On Sep 23, 2009, at 2:20 AM, Mingkai Hu wrote: > MPC8536E can support booting from NAND flash which uses the > image u-boot-nand.bin. This image contains two parts: a 4K > NAND loader and a main U-Boot image. The former is appended > to the latter to produce u-boot-nand.bin. The 4K NAND loader > includes the corresponding nand_spl directory, along with the > code twisted by CONFIG_NAND_SPL. The main U-Boot image just > like a general U-Boot image except the parts that included by > CONFIG_SYS_RAMBOOT. > > When power on, eLBC will automatically load from bank 0 the > 4K NAND loader into the FCM buffer RAM where CPU can execute > the boot code directly. In the first stage, the NAND loader > copies itself to RAM or L2SRAM to free up the FCM buffer RAM, > then loads the main image from NAND flash to RAM or L2SRAM > and boot from it. > > This patch implements the NAND loader to load the main image > into L2SRAM, so the main image can configure the RAM by using > SPD EEPROM. In the first stage, the NAND loader copies itself > to the second to last 4K address space, and uses the last 4K > address space as the initial RAM for stack. > > Obviously, the size of L2SRAM shouldn't be less than the size > of the image used. If so, the workaround is to generate another > image that includes the code to configure the RAM by SPD and > load it to L2SRAM first, then relocate the main image to RAM > to boot up. > > Signed-off-by: Mingkai Hu <mingkai...@freescale.com> > --- > > Change over v3: > - Intergrated Scott's comments. > - Intergrated Wolfgang's comments.
applied to 85xx - k _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
