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Diffstat (limited to 'target/linux/realtek/files/rtkload/README')
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diff --git a/target/linux/realtek/files/rtkload/README b/target/linux/realtek/files/rtkload/README deleted file mode 100644 index 236e144a1..000000000 --- a/target/linux/realtek/files/rtkload/README +++ /dev/null @@ -1,115 +0,0 @@ -hfload is a simple, second stage ELF bootloader for the VTech Helio. -It is probably generalizable to other Philips R3912 devices with a -friendly boot rom and flash. - -It works on both real Helio hardware and the Helio emulator. - -LEGAL STUFF -=========== - -This software is subject to the terms and conditions of the GNU -General Public License. See the file "COPYING" in the main directory -of this archive for more details. - -Copyright (C) 2000 by Jay Carlson. - -Many files originated in the Linux kernel. - -Note that my intent is that the last two stages of the build process -(production of the ELF memory image, and conversion to a raw ROM -image) are "mere aggregation [...] on a volume of a storage or -distribution medium" in the sense of the last paragraph of section 2 -of the GPL. If necessary, I will arrange that the aggregation -mechanism is "/bin/cat" or a simple C program, if anyone has a problem -with my use of a "linker" to throw together files in a single box. No -real linking is done at this stage; the Linux kernel is treated as -pure data. - -QUICK START -=========== - -Point the Makefile at your kernel build directory. If building for -the emulator, uncomment the EMULATOR line in the Makefile. - -If you don't have a romdisk image, touch romdisk. - -Put the first 64K of a 2M VT-OS rom image in "vtboot"; if you're -building for the real hardware you can fake it with "make fake-vtboot". - -"make" produces "tryrom" and "linux.bin". tryrom is a full 2M ROM -image for the emulator containing the VTOS bootloader, hfload, a -compressed stripped copy of your vmlinux, and the contents of romdisk. -linux.bin is a 2M-128k OS upgrade image without the VTOS bootloader, -suitable for use with the VTech "dt.exe" flash programming tool. - -WHAT IT DOES -============ - -On startup, the VT-OS bootroom sets up the hardware a little, installs -a 4k stack, and jumps to 0x9fc10000 in ROM. hfload begins here. - -Setup ------ - -start.S zeroes the hfload bss area. It moves the stack to somewhere -more spacious (paranoia), and jumps to main(). (It should turn on the -serial port too.) - -main() immediately prints a message on serial port A. (It used to try -to initialize the Helio LCD hardware, but that's commented out now.) - -Decompression -------------- - -The contents of the input_data-input_data_end region are gunzip'd from -flash to the 4M mark in memory, at the start of the second DRAM bank. - -input_data typically points to a gzip'd stripped Linux kernel. - -ELF load --------- - -main() reads in the ELF header from the decompressed data. -(Currently, the only error checking is verification that the declared -sizes of structures match the expected sizes; this catches most -errors.) The ELF image is copied to its destinations declared in the -program headers, and excess memory is properly zeroed. - -Kernel start ------------- - -main() hands the ELF entry address to start.S:start_kernel. -start_kernel places the address of the romdisk area at 0x80030000, -restores the stack, and calls entry_address(0,0,0). - -WHY THE IMAGE READ FUNCTIONS ARE SO UGLY -======================================== - -I originally debugged this application as a userland binary, reading -the image from a file descriptor. I then realized I could mmap() the -kernel image. The restrictions on read_struct, copy_to_region, and -seek_forward came out of this. As it turns out, the "can only seek -forward, must be aligned" characteristics may be useful in the future. -There's no reason why the entire kernel has to be uncompressed as a -big blob; the stream reading functions could be rewritten to process -the 32k decompressed windows as a coroutine to the decompression -process. ELF images over about 2M are going to need this. - -WHY THIS WHOLE APP IS SO UGLY -============================= - -Most of this will be rewritten once I understand better what I'm -trying to do. Why make throwaway code pretty? - -VTBOOT -====== - -The file "vtboot" is not included with this distribution. It is an -image of the VTech VT-OS bootloader that's hardwired into real Helio -devices. It's the first 64k of a full VT-OS rom image. Given such a -rom image, it can be extracted by: - - dd if=VTOS-1-1-03.rom of=vtboot bs=64k count=1 - -If you're building for the real hardware, you don't need this file. -"make fake-vtboot" produces 64k of zeroes. |