brcm2708: make it boot on revision 2 raspberry pis

  * update the bootcode.bin to the newest version
    - gpu/cpu mem split is now configured through config.txt, so no need
      to create more than one sd card image (just edit the config.txt)
    - bootcode.bin now supports the never revision 2 raspberry pis

  * add a commented prepopulated config.txt for easier config changes
    Taken from <https://github.com/Evilpaul/RPi-config>

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36668 3c298f89-4303-0410-b956-a3cf2f4a3e73

2 files changed, 924 insertions, 9 deletions

diff --git a/target/linux/brcm2708/image/Makefile b/target/linux/brcm2708/image/Makefile
index a8dbef1b81..6b4cf141a6 100644
--- a/target/linux/brcm2708/image/Makefile
+++ b/target/linux/brcm2708/image/Makefile
@@ -20,17 +20,17 @@ define Image/Build/RaspberryPi
 
 	mkdosfs $(KDIR)/boot.img -C $(FAT32_BLOCKS)
 	# Raspberry Pi has no bootloader, instead the GPU loads and starts the kernel
-	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/arm128_start.elf ::
-	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/arm192_start.elf ::
-	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/arm224_start.elf ::
 	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/bootcode.bin ::
 	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/COPYING.linux ::
 	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/LICENCE.broadcom ::
-	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/loader.bin ::
-	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/arm$(2)_start.elf ::start.elf  #Copy file for memory/gpu division
+	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/start.elf ::
+	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/start_cd.elf ::
+	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/fixup.dat ::
+	mcopy -i $(KDIR)/boot.img $(BUILD_DIR)/brcm2708-gpu-fw-boot/fixup_cd.dat ::
 	mcopy -i $(KDIR)/boot.img cmdline.txt ::
+	mcopy -i $(KDIR)/boot.img config.txt ::
 	mcopy -i $(KDIR)/boot.img $(KDIR)/Image ::kernel.img  # Copy OpenWrt built kernel
-	./gen_rpi_sdcard_img.sh $(BIN_DIR)/$(IMG_PREFIX)-sdcard-vfat-$(1)_$(2).img $(KDIR)/boot.img $(KDIR)/root.$(1) \
+	./gen_rpi_sdcard_img.sh $(BIN_DIR)/$(IMG_PREFIX)-sdcard-vfat-$(1).img $(KDIR)/boot.img $(KDIR)/root.$(1) \
 		$(CONFIG_BRCM2708_SD_BOOT_PARTSIZE) $(CONFIG_TARGET_ROOTFS_PARTSIZE)
 endef
 
@@ -38,9 +38,7 @@ define Image/Build
 	$(CP) $(KDIR)/root.$(1) $(BIN_DIR)/$(IMG_PREFIX)-$(1).img
 	$(CP) $(KDIR)/Image $(BIN_DIR)/$(IMG_PREFIX)-Image
 
-	$(call Image/Build/RaspberryPi,$(1),128)
-	$(call Image/Build/RaspberryPi,$(1),192)
-	$(call Image/Build/RaspberryPi,$(1),224)
+	$(call Image/Build/RaspberryPi,$(1))
 endef
 
