MTD设备的逻辑擦除块大小可以增加吗? [英] Can the logical erase block size of an MTD device be increased?
问题描述
jffs2(mtd-utils版本1.5.0,mkfs.jffs2
版本1.60)的最小擦除块大小似乎是8KiB:
The minimum erase block size for jffs2 (mtd-utils version 1.5.0, mkfs.jffs2
revision 1.60) seems to be 8KiB:
Erase size 0x1000 too small. Increasing to 8KiB minimum
但是我正在运行带有at25df321a的Linux 3.10,
However I am running Linux 3.10 with an at25df321a,
m25p80 spi32766.0: at25df321a (4096 Kbytes),
并且擦除块大小仅为4KiB:
and the erase block size is only 4KiB:
mtd5
Name: spi32766.0
Type: nor
Eraseblock size: 4096 bytes, 4.0 KiB
Amount of eraseblocks: 1024 (4194304 bytes, 4.0 MiB)
Minimum input/output unit size: 1 byte
Sub-page size: 1 byte
Character device major/minor: 90:10
Bad blocks are allowed: false
Device is writable: true
有没有办法使mtd系统将多个擦除块视为一个?也许一些ioctl或模块参数?
Is there a way to make the mtd system treat multiple erase blocks as one? Maybe some ioctl or module parameter?
如果我用较大的擦除块大小刷新jffs2图像,则会收到许多内核错误消息,文件丢失甚至有时会出现紧急情况.
If I flash a jffs2 image with larger erase block size, I get lots of kernel error messages, missing files and sometimes panic.
解决方法
我发现flasherase --jffs2
导致4KiB擦除块大小的文件系统正常工作.因此,我入侵了mkfs.jfss2.c
文件,生成的图像似乎正常运行.我会做一些测试.
I found that flasherase --jffs2
results in a working filesystem inspite of the 4KiB erase block size. So I hacked the mkfs.jfss2.c
file and the resulting image seems to work fine. I'll give it some testing.
diff -rupN orig/mkfs.jffs2.c new/mkfs.jffs2.c
--- orig/mkfs.jffs2.c 2014-10-20 15:43:31.751696500 +0200
+++ new/mkfs.jffs2.c 2014-10-20 15:43:12.623431400 +0200
@@ -1659,11 +1659,11 @@ int main(int argc, char **argv)
}
erase_block_size *= units;
- /* If it's less than 8KiB, they're not allowed */
- if (erase_block_size < 0x2000) {
- fprintf(stderr, "Erase size 0x%x too small. Increasing to 8KiB minimum\n",
+ /* If it's less than 4KiB, they're not allowed */
+ if (erase_block_size < 0x1000) {
+ fprintf(stderr, "Erase size 0x%x too small. Increasing to 4KiB minimum\n",
erase_block_size);
- erase_block_size = 0x2000;
+ erase_block_size = 0x1000;
}
break;
}