On 4/30/19 8:13 PM, Atish Patra wrote: > On 4/30/19 2:52 AM, Marek Vasut wrote: >> On 4/30/19 3:27 AM, Atish Patra wrote: >> >> [...] >> >>>>> Yes. FIT image parsing can be done in that way. However, the idea was >>>>> here to load Image.gz directly. Image.gz is default compressed Linux >>>>> kernel image format in RISC-V. >>>> >>>> Sigh, and the image header is compressed as well, so there's no way to >>>> identify the image format, right ? And there's no decompressor, so the >>>> dcompressing has to be done by bootloader, which would need some >>>> sort of >>>> very smart way of figuring out which exact compression method is used ? >>>> >>> Yes. Image.gz is always gunzip. So checking first two bytes is enough to >>> confirm that it is a gz file. >> >> What happens once people start feeding it more exotic compression >> methods, like LZ4 or LZO or LZMA for example ? >> > > booti command help will clearly state that it can only boot kernel from > Image or Image.gz. > > static char booti_help_text[] = > "[addr [initrd[:size]] [fdt]]\n" > - " - boot arm64 Linux Image stored in memory\n" > + " - boot arm64 Linux Image or riscv Linux Image/Image.gz stored > in memory\n"
Obvious question -- does this Image.gz stuff apply to arm64 ? > > (I will update the help text with Image.gz part) > > Anything other than that, it will fail with following error. > > "Bad Linux RISCV Image magic!" Right, so we're implementing file(1)-lite here to detect the format. >>> The tricky part is length of the compressed file. I took another look at >>> the gunzip implementation in U-Boot. It looks like to me that compressed >>> header length just to parse the header correctly. It doesn't actually >>> use the "length" to decompress. In fact, it updates the length with >>> uncompressed bytes after the decompression. >> >> That's possible. >> > > David suggested a better idea. > > 1. User can supply kernel_size and we can store in environment variable. > 2. If the size is empty or greater than CONFIG_SYS_BOOTM_LEN, booti > fails with appropriate error message. You can keep decompressing until you reach $bootm_len, sure . > We will update the documents to add the additional step for Image.gz > > I am fine with either approach. Any preference ? > > Regards, > Atish -- Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot