diff options
| -rw-r--r-- | target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c b/target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c index f635b4a6c6..c9745746c1 100644 --- a/target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c +++ b/target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c @@ -21,25 +21,32 @@ void __init prom_init(int argc, const char **argv) { unsigned long mem; + unsigned long max; mips_machgroup = MACH_GROUP_BRCM; mips_machtype = MACH_BCM947XX; - /* Figure out memory size by finding aliases */ + /* Figure out memory size by finding aliases + * + * 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); } |