我想在物理内存中保留一个页面，以便内核不会为其他任何内容分配它。标准解决方案是使用memmap。我在我的uboot参数（memmap = 4K $ 0xA4D000）中定义了它，但它没有生效。我已经验证了从/ proc / commandline传递给内核的完整参数。是否需要启用任何内核配置？
*uname -a
Linux hostname 3.12.19-rt30 #5 SMP Thu Sep 1 23:23:49 IST 2016 ppc64 GNU/Linux*
*cat /proc/cmdline
root=/dev/mtdblock9 rw rootfstype=jffs2 init=/init siq_board_type=CU_200103 default_hugepagesz=256m hugepagesz=256m hugepages=1 usdpaa_mem=256M bportals=s0 qportals=s0 isolcpus=1,2,3,4,7 DEBUG_MODE=y memmap=4K$0xA4D000 memblock=debug console=ttyS1,115200 HOSTNAME=airv_cu PRIPART=4 ip=10.208.26.101:10.204.1.3:10.208.26.254:255.255.255.0:airv_cu:eth0:off panic=1*
cat /proc/iomem
00000000-bfffffff : System RAM
fe8000000-fefffffff : fe8000000.nor
ffe008000-ffe008fff : mpc85xx_mc_err
ffe009000-ffe009fff : mpc85xx_mc_err
ffe11c500-ffe11c507 : serial
ffe11c600-ffe11c607 : serial
ffe11d500-ffe11d507 : serial
ffe11d600-ffe11d607 : serial
ffe1e0000-ffe1e07ff : rman-inbound-block0
ffe1e0b00-ffe1e0fff : rman-uio
ffe1e1000-ffe1e17ff : rman-inbound-block1
ffe1e2000-ffe1e27ff : rman-inbound-block2
ffe1e3000-ffe1e37ff : rman-inbound-block3
ffe400000-ffe4fffff : fman
ffe400000-ffe47ffff : fman-muram
ffe482000-ffe482fff : fman-port-hc
ffe483000-ffe483fff : fman-port-hc
ffe484000-ffe484fff : fman-port-hc
ffe485000-ffe485fff : fman-port-hc
ffe486000-ffe486fff : fman-port-hc
ffe487000-ffe487fff : fman-port-hc
ffe488000-ffe488fff : fman-port-hc
ffe489000-ffe489fff : fman-port-hc
ffe48a000-ffe48afff : fman-port-hc
ffe48b000-ffe48bfff : fman-port-hc
ffe48c000-ffe48cfff : fman-port-hc
ffe48d000-ffe48dfff : fman-port-hc
ffe490000-ffe490fff : fman-port-hc
ffe491000-ffe491fff : fman-port-hc
ffe4a8000-ffe4a8fff : fman-port-hc
ffe4a9000-ffe4a9fff : fman-port-hc
ffe4aa000-ffe4aafff : fman-port-hc
ffe4ab000-ffe4abfff : fman-port-hc
ffe4ac000-ffe4acfff : fman-port-hc
ffe4ad000-ffe4adfff : fman-port-hc
ffe4b0000-ffe4b0fff : fman-port-hc
ffe4b1000-ffe4b1fff : fman-port-hc
ffe4dc000-ffe4dcfff : fman-vsp
ffe4e0000-ffe4e0fff : mac
ffe4e2000-ffe4e2fff : mac
ffe4e4000-ffe4e4fff : mac
ffe4e6000-ffe4e6fff : mac
ffe4fe000-ffe4fefff : fman-rtc