diff options
Diffstat (limited to 'target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch')
| -rw-r--r-- | target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch b/target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch new file mode 100644 index 0000000000..0030a7da4f --- /dev/null +++ b/target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch @@ -0,0 +1,66 @@ +From b6d850fe4035d6bee7199119358e06f802aa19ed Mon Sep 17 00:00:00 2001 +From: Hauke Mehrtens <hauke@hauke-m.de> +Date: Sun, 18 Jul 2010 12:49:41 +0200 +Subject: [PATCH 1/5] MIPS: BCM47xx: Really fix 128MB RAM problem + +The previews patch 84a6fcb368a080620d12fc4d79e07902dbee7335 was wrong, +I got wrong success reports. + +The bcm47xx architecture maps the ram into a 128MB address space. It +will be paced there as often as goes into the 128MB. The detection +tries to find the position where the same memory is found. When reading +over 128MB the processor will throw an exception. If 128MB ram is +installed, it will not find the same memory because it tries to read +over the 128MB boarder. Now it just assumes 128MB installed ram if it +can not find that the ram is repeating. + +Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> +--- + arch/mips/bcm47xx/prom.c | 22 ++++++++++++++-------- + 1 files changed, 14 insertions(+), 8 deletions(-) + +--- a/arch/mips/bcm47xx/prom.c ++++ b/arch/mips/bcm47xx/prom.c +@@ -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. + * +@@ -134,21 +135,26 @@ 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; + } + +- /* 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); + } + |