5.3 Linux Support

24

Linux boot command line parameters to the kernel also helps here. Typical usage includes is of the following form, which supplies both the MTD partition information and the root filesystem reference:

mtdparts=phys_mapped_flash:1024k(armboot),256k(params),-(rootfs1) root=/dev/mtdblock3 rootfstype=cramfs

In English, this reads as something like:

MTD partitions are 1MB (named armboot), 256K(named params), with the remainder of flash named rootfs1. The root filesystem is in the third partition, and its’ type is cramfs.

Mounting a JFFS2 image is done in the same manner, except the rootfstype parameter has a value of jffs2.

The U-Boot boot loader supports copying data from RAM to flash for upgrades and such. Refer to the unprotect, erase, and cp commands for details.

A third means of mounting one of these root filesystems is to use a loop device. In Linux jargon, a loop device is a file that contains a filesystem within it. Both the initrd and cramfs images may be used in this fashion as shown in the following examples.

Mount a cramfs file (by far the simplest case).

~ $ sudo mount -o loop -t cramfs ~/cramfs.img /mnt/cramfs

Mount an ext2 image (Only slightly harder because mmcinitrd is actually gzipped and needs to be gunzip’d first).

~$ cp -f mmcinitrd mmc.img.gz

~$ gunzip mmc.img.gz

~$ sudo mount -o loop -t ext2 ~/mmc.img /mnt/ext2

To mount a JFFS2 image a bit more is needed. Your kernel needs to have mtd and mtdblock support compiled in or installed as modules. Then, a mtdram device can be created, you can copy the JFFS2 data to it and mount the device.

The Handhelds site has more information on the topic.

~ $ sudo /sbin/insmod mtdram total_size=32768 erase_size=256

Using /lib/modules/2.4.23_pre8-gss-r2/kernel/drivers/mtd/devices/mtdram.o

~$ sudo dd if=jffs2.img of=/dev/mtd0 10809+1 records in

10809+1 records out

~$ sudo /sbin/insmod mtdblock

Using /lib/modules/2.4.23_pre8-gss-r2/kernel/drivers/mtd/mtdblock.o

~$ sudo mount -r -t jffs2 /dev/mtdblock/0 /mnt/jffs2/

~$ ls /mnt/jffs2/

bin etc lib linuxrc opt proc sbin sysfs tmp usr var

December 28, 2005

Revision 2.8

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Image 24
Sonic Alert 2.8 user manual December 28

2.8 specifications

Sonic Alert 2.8 is a state-of-the-art alarm clock designed primarily for individuals with hearing impairments or those who simply require a more robust waking mechanism. Engineered to deliver high-performance features and proprietary technologies, this device stands out as a reliable solution for a restful night and an efficient morning wake-up.

One of the hallmark features of Sonic Alert 2.8 is its powerful bed shaker. This vibration mechanism is designed to be placed under your pillow or mattress, providing a tactile wake-up signal. For individuals who may not respond to traditional auditory alarms, this function ensures that they start their day without being late for appointments or commitments.

The alarm clock also boasts an impressive sound output. With adjustable volume settings, users can customize the alarm sound to their preference, ranging from gentle melodies to loud, attention-grabbing beeps. This flexibility caters to diverse user needs, allowing for a more personalized waking experience.

In terms of visibility, Sonic Alert 2.8 integrates a bright, flashing strobe light that works in conjunction with the auditory alarms. This visual cue appeals to those who may have difficulty hearing and can be beneficial in noisy environments. The strobe light can be set to flash in a specific pattern or color, adding another layer of customization to the waking experience.

Moreover, Sonic Alert 2.8 is engineered with a user-friendly interface, featuring large, easy-to-read display numbers that are perfect for the visually impaired. The intuitive buttons allow for straightforward operation, including setting alarms or toggling through various functions with minimal hassle.

The device is also equipped with a battery backup feature, ensuring that alarms will still sound even during power outages. This functionality provides peace of mind, knowing that important morning engagements won't be missed.

Additionally, Sonic Alert 2.8 is constructed with durable materials, making it a reliable companion for years to come. The sleek design and compact size make it easy to place on any bedside table without taking up excessive space.

Overall, Sonic Alert 2.8 exemplifies innovation in alarm technology, combining advanced features and thoughtful design to cater to users' unique needs. Whether for the hard of hearing or anyone who simply desires a more effective wake-up method, this alarm clock is an ideal choice.