How to change U-Boot memory card

Question

U-Boot (2009.03) on the MS104-SH4 has a RAM memory card shown below.

0x8c000000 Not For Use (4kB)
0x8c001000 for Linux kernel and root file system (3MB)
0x8c400000 for Linux process (28MB)

For me, 3MB for the Linux kernel and root file system is too small, because the Linux kernel and ramdisk have 1MB and 3.5MB, respectively. Therefore, I would like to change the memory card, for example, as shown below.

0x8c000000 Not For Use (4KB)
0x8c001000 for Linux kernel and root file system (16MB)
0x8cf60000 for Linux process (16MB)

In my hunch, I have to change the source code of uboot, but cannot find where I have to change. Can someone tell me if u-boot memory card can be changed? If yes, please tell me how to do this. Thank you for your help!

I found a similar question on How to find a device’s memory card? but my SH4 iomem is empty (size 0), so it looks like a different topic.

Answer 1

You can change the U-boot memory card. you need to change the source code of the U-boot. U-boot/include/configs/<board_name.h> is the place where you can configure the memory card. where <board_name.h> is your architecture-specific file and has #define entries that you can change to the desired values. u-boot/arch/<architecture_name>/lib/board.c initialize the memory card.