Hammer Linux Board

Recently I’ve been doing some work with a TinCan Tools Hammer embedded Linux board. The hammer board is a neat little piece of hardware in a 40-pin DIP form factor, it looks good from a hardware point of view although unfortunately lacking a bit in the documentation area. I had some recent frustration getting MMC/SD card support to work which turned out to be a problem in the driver, their Linux programmer tracked it down and supplied the new mach-tct_hammer.c file required to fix things from a driver point of view.

Then I had some frustration because using buildroot as per the supplied configuration was giving me different results to the filesystem loaded onto the device at the factory, namely that it ended up being mounted read only. An attempt to remount the root partition read/write complained that /proc/mounts was missing which I was able to solve by adding the following lines to the device_table.txt file:

/proc        d    777    0     0    –    –    –    –    –
/proc/mounts    d    777    0     0    –    –    –    –    –
/proc/devices    d    777    0     0    –    –    –    –    –

Once these lines were included the root filesystem was mounted read/write by default. I then went on to add the following to device_table.txt:

/dev/mmcblk0     b     777     0    0     179     0     –     –     –
/dev/mmcblk0p1     b     777     0    0     179     1     –     –     –
/mnt/mmc    d    777    0    0    –    –    –    –    –

After which I was able to successfully mount a 4GB FAT32 formatted SD card using the command:

mount /dev/mmcblk0p1 /mnt/mmc