalta)
+        /* Blacklist memory regions used by YAMON.
+         *
+         * The YAMON User's Manual vaguely says the following physical addresses
+         * are taken by YAMON:
+         *
+         * 0x1000       YAMON functions
+         * 0x5000       YAMON code
+         *
+         * These addresses overlap with the beginning of the SDRAM so we need to
+         * make sure they cannot be allocated.
+         *
+         * The User's Manual unfortunately does not say where does the SDRAM
+         * portion used by YAMON end.
+         *
+         * Looking into the YAMON 02.21 sources, it looks like the first free
+         * address is computed dynamically and depends on the size of the YAMON
+         * image. From the YAMON binary, it appears to be 0xc0d50 or roughly
+         * 772 KiB for that particular version.
+         *
+         * Linux is linked to 1MiB which seems to be a safe bet and a reasonable
+         * upper bound for memory taken by YAMON. We will use it too.
+         */
+        frame_mark_unavailable(0, 1024 * 1024 / FRAME_SIZE);
+#endif
         
         /* Cleanup */