install-novatek: the first install from the vendor U-Boot, step by step

en/install-novatek.md

@@ -4,24 +4,68 @@
 For XM vendor boards with NT98562 and NT98566 SoC ONLY!!!
 ---------------------------------------------------------
 
+### What is supported
+
+- XM vendor boards whose U-Boot prompt is `nvt@na51089:`. The vendor U-Boot
+  stays on flash; only the kernel and the root filesystem are replaced.
+- NOR flash of 8 MB or more. Anything past 8 MB goes to the settings partition.
+- Sensors with video: SC401AI, SC500AI and SC501AI. With any other sensor the
+  camera boots and is reachable on the network, but has no video.
+- Images: `openipc.nt98562-nor-lite.tgz` and `openipc.nt98566-nor-lite.tgz`.
+  The NT98566 image has been checked on hardware; the NT98562 one is built from
+  the same tree but has not been tested on a camera yet. Reports are welcome.
+
 ### Initial device firmware update
 
-> **This section will be completed at the end of the research**
+You need a UART console and a TFTP server on the camera's network.
+
+1. Back up the whole flash first and keep the copy off the camera, as described
+   in [Backing up stock firmware](backup-stock-firmware.md). U-Boot on these
+   boards cannot send a backup over the network, so use a programmer or the
+   stock firmware's shell.
+2. Download the archive for your SoC, for example
+   https://github.com/OpenIPC/firmware/releases/download/latest/openipc.nt98562-nor-lite.tgz,
+   and put the `uImage.<soc>` and `rootfs.squashfs.<soc>` files from it in the
+   TFTP root.
+3. Power the camera on while pressing Ctrl-C on the console until the
+   `nvt@na51089:` prompt appears; the boot delay is zero, so a single key press
+   is usually too late. Then enter, with your own addresses and SoC:
 
 ```
-run uk; run ur; reset            # Flash kernel, rootfs and reboot device
+setenv ipaddr 192.168.1.10
+setenv serverip 192.168.1.254
+setenv soc nt98562
+setenv osmem 32M
+setenv bootargs 'earlyprintk console=ttyS0,115200 mem=${osmem} panic=20 nprofile_irq_duration=on root=/dev/mtdblock3 rootfstype=squashfs init=/init mtdparts=spi_nor.0:64k(loader),256k(boot),2048k(kernel),5120k(rootfs),-(rootfs_data)'
+setenv bootcmd 'setenv setargs setenv bootargs ${bootargs};run setargs;sf probe 0;sf read 0x03100000 0x50000 0x200000;nvt_boot'
+setenv uk 'mw.b 0x01000000 ff 1000000;tftp 0x01000000 uImage.${soc} && sf probe 0 && sf erase 0x50000 0x200000 && sf write 0x01000000 0x50000 ${filesize}'
+setenv ur 'mw.b 0x01000000 ff 1000000;tftp 0x01000000 rootfs.squashfs.${soc} && sf probe 0 && sf erase 0x250000 0x500000 && sf write 0x01000000 0x250000 ${filesize}'
+saveenv
+run uk && run ur && reset
 ```
 
+   Each `run` must end with `Written: OK`. If a download or a write fails, the
+   line stops there: nothing more is erased and the camera does not reset. Fix
+   the TFTP side and run the line again.
+4. The settings partition still holds what the stock firmware left there and
+   has to be formatted once. A freshly flashed camera is unclaimed and has no
+   shell, so log in as `root` on the console or over SSH with no password,
+   answer the one-time setup prompt, and run `firstboot`. It formats the
+   partition and reboots.
+5. `firstboot` also erases the password you just set, so the camera comes back
+   unclaimed. Claim it for good: open its web page to set the root password and
+   accept the licence, or log in over SSH or the console again. See
+   [Factory reset and the unclaimed camera](first-boot.md).
+
 ### Follow-up quick updates
 
+From the U-Boot prompt, with the new files in the TFTP root:
+
 ```
-run uk; run ur; reset
+run uk && run ur && reset
 ```
 
-### Notes
-
-After you have finished flashing new firmware, please run `firstboot` command
-to format `jffs2` partition used to store settings.
+Or run `sysupgrade` on a running camera.
 
 ### Memory split: `osmem` and `mem=`