summaryrefslogtreecommitdiffstats
path: root/qemu/roms/u-boot/doc/README.imx5
diff options
context:
space:
mode:
authorYang Zhang <yang.z.zhang@intel.com>2015-08-28 09:58:54 +0800
committerYang Zhang <yang.z.zhang@intel.com>2015-09-01 12:44:00 +0800
commite44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch)
tree66b09f592c55df2878107a468a91d21506104d3f /qemu/roms/u-boot/doc/README.imx5
parent9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff)
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5 Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/roms/u-boot/doc/README.imx5')
-rw-r--r--qemu/roms/u-boot/doc/README.imx528
1 files changed, 28 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/doc/README.imx5 b/qemu/roms/u-boot/doc/README.imx5
new file mode 100644
index 000000000..c5312b69d
--- /dev/null
+++ b/qemu/roms/u-boot/doc/README.imx5
@@ -0,0 +1,28 @@
+U-Boot for Freescale i.MX5x
+
+This file contains information for the port of U-Boot to the Freescale
+i.MX5x SoCs.
+
+1. CONFIGURATION OPTIONS/SETTINGS
+---------------------------------
+
+1.1 CONFIG_MX51_PLL_ERRATA: Workaround for i.MX51 PLL errata.
+ This option should be enabled by all boards using the i.MX51 silicon
+ version up until (including) 3.0 running at 800MHz.
+ The PLL's in the i.MX51 processor can go out of lock due to a metastable
+ condition in an analog flip-flop when used at high frequencies.
+ This workaround implements an undocumented feature in the PLL (dither
+ mode), which causes the effect of this failure to be much lower (in terms
+ of frequency deviation), avoiding system failure, or at least decreasing
+ the likelihood of system failure.
+
+1.2 CONFIG_SYS_MAIN_PWR_ON: Trigger MAIN_PWR_ON upon startup.
+ This option should be enabled for boards having a SYS_ON_OFF_CTL signal
+ connected to GPIO1[23] and triggering the MAIN_PWR_ON signal like in the
+ reference designs.
+
+2. CONVENTIONS FOR FUSE ASSIGNMENTS
+-----------------------------------
+
+2.1 MAC Address: It is stored in the words 9 to 14 of fuse bank 1, using the
+ natural MAC byte order (i.e. MSB first).