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Phil Elwellpopcornmix
Phil Elwell
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scripts: Add mkknlimg and knlinfo scripts from tools repo
The Raspberry Pi firmware looks for a trailer on the kernel image to determine whether it was compiled with Device Tree support enabled. If the firmware finds a kernel without this trailer, or which has a trailer indicating that it isn't DT-capable, it disables DT support and reverts to using ATAGs. The mkknlimg utility adds that trailer, having first analysed the image to look for signs of DT support and the kernel version string. knlinfo displays the contents of the trailer in the given kernel image. scripts/mkknlimg: Add support for ARCH_BCM2835 Add a new trailer field indicating whether this is an ARCH_BCM2835 build, as opposed to MACH_BCM2708/9. If the loader finds this flag is set it changes the default base dtb file name from bcm270x... to bcm283y... Also update knlinfo to show the status of the field. scripts/mkknlimg: Improve ARCH_BCM2835 detection The board support code contains sufficient strings to be able to distinguish 2708 vs. 2835 builds, so remove the check for bcm2835-pm-wdt which could exist in either. Also, since the canned configuration is no longer built in (it's a module), remove the config string checking. See: #1157 scripts: Multi-platform support for mkknlimg and knlinfo The firmware uses tags in the kernel trailer to choose which dtb file to load. Current firmware loads bcm2835-*.dtb if the '283x' tag is true, otherwise it loads bcm270*.dtb. This scheme breaks if an image supports multiple platforms. This patch adds '270X' and '283X' tags to indicate support for RPi and upstream platforms, respectively. '283x' (note lower case 'x') is left for old firmware, and is only set if the image only supports upstream builds. scripts/mkknlimg: Append a trailer for all input Now that the firmware assumes an unsigned kernel is DT-capable, it is helpful to be able to mark a kernel as being non-DT-capable. Signed-off-by: Phil Elwell <[email protected]> scripts/knlinfo: Decode DDTK atom Show the DDTK atom as being a boolean. Signed-off-by: Phil Elwell <[email protected]> mkknlimg: Retain downstream-kernel detection With the death of ARCH_BCM2708 and ARCH_BCM2709, a new way is needed to determine if this is a "downstream" build that wants the firmware to load a bcm27xx .dtb. The vc_cma driver is used downstream but not upstream, making vc_cma_init a suitable predicate symbol. mkknlimg: Find some more downstream-only strings See: #1920 Signed-off-by: Phil Elwell <[email protected]> scripts: Update mkknlimg, just in case With the removal of the vc_cma driver, mkknlimg lost an indication that the user had built a downstream kernel. Update the script, adding a few more key strings, in case it is still being used. Note that mkknlimg is now deprecated, except to tag kernels as upstream (283x), and thus requiring upstream DTBs. See: #2239 Signed-off-by: Phil Elwell <[email protected]>
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‎scripts/knlinfo

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#!/usr/bin/env perl
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# ----------------------------------------------------------------------
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# knlinfo by Phil Elwell for Raspberry Pi
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#
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# (c) 2014,2015 Raspberry Pi (Trading) Limited <[email protected]>
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#
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# Licensed under the terms of the GNU General Public License.
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# ----------------------------------------------------------------------
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use strict;
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use integer;
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use Fcntl ":seek";
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my $trailer_magic = 'RPTL';
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my %atom_formats =
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(
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'DDTK' => \&format_bool,
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'DTOK' => \&format_bool,
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'KVer' => \&format_string,
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'270X' => \&format_bool,
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'283X' => \&format_bool,
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'283x' => \&format_bool,
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);
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if (@ARGV != 1)
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{
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print ("Usage: knlinfo <kernel image>\n");
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exit(1);
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}
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my $kernel_file = $ARGV[0];
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my ($atoms, $pos) = read_trailer($kernel_file);
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exit(1) if (!$atoms);
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printf("Kernel trailer found at %d/0x%x:\n", $pos, $pos);
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foreach my $atom (@$atoms)
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{
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printf(" %s: %s\n", $atom->[0], format_atom($atom));
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}
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exit(0);
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sub read_trailer
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{
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my ($kernel_file) = @_;
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my $fh;
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if (!open($fh, '<', $kernel_file))
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{
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print ("* Failed to open '$kernel_file'\n");
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return undef;
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}
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if (!seek($fh, -12, SEEK_END))
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{
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print ("* seek error in '$kernel_file'\n");
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return undef;
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}
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my $last_bytes;
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sysread($fh, $last_bytes, 12);
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my ($trailer_len, $data_len, $magic) = unpack('VVa4', $last_bytes);
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if (($magic ne $trailer_magic) || ($data_len != 4))
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{
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print ("* no trailer\n");
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return undef;
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}
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if (!seek($fh, -12, SEEK_END))
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{
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print ("* seek error in '$kernel_file'\n");
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return undef;
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}
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$trailer_len -= 12;
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while ($trailer_len > 0)
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{
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if ($trailer_len < 8)
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{
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print ("* truncated atom header in trailer\n");
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return undef;
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}
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if (!seek($fh, -8, SEEK_CUR))
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{
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print ("* seek error in '$kernel_file'\n");
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return undef;
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}
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$trailer_len -= 8;
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my $atom_hdr;
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sysread($fh, $atom_hdr, 8);
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my ($atom_len, $atom_type) = unpack('Va4', $atom_hdr);
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if ($trailer_len < $atom_len)
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{
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print ("* truncated atom data in trailer\n");
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return undef;
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}
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my $rounded_len = (($atom_len + 3) & ~3);
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if (!seek($fh, -(8 + $rounded_len), SEEK_CUR))
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{
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print ("* seek error in '$kernel_file'\n");
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return undef;
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}
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$trailer_len -= $rounded_len;
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my $atom_data;
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sysread($fh, $atom_data, $atom_len);
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if (!seek($fh, -$atom_len, SEEK_CUR))
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{
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print ("* seek error in '$kernel_file'\n");
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return undef;
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}
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push @$atoms, [ $atom_type, $atom_data ];
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}
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if (($$atoms[-1][0] eq "\x00\x00\x00\x00") &&
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($$atoms[-1][1] eq ""))
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{
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pop @$atoms;
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}
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else
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{
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print ("* end marker missing from trailer\n");
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}
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return ($atoms, tell($fh));
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}
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sub format_atom
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{
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my ($atom) = @_;
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my $format_func = $atom_formats{$atom->[0]} || \&format_hex;
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return $format_func->($atom->[1]);
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}
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sub format_bool
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{
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my ($data) = @_;
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return unpack('V', $data) ? 'y' : 'n';
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}
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sub format_int
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{
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my ($data) = @_;
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return unpack('V', $data);
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}
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sub format_string
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{
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my ($data) = @_;
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return '"'.$data.'"';
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}
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sub format_hex
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{
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my ($data) = @_;
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return unpack('H*', $data);
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}

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