Author: Tom

Embedded firmware developer, sometimes Linux kernel developer.

UBI Fastmap on the Devkit8000

Tonight I tried the (new) UBI Fastmap feature on the Devkit8000.

For this reason I created a UBI image with ptxdist. The UBI fastmap was not activated in the kernel that installed the UBI image in NAND.

After first boot I got the following output:

[ 2.842315] UBI: attaching mtd5 to ubi0
[ 3.146972] UBI: scanning is finished
[ 3.165374] UBI: attached mtd5 (name "File System", size 121 MiB) to ubi0

That make around 300 ms from “attaching…” to “attached …”.

Then I activated UBI fastmap in the kernel configuration and got the following output:

[ 2.839019] UBI: default fastmap pool size: 45
[ 2.843780] UBI: default fastmap WL pool size: 25
[ 2.848754] UBI: attaching mtd5 to ubi0
[ 3.154663] UBI: scanning is finished
[ 3.173156] UBI: attached mtd5 (name "File System", size 121 MiB) to ubi0

After changing the bootargs in the bootloader U-Boot and adding ubi.fm_autoconvert=1 there is nothing to see from conversion:

[ 2.839019] UBI: default fastmap pool size: 45
[ 2.843780] UBI: default fastmap WL pool size: 25
[ 2.848754] UBI: attaching mtd5 to ubi0
[ 3.154663] UBI: scanning is finished
[ 3.173156] UBI: attached mtd5 (name "File System", size 121 MiB) to ubi0

But with the next boot ubi fastmap is active:

[ 2.844116] UBI: default fastmap pool size: 45
[ 2.848876] UBI: default fastmap WL pool size: 25
[ 2.853820] UBI: attaching mtd5 to ubi0
[ 2.927093] UBI: attached by fastmap
[ 2.930877] UBI: fastmap pool size: 45
[ 2.934844] UBI: fastmap WL pool size: 25
[ 2.953826] UBI: attached mtd5 (name "File System", size 121 MiB) to ubi0

That are around 100 ms from “attaching …” to “attached…”. For such a small UBIFS with only 121 MiB is it a gain of 200 ms.

Debugging U-Boot after relocation

My ~/.gdbinit

target remote 192.168.11.200:2001
monitor reset halt

Type in gdb:

(gdb)monitor reset halt
(gdb)continue

Output in terminal:

U-Boot 2013.04-rc3-dirty (Apr 16 2013 - 14:33:48)

OMAP36XX/37XX-GP ES1.2, CPU-OPP2, L3-165MHz, Max CPU Clock 1 Ghz
OMAP3 Tricorder + LPDDR/NAND
I2C: ready
DRAM: 256 MiB
NAND: 512 MiB
MMC: OMAP SD/MMC: 0
*** Warning – bad CRC, using default environment

In: serial
Out: serial
Err: serial
Die ID #065a00229e38000001683b0601020024
Hit any key to stop autoboot: 0
OMAP3 Tricorder #

In U-Boot type:

OMAP3 Tricorder # bdinfo
arch_number = 0x00000BE2
boot_params = 0x80000100
DRAM bank = 0x00000000
-> start = 0x80000000
-> size = 0x10000000
DRAM bank = 0x00000001
-> start = 0x90000000
-> size = 0x00000000
baudrate = 115200 bps
TLB addr = 0x8FFF0000
relocaddr = 0x8FF67000
reloc off = 0x0FE67000
irq_sp = 0x8FE66F38
sp start = 0x8FE66F28
OMAP3 Tricorder #

So we get the relocation address of U-Boot: 0x8FF67000
And in gdb we can load the symbol-file:

Program received signal SIGSTOP, Stopped (signal).
0x8ff90554 in ?? ()
(gdb) add-symbol-file u-boot 0x8ff67000
add symbol table from file "u-boot" at
.text_addr = 0x8ff67000
(y or n) y
Reading symbols from /home/tweber/build/tricorder/u-boot/u-boot...done.
(gdb)

Simple test, set breakpoint @ do_version:

(gdb) b do_bdinfo
Breakpoint 1 at 0x8ff6a680: file cmd_bdinfo.c, line 373.
(gdb) c
Continuing.

In U-Boot type version:

OMAP3 Tricorder # bdinfo

And in gdb the breakpoint is hit:

Breakpoint 1, do_bdinfo (cmdtp=0x8ffbc048, flag=0, argc=1, argv=0x8fe76090) at cmd_bdinfo.c:373
373 {
(gdb)

Boot times (part 2)

The candidates are this time: gzip, lzma, lzo, xz and uncompressed.
The boot time is measured with grabserial. The image is read from a sd card.

compression method image size loading time decompression time
gzip 3978136 0.327381 0.744222
lzma 2939704 0.245322 2.41247
lzo 4368056 no boot
xz 2792912 0.220659 1.961494
uncompressed 7967108 0.641257 –

Test network speed

One of my actual projects uses a USB-Ethernet (LAN9512) interface. So I am interested in the real speed for this combination.

On the embedded device I used netcat with the following parameters:
nc -l -p 1234 | dd of=/dev/null

And on the host side I used netcat with:
dd if=/dev/urandom bs=4096 count=100000 | nc host.tld 1234

For the different counts I got the following numbers

count duration speed
1000 1 s 4.1 MB/s
10000 10.8 s 3.8 MB/s
100000 108 s 3.8 MB/s
1000000 1092 s 3.7 MB/s

Okay, the last test copied 4.1 GB and lasted 18 minutes.