Kexec on ARM with LEDE 17.01

Git rev 315afb92ebc20e44a2d20bb4e9ed724418f20b0f. Compiled from source, config has:


No other changes made from defaults.

Target platform is TP-Link Archer C2600 (ipq806x). Attempting to run kexec on the device flashed with this build using a variety of kernels (zImage and uImage tested) results in the following:

kexec -t zImage -d --command-line= --atags -f vmlinux.elf
Try gzip decompression.
Try LZMA decompression.
lzma_decompress_file: read on vmlinux.elf of 65536 bytes failed
kernel: 0xb678e010 kernel_size: 0x71f6a4
00012028b678e010-beaf3ee700000004 (0)
zImage header: 0x05000200 0x00200034 0x00280006
Could not find a free area of memory of 0x7276a4 bytes...
Cannot load vmlinux.elf

However, /proc/iomem shows plenty of free System Ram:

cat /proc/iomem
00108000-00108fff : /soc/rpm@108000
00700000-00700fff : /soc/qfprom@700000
00800000-00803fff : /soc/pinmux@800000
00900000-00903fff : /soc/clock-controller@900000
02011000-02011fff : /soc/clock-controller@2011000
02088000-02088fff : /soc/clock-controller@2088000
0208a000-0208a0ff : /soc/timer@200a000
02098000-02098fff : /soc/clock-controller@2098000
08000000-081fffff : ath
10000000-10007fff : /soc/usb30@1/dwc3@10000000
10000000-10007fff : /soc/usb30@1/dwc3@10000000
1000c100-1000ccff : /soc/usb30@1/dwc3@10000000
100f8800-100f882f : /soc/phy@100f8800
100f8830-100f885f : /soc/phy@100f8830
11000000-11007fff : /soc/usb30@0/dwc3@11000000
11000000-11007fff : /soc/usb30@0/dwc3@11000000
1100c100-1100ccff : /soc/usb30@0/dwc3@11000000
110f8800-110f882f : /soc/phy@110f8800
110f8830-110f885f : /soc/phy@110f8830
16300000-163000ff : /soc/gsbi@16300000
16340000-16340fff : msm_serial
18300000-183fffff : /soc/dma@18300000
1a200000-1a2000ff : /soc/gsbi@1a200000
1a280000-1a280fff : /soc/gsbi@1a200000/spi@1a280000
1a500000-1a5001ff : /soc/rng@1a500000
1b500000-1b500fff : dbi
1b502000-1b50207f : elbi
1b600000-1b6000ff : parf
1b700000-1b700fff : dbi
1b702000-1b70207f : elbi
1b800000-1b8000ff : parf
2e000000-2e1fffff : ath
37200000-373fffff : /soc/ethernet@37200000
37400000-375fffff : /soc/ethernet@37400000
42000000-5fffffff : System RAM
42208000-4278de77 : Kernel code
427c4000-4283ab77 : Kernel data

Has anyone successfully used kexec on ARM recently? Any ideas?