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System software for the Simputer

The boot loader : Blob
The boot loader used on the simputer is called blob. Blob for the simputer is based on blob from the LART project (blob-1.0.8-pre2). Blob for the simputer is present at offset 0 on the flash of the simputer, and is responsible for loading the kernel and ramdisk images from flash to DRAM. It also displays a logo on the LCD of the simputer when it is loading the kernel and ramdisk. This logo is also stored on the flash and can be replaced by your favourite logo too. Blob is distributed under the GNU GPL.

Source of blob for the simputer: blob-1.0.8-pre2-simp1.tar.gz

Binary image of blob for arm: blob-1.0.8-pre2-simp1.gz

Image of the blob logo: logo.gz

The Simputer Linux kernel
The Linux kernel for the Simputer is based on the arm patches to the Linux kernel (maintained by Russel King and Nicolas Pitre). This has been modified to work on the Simputer. The current kernel version is 2.4.0-test8-rmk5-np2. We are currently moving to 2.4.3, and work is in progress. The source code includes the drivers for flash, audio for UCB1200, keypad on the simputer, and simputer touch screen and frame buffer. Currently, the download is not in a convenient patch format. This will be shortly made available. The current download is a tarball of the entire kernel source, patched for the simputer. The Simputer Linux kernel is distributed under the GNU GPL.

Source tarball of the Linux kernel: 2.4.0-test8-rmk5-np2.tar.gz

Binary image of the Linux kernel: zImage-2.4.0-test8-rmk5-np2.gz

The Ramdisk image
The Ramdisk image is transferred to DRAM by blob, during boot time, and is used by the kernel as a root file system on ramdisk. It contains the GNU C library and associated libraries, a shell (bash), busybox, various startup scripts and a flash driver to mount the flash file system. The Ramdisk image is a compressed ext2 file system created using the loopback file system.

Ramdisk image: ramdisk.gz

The flash file system
The flash file system on the simputer contains libraries required for XFree86 clients (libX11, libXaw, libXt...), Perl 5.5, Perl/Tk, perl modules required for IMLI (XML::Parser, MIME::Base64), rxvt, xclock, chimera, Tapatap, wmx, kernel drivers for the simputer, all compiled for the arm. The flash file system is an ext2 file system mounted on /usr/local by the startup scripts of the Simputer. It also includes various X11 fonts that are required by the applications. All the programs in this distribution follow their individual copyrights and licensing.

Flash file system: usr.tar.gz

Location of system software on the Simputer flash
Component Offset Flash partition
blob 0x00000000 /dev/flh0
logo 0x00010000 /dev/flh1
kernel 0x00020000 /dev/flh2
ramdisk 0x000E0000 /dev/flh3
/usr/local ext2 fs 0x003DC000 /dev/flh4

People involved:

V Vinay (
Swami Manohar (
Vivek K S (
Ajit Anvekar (
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