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Diffstat (limited to 'doc/README.nokia_rx51')
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diff --git a/doc/README.nokia_rx51 b/doc/README.nokia_rx51 new file mode 100644 index 00000000000..a8fdfcd372a --- /dev/null +++ b/doc/README.nokia_rx51 @@ -0,0 +1,104 @@ +Board: Nokia RX-51 aka N900 + +This board definition results in a u-boot.bin which can be chainloaded +from NOLO in qemu or on a real N900. It does very little hardware config +because NOLO has already configured the board. Only needed is enabling +internal eMMC memory via twl4030 regulator which is not enabled by NOLO. + +NOLO is expecting a kernel image and will treat any image it finds in +onenand as such. This u-boot is intended to be flashed to the N900 like +a kernel. In order to transparently boot the original kernel, it will be +appended to u-boot.bin at 0x40000. NOLO will load the entire image into +(random) memory and execute u-boot, which saves hw revision, boot reason +and boot mode ATAGs set by NOLO. Then the bootscripts will attempt to load +uImage or boot.scr from a fat, ext2/ext3 or ext4 filesystem in external +SD card or internal eMMC memory. If this fails or keyboard is closed then +the appended kernel image will be booted using some generated and some +stored ATAGs (see boot order). + +There is support for hardware watchdog. Hardware watchdog is started by +NOLO so u-boot must kick watchdog to prevent reboot device (but not very +often, max every 2 seconds). There is also support for framebuffer display +output with ANSI espace codes and the N900 HW keyboard input. USB tty works +but is disabled because it prevents the current Maemo kernel from booting. + +When U-Boot is starting it enable IBE bit in Auxiliary Control Register, +which is needed for Thumb-2 ISA support. It is workaround for errata 430973. + +Default boot order: + + * 0. if keyboard is closed boot automatically attached kernel image + * 1. try boot from external SD card + * 2. try boot from internal eMMC memory + * 3. try boot from attached kernel image + +Boot from SD or eMMC in this order: + + * 1. + * 1.1 find boot.scr on first fat partition + * 1.2 find uImage on first fat parition + * 1.3 same order for 2. - 4. fat partition + * 2. same as 1. but for ext2/3 partition + * 3. same as 1. but for ext4 partition + + +Available additional commands/variables: + + * run sercon - Use serial port for control + * run usbcon - Use usbtty for control + * run vgacon - Use framebuffer and HW keyboard for control (default) + + * run sdboot - Boot from external SD card (see boot order) + * run emmcboot - Boot from internal eMMC memory (see boot order) + * run attachboot - Boot attached kernel image (attached to U-Boot binary) + + * run scriptload - Load boot script ${mmcscriptfile} + * run scriptboot - Run loaded boot script + * run kernload - Load kernel image ${mmckernfile} + * run initrdload - Load initrd image ${mmcinitrdfile} + * run kernboot - Boot loaded kernel image + * run kerninitrdboot - Boot loaded kernel image with loaded initrd image + + * run trymmcscriptboot - Try to load and boot script ${mmcscriptfile} + * run trymmckernboot - Try to load and boot kernel image ${mmckernfile} + * run trymmckerninitrdboot - Try to load and boot kernel image ${mmckernfile} + with initrd image ${mmcinitrdfile} + +Additional variables for loading files from mmc: + + * mmc ${mmcnum} (0 - external, 1 - internal) + * partition number ${mmcpart} (1 - 4) + * parition type ${mmctype} (fat, ext2) + +Additional varuables for booting kernel: + + * setup_omap_atag - Add OMAP table into atags structure (needs maemo kernel) + * setup_console_atag - Enable serial console in OMAP table + * setup_boot_reason_atag - Change boot reason in OMAP table + * setup_boot_mode_atag - Change boot mode in OMAP table + +USB TTY: + + Maemo kernel 2.6.28 will crash if u-boot enable usb tty. So USB TTY is disabled. + For enabling USB TTY just add this line to file include/configs/nokia_rx51.h + + #define CONFIG_USB_TTY + + +ONENAND support: + + ONENAND support is disabled because not working yet and cause linux kernel to + crash or no access to mtd. For enabling ONENAND support add this line at begin + of file include/configs/nokia_rx51.h + + #define ONENAND_SUPPORT + + +UBIFS support: + + UBIFS support is disabled, because U-Boot image is too big and cannot be + flashed with attached zImage to RX-51 kernel nand area. For enabling UBIFS + support first enable ONENAND support and then add this line at begin of file + include/configs/nokia_rx51.h + + #define UBIFS_SUPPORT |