[Arm-netbook] allwinner-v3.0-android-v2 boot up failure(SDCARD)

[Adam Jiang]

Hi, folks

Finally, I got my A2000 board run with allwinner-v3.0-android-v2.
However, it failed before mount rootfs.

[    4.400000] [mmc_pm]: No sdio card, please check your config !!
[    4.430000] Registering SWP/SWPB emulation handler
[    4.440000] registered taskstats version 1
[    4.440000] regulator_init_complete: axp20_buck3: incomplete
constraints, leaving on
[    4.460000] regulator_init_complete: axp20_buck2: incomplete
constraints, leaving on
[    4.470000] regulator_init_complete: axp20_ldo4: incomplete
constraints, leaving on
[    4.490000] regulator_init_complete: axp20_ldo3: incomplete
constraints, leaving on
[    4.500000] regulator_init_complete: axp20_ldo2: incomplete
constraints, leaving on
[    4.520000] regulator_init_complete: axp20_ldo1: incomplete
constraints, leaving on
[    4.530000] sunxi-rtc sunxi-rtc: sunxi_rtc_gettime
[    4.540000] sunxi-rtc sunxi-rtc: read time 2010-1-1 0:0:9
[    4.550000] sunxi-rtc sunxi-rtc: setting system clock to 2010-01-01
00:00:09 UTC (1262304009)
[    4.570000] VFS: Cannot open root device "mmcblk0p2" or unknown-block(0,0)
[    4.580000] Please append a correct "root=" boot option; here are
the available partitions:
[    4.670000] Kernel panic - not syncing: VFS: Unable to mount root
fs on unknown-block(0,0)
[    4.690000] [<c003c1fc>] (dump_backtrace+0x0/0x110) from
[<c05820dc>] (dump_stack+0x18/0x1c)
[    4.710000] [<c05820c4>] (dump_stack+0x0/0x1c) from [<c0582230>]
(panic+0x74/0x188)
[    4.730000] [<c05821bc>] (panic+0x0/0x188) from [<c0008ef8>]
(mount_block_root+0x214/0x2b8)
[    4.750000] [<c0008ce4>] (mount_block_root+0x0/0x2b8) from
[<c00090ec>] (mount_root+0x64/0x68)
[    4.770000] [<c0009088>] (mount_root+0x0/0x68) from [<c0009290>]
(prepare_namespace+0x1a0/0x1e8)
[    4.790000] [<c00090f0>] (prepare_namespace+0x0/0x1e8) from
[<c0008b84>] (kernel_init+0x154/0x158)
[    4.820000] [<c0008a30>] (kernel_init+0x0/0x158) from [<c006c1d0>]
(do_exit+0x0/0x748)

It seems this problem is about sdmmc configuration in script.bin which
is generated by script.fex. I got the fex file by bin2fex utility from
the stock binary. Though I can get some sections in fex file about mmc
, it is very hard to guess the details about these values. Anybody
knows where could I get documentation about fex file? Anyone
experienced SD card boot could shed some light on the following
section? Thanks.

[mmc0_para]
sdc_used        = 1
sdc_detmode     = 1
bus_width       = 4
sdc_d1  = port:PF00<2><1><2><default>
sdc_d0  = port:PF01<2><1><2><default>
sdc_clk = port:PF02<2><1><2><default>
sdc_cmd = port:PF03<2><1><2><default>
sdc_d3  = port:PF04<2><1><2><default>
sdc_d2  = port:PF05<2><1><2><default>
sdc_det = port:PH01<0><1><default><default>
sdc_use_wp      = 0
sdc_wp  =

[mmc1_para]
sdc_used        = 1
sdc_detmode     = 1
bus_width       = 4
sdc_cmd = port:PH22<5><1><2><default>
sdc_clk = port:PH23<5><1><2><default>
sdc_d0  = port:PH24<5><1><2><default>
sdc_d1  = port:PH25<5><1><2><default>
sdc_d2  = port:PH26<5><1><2><default>
sdc_d3  = port:PH27<5><1><2><default>
sdc_det = port:PH02<0><1><default><default>
sdc_use_wp      = 0
sdc_wp  =