[ELDK] Another BogoMIPS question

[Gao Ya'nan]

Sorry for asking BogoMIPS question, but I have read the FAQ in DULG.

First I use U-Boot-v2009.08 and Linux-2.6.30.3, and only adopt some
necessary code for my MPC875 board from fads, don't change the
configuration related on clock.

But when booting the Linux compiled with mpc885_ads_defconfig, I get
the BogoMIPS value is 6.19, though the processor is running on 50MHz.

The PLPRCR value and whole message are below:

===================================================================

=>md ff000284 1
ff000284: 039a0080    ....

-------------------------------------------------------------------------------------------------------------------------------------

U-Boot 2009.08 (Sep 08 2009 - 17:17:29)
CPU:   MPC885ZPnn at 50 MHz [40.0...133.0 MHz]
       8 kB I-Cache 8 kB D-Cache FEC present
Board: MPC885ADS
DRAM:  (64 MB SDRAM) 64 MB
FLASH: 18 MB
*** Warning - bad CRC, using default environment
In:    serial
Out:   serial
Err:   serial
Net:   FEC ETHERNET
Hit any key to stop autoboot:  0
=>tftp 02000000 uImage
Using FEC ETHERNET device
TFTP from server 192.168.0.1; our IP address is 192.168.0.100
Filename 'uImage'.
Load address: 0x2000000
Loading: #################################################################
         #################################################################
         #################################################################
         #####################
done
Bytes transferred = 1104922 (10dc1a hex)
=>tftp 02400000 mpc875etm.dtb
Using FEC ETHERNET device
TFTP from server 192.168.0.1; our IP address is 192.168.0.100
Filename 'mpc875etm.dtb'.
Load address: 0x2400000
Loading: #
done
Bytes transferred = 4930 (1342 hex)
=>tftp 02200000 uRamdisk_1
Using FEC ETHERNET device
TFTP from server 192.168.0.1; our IP address is 192.168.0.100
Filename 'uRamdisk_1'.
Load address: 0x2200000
Loading: #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         ####################################
done
Bytes transferred = 1846099 (1c2b53 hex)
=>bootm 02000000 02200000 02400000
## Booting kernel from Legacy Image at 02000000 ...
   Image Name:   Linux-2.6.30.3
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    1104858 Bytes =  1.1 MB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
## Loading init Ramdisk from Legacy Image at 02200000 ...
   Image Name:   Simple Embedded Linux Framework
   Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)
   Data Size:    1846035 Bytes =  1.8 MB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
## Flattened Device Tree blob at 02400000
   Booting using the fdt blob at 0x2400000
   Uncompressing Kernel Image ... OK
   Loading Ramdisk to 03d9e000, end 03f60b13 ... OK
   Loading Device Tree to 007fb000, end 007ff341 ... OK
Using Freescale MPC885 ADS machine description
Linux version 2.6.30.3 (xxxxxx at xx.xxx.xxx.xx) (gcc version 4.2.2) #2 Tue Sep
 8 16:25:50 CST 2009
Zone PFN ranges:
  DMA      0x00000000 -> 0x00004000
  Normal   0x00004000 -> 0x00004000
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
    0: 0x00000000 -> 0x00004000
MMU: Allocated 72 bytes of context maps for 16 contexts
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 16256
Kernel command line:
NR_IRQS:512
PID hash table entries: 256 (order: 8, 1024 bytes)
Decrementer Frequency = 0x2faf08
clocksource: timebase mult[50000000] shift[22] registered
console [ttyCPM0] enabled
Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
Memory: 60628k/65536k available (2164k kernel code, 4840k reserved, 100k data, 9
9k bss, 96k init)
Kernel virtual memory layout:
  * 0xffffe000..0xfffff000  : fixmap
  * 0xfde00000..0xfe000000  : consistent mem
  * 0xfddf6000..0xfde00000  : early ioremap
  * 0xc5000000..0xfddf6000  : vmalloc & ioremap
SLUB: Genslabs=12, HWalign=16, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Calibrating delay loop... 6.19 BogoMIPS (lpj=30976)
Mount-cache hash table entries: 512
net_namespace: 296 bytes
NET: Registered protocol family 16
===================================================================