我开始在飞思卡尔 mx5x 板上研究嵌入式设备，现在我正在探索板上的引导模块。根据选择的引导模式，需要正确的 uboot 映像。对于 mmc boot-mod，镜像是 uboot-no-padding.bin，它是从 uboot.bin 生成的。所以，我的问题：为什么需要无填充uboot，两个图像之间的区别是什么？
请帮忙，谢谢
2 回答
0
According to my knowledge, Flash storage devices like SD, NAND and NOR-Flash memories into which images are loaded do not accept images that are smaller than a specific size (128k as minimum size from what I know). If the generated u-boot image is smaller than that threshold, padding must be added in order to be able to load it.
I am using dd command to remove 1k of padding and I got at the end a u-boot.bin with size 128k which is appropriate for loading. I am using a microSD of 4GB. This is brought from my personal experience. Please, take a look at this link. It talks about building and flashing u-boot for colibri target. In the page 6, it talks about u-boot padding.
http://antmicro.com/files/release/u-boot-colibri/U-Boot_Colibri_Manual.pdf
I hope helpful.
于 2013-12-06T09:24:07.863 回答
0
我只是在猜测，但通常 uboot 放在“裸”闪存上，每次写入都发生在擦除块大小量子中。因此，填充 uboot.bin 映像以擦除块大小是有意义的。MMC 是基于闪存的，但闪存由固件管理，因此您不知道（或关心）擦除块大小，因此填充只是无缘无故地使图像变大。
于 2011-12-28T09:43:51.303 回答