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Diffstat (limited to 'target/linux/brcm47xx/patches-2.6.30/170-128MB_ram_bugfix.patch')
-rw-r--r--target/linux/brcm47xx/patches-2.6.30/170-128MB_ram_bugfix.patch43
1 files changed, 29 insertions, 14 deletions
diff --git a/target/linux/brcm47xx/patches-2.6.30/170-128MB_ram_bugfix.patch b/target/linux/brcm47xx/patches-2.6.30/170-128MB_ram_bugfix.patch
index e54e3de409..93f4b1f101 100644
--- a/target/linux/brcm47xx/patches-2.6.30/170-128MB_ram_bugfix.patch
+++ b/target/linux/brcm47xx/patches-2.6.30/170-128MB_ram_bugfix.patch
@@ -1,17 +1,32 @@
--- a/arch/mips/bcm47xx/prom.c
+++ b/arch/mips/bcm47xx/prom.c
-@@ -141,6 +141,14 @@ static __init void prom_init_mem(void)
- break;
- }
-
-+ /* Ignoring the last page when ddr size is 128M. Cached
-+ * accesses to last page is causing the processor to prefetch
-+ * using address above 128M stepping out of the ddr address
-+ * space.
-+ */
-+ if (mem == 0x8000000)
-+ mem -= 0x1000;
-+
- add_memory_region(0, mem, BOOT_MEM_RAM);
- }
+@@ -126,6 +126,7 @@ static __init void prom_init_cmdline(voi
+ static __init void prom_init_mem(void)
+ {
+ unsigned long mem;
++ unsigned long max;
+ /* Figure out memory size by finding aliases.
+ *
+@@ -134,8 +135,21 @@ static __init void prom_init_mem(void)
+ * want to reuse the memory used by CFE (around 4MB). That means cfe_*
+ * functions stop to work at some point during the boot, we should only
+ * call them at the beginning of the boot.
++ *
++ * BCM47XX uses 128MB for addressing the ram, if the system contains
++ * less that that amount of ram it remaps the ram more often into the
++ * available space.
++ * Accessing memory after 128MB will cause an exception.
++ * max contains the biggest possible address supported by the platform.
++ * If the method wants to try something above we assume 128MB ram.
+ */
++ max = ((unsigned long)(prom_init) | ((128 << 20) - 1));
+ for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
++ if (((unsigned long)(prom_init) + mem) > max) {
++ mem = (128 << 20);
++ printk("assume 128MB RAM\n");
++ break;
++ }
+ if (*(unsigned long *)((unsigned long)(prom_init) + mem) ==
+ *(unsigned long *)(prom_init))
+ break;