What I remember is omap3 have 64k SRAM , omap4 have 32k SRAM ,dm8148/j4/j5 have SRAM ,dm8168 have 256k am335x have 64k SRAM
2015-01-25 13:03 GMT+08:00 Robert Nelson <[email protected]>: > > On Jan 24, 2015 10:56 PM, "liyaoshi" <[email protected]> wrote: > > > > If I understand correctly > > Boot rom dont care about the FAT table . its only read first several > blocks > > generally , MLO should be on the 2nd block ,1st block is MBR , > > But if there is a FAT file system . 2nd block should be fat table , > > 3nd block should be MLO > > > > whats my failed boot experience is when you format a sd card ,then copy > a dummy file first ,then copy MLO to fat partiton > > this will cause boot failed > > > > and if you try another way , fdisk from 10M an create only one ext4 > partiton > > dd if=MLO of=/dev/sdb bs=512 seek=2 > > this still boot mlo ,but no u-boot.bin , this only because u-boot source > code > > > > Actually , if you check QNX ipl source code , they dont need any FAT > > > > And if you really want a customed u-boot , > > You can get it minimized lower than 64K and boot kernel directly > > Mainline u-boot also doesn't require 'fat', on omap4+ you can also use > ext, as long as mlo is copied first. For omap3 there isn't enough SRAM so > it can be either fat or ext.... > > > > > > > 2015-01-24 3:40 GMT+08:00 Robert Nelson <[email protected]>: > >> > >> > yup, i realize that now. is this behaviour documented somewhere in > >> > an official TI am335x/omap4+ reference manual somewhere? > >> > >> It tis.. under "raw mode".. > >> > >> Regards, > >> > >> -- > >> Robert Nelson > >> http://www.rcn-ee.com/ > >> > >> -- > >> For more options, visit http://beagleboard.org/discuss > >> --- > >> You received this message because you are subscribed to the Google > Groups "BeagleBoard" group. > >> To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected]. > >> For more options, visit https://groups.google.com/d/optout. > > > > > > -- > > For more options, visit http://beagleboard.org/discuss > > --- > > You received this message because you are subscribed to the Google > Groups "BeagleBoard" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected]. > > For more options, visit https://groups.google.com/d/optout. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
