Hi Andre,
On 27 July 2015 at 11:08, Andre Przywara andre.przywara@arm.com wrote:
Hi Simon,
On 24/06/15 00:29, Simon Glass wrote:
diff --git a/doc/README.rockchip b/doc/README.rockchip new file mode 100644 index 0000000..a34e198 --- /dev/null +++ b/doc/README.rockchip
....
+Future work +===========
+Immediate priorities are:
+- MMC support (in U-Boot itself)
Can you briefly sketch what is missing here? If I got this correctly, the SPL part has MMC working, right? If that works, we should be able to load a kernel from the SD card, shouldn't we?
Yes but it is untested. I suspect there will be a few issues but it should not be hard to figure out.
Cheers, Andre.
P.S. Is there any news on the oversized SPL image? I disabled LED support in the SPL for the time being, so the resulting image is 32189 Bytes (vanilla GCC 5.1.0) and it works for me now.
Does that GCC have the bug fix?
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54303 https://gcc.gnu.org/ml/gcc-patches/2015-05/msg00509.html
It will be a few weeks before I get back to this sorry.
Regards, Simon
+- GPIO (driver exists but is lightly tested) +- I2C (driver exists but is non-functional) +- USB host +- USB device +- PMIC and regulators (only ACT8846 is supported at present) +- LCD and HDMI +- Run CPU at full speed +- Ethernet +- NAND flash +- Support for other Rockchip parts +- Boot U-Boot proper over USB OTG (at present only SPL works)
+Development Notes +=================
+There are plenty of patches in the links below to help with this work.
+[1] https://github.com/rkchrome/uboot.git +[2] https://github.com/linux-rockchip/u-boot-rockchip.git branch u-boot-rk3288 +[3] https://github.com/linux-rockchip/rkflashtool.git +[4] http://wiki.t-firefly.com/index.php/Firefly-RK3288/Serial_debug/en
+rkimage +-------
+rkimage.c produces an SPL image suitable for sending directly to the boot ROM +over USB OTG. This is a very simple format - just the string RK32 (as 4 bytes) +followed by u-boot-spl-dtb.bin.
+The boot ROM loads image to 0xff704000 which is in the internal SRAM. The SRAM +starts at 0xff700000 and extends to 0xff718000 where we put the stack.
+rksd +----
+rksd.c produces an image consisting of 32KB of empty space, a header and +u-boot-spl-dtb.bin. The header is defined by 'struct header0_info' although +most of the fields are unused by U-Boot. We just need to specify the +signature, a flag and the block offset and size of the SPL image.
+The header occupies a single block but we pad it out to 4 blocks. The header +is encoding using RC4 with the key 7c4e0304550509072d2c7b38170d1711. The SPL +image can be encoded too but we don't do that.
+The maximum size of u-boot-spl-dtb.bin which the boot ROM will read is 32KB, +or 0x40 blocks. This is a severe and annoying limitation. There may be a way +around this limitation, since there is plenty of SRAM, but at present the +board refuses to boot if this limit is exceeded.
+The image produced is padded up to a block boundary (512 bytes). It should be +written to the start of an SD card using dd.
+Since this image is set to load U-Boot from the SD card at block offset, +CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR, dd should be used to write +u-boot-dtb.img to the SD card at that offset. See above for instructions.
+rkspi +-----
+rkspi.c produces an image consisting of a header and u-boot-spl-dtb.bin. The +resulting image is then spread out so that only the first 2KB of each 4KB +sector is used. The header is the same as with rksd and the maximum size is +also 32KB (before spreading). The image should be written to the start of +SPI flash.
+See above for instructions on how to write a SPI image.
+Device tree and driver model +----------------------------
+Where possible driver model is used to provide a structure to the +functionality. Device tree is used for configuration. However these have an +overhead and in SPL with a 32KB size limit some shortcuts have been taken. +In general all Rockchip drivers should use these features, with SPL-specific +modifications where required.
+-- +Simon Glass sjg@chromium.org +24 June 2015