On 25/09/2012 00:23, Troy Kisky wrote:
The advantages of a plugin over spl are
- smaller code 0x190 bytes, plus the table.
relying on the ROM to do the heavy lifting.
This is true. However, as you are writing in the next line, the bootROM boots from devices having much more space as some bytes. Even on small SPI-NOR (the smallest device I used with MX5), this was not an issue.
On the other side, you cannot influence the behavior of the bootROM, and much more job is let to the bootROM, less possibilities to fix some things. SPL is part of U-Boot, all sources are availbale and it is easier to fix.
- support all boot modes that the ROM does. NOR/NAND/ONENAND/MMC/eMMC
Hard Disk and SSD devices using SATA Serial ROM through SPI/I2C
I do not know about booting from SATA, if a plugin is a must - but this means that it fixes a problem in the bootROM. Apart of that, there are no hardware limitation that avoi to use SPL with these media devices.
- Easy to switch back to previous DCD tables
for debugging or permanently. I can see that many people will never use either plugin or SPL
I think you are talking specifically about mainlined i.MX boards. This is correct, because patches to make SPL available will be merged now. But if we see U-Boot in its globality, quite all TI's boards have a SPL.
and will stick with the current method, or have separate cfg files for each processor type. I could still have the separate cfg files #include a common file. ie #define FOR_MX6Q #include "imx-common.cfg"
Using common file is a practice we should improve, definitely. But it has nothing to do with plugin. Agree that similar boards and / or SOCs should better share code.
#define FOR_MX6DL #include "imx-common.cfg"
- plugin method is already working.
ok, this is right
Let me know which features might make it to mainline
- variable length headers
Absolutely yes !
- parsing of cfg to pull the file, instead of push
- C preprocessor
Yes, I agree with you that it is useful. As you said, using #define make it more readable.
- expression evaluation.
As you posted previously, this depends on plugin.
5 plugins
Currently, I do not see that plugin is strictly required and can move iMX away from the rest of U-Boot development.
and I'll post a new series.
Ok, thanks.
Best regards, Stefano