 $(eval $(call BuildImage))
diff --git a/target/linux/brcm2708/image/config.txt b/target/linux/brcm2708/image/config.txt
new file mode 100644
index 0000000000..36685e9f36
--- /dev/null
+++ b/target/linux/brcm2708/image/config.txt
@@ -0,0 +1,917 @@
+################################################################################
+##  Raspberry Pi Configuration Settings
+##
+##  Revision 14, 2012/10/22
+##
+##  Details taken from the eLinux wiki
+##  For up-to-date information please refer to wiki page.
+##
+##  Wiki Location : http://elinux.org/RPi_config.txt
+##
+##
+##  Description:
+##    Details of each setting are described with each section that begins with
+##    a double hashed comment ('##')
+##    It is up to the user to remove the single hashed comment ('#') from each
+##    option they want to enable, and to set the specific value of that option.
+##
+##  WARNING: Setting the following combination of parameters will set a
+##  permanent bit within the SOC and your warranty is void.
+##    over_voltage>0, and at least one of the following:
+##      force_turbo=1
+##      current_limit_override=0x5A000020
+##      temp_limit>85
+##
+##  Overclock settings will be disabled at runtime if the SoC reaches temp_limit
+##
+################################################################################
+
+################################################################################
+##  Standard Definition Video Settings
+################################################################################
+
+## sdtv_mode
+##     defines the TV standard for composite output
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Normal NTSC (Default)
+##     1        Japanese version of NTSC - no pedestal
+##     2        Normal PAL
+##     3        Brazilian version of PAL - 525/60 rather than 625/50, different
+##              subcarrier
+##
+#sdtv_mode=0
+
+## sdtv_aspect
+##     defines the aspect ratio for composite output
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     1        4:3 (Default)
+##     2        14:9
+##     3        16:9
+##
+#sdtv_aspect=1
+
+## sdtv_disable_colourburst
+##     Disables colour burst on composite output. The picture will be
+##     monochrome, but possibly sharper
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Colour burst is enabled (Default)
+##     1        Colour burst is disabled
+##
+#sdtv_disable_colourburst=1
+
+################################################################################
+##  High Definition Video Settings
+################################################################################
+
+## hdmi_safe
+##     Use "safe mode" settings to try to boot with maximum hdmi compatibility.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Disabled (Default)
+##     1        Enabled (this does: hdmi_force_hotplug=1, config_hdmi_boost=4,
+##                                  hdmi_group=1, hdmi_mode=1,
+##                                  disable_overscan=0)
+##
+#hdmi_safe=1
+
+## hdmi_force_hotplug
+##     Pretends HDMI hotplug signal is asserted so it appears a HDMI display
+##     is attached
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Disabled (Default)
+##     1        Use HDMI mode even if no HDMI monitor is detected
+##
+#hdmi_force_hotplug=1
+
+## hdmi_ignore_hotplug
+##     Pretends HDMI hotplug signal is not asserted so it appears a HDMI
+##     display is not attached
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Disabled (Default)
+##     1        Use composite mode even if HDMI monitor is detected
+##
+#hdmi_ignore_hotplug=1 
+
+## hdmi_drive
+##     chooses between HDMI and DVI modes
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     1        Normal DVI mode (No sound)
+##     2        Normal HDMI mode (Sound will be sent if supported and enabled)
+##
+#hdmi_drive=2
+
+## hdmi_ignore_edid
+##     Enables the ignoring of EDID/display data
+##
+#hdmi_ignore_edid=0xa5000080
+
+## hdmi_edid_file
+##     Read the EDID data from the edid.dat file instead of from the attached
+##     device
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Read EDID data from attached device (Default)
+##     1        Read EDID data from edid.txt file
+##
+#hdmi_edid_file=1
+
+## hdmi_force_edid_audio
+##     Pretends all audio formats are supported by display, allowing
+##     passthrough of DTS/AC3 even when not reported as supported.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Use EDID provided values (Default)
+##     1        Pretend all audio formats are supported
+##
+#hdmi_force_edid_audio=1
+
+## avoid_edid_fuzzy_match
+##     Avoid fuzzy matching of modes described in edid.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Use fuzzy matching (Default)
+##     1        Avoid fuzzy matching
+##
+#avoid_edid_fuzzy_match=1
+
+## hdmi_group
+##     Defines the HDMI type
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Use the preferred group reported by the edid (Default)
+##     1        CEA
+##     2        DMT
+##
+#hdmi_group=1
+
+## hdmi_mode
+##     defines screen resolution in CEA or DMT format
+##
+##     H means 16:9 variant (of a normally 4:3 mode).
+##     2x means pixel doubled (i.e. higher clock rate, with each pixel repeated
+##                                  twice)
+##     4x means pixel quadrupled (i.e. higher clock rate, with each pixel
+##                                     repeated four times)
+##     reduced blanking means fewer bytes are used for blanking within the data
+##                      stream (i.e. lower clock rate, with fewer wasted bytes)
+##
+##     Value    hdmi_group=CEA                  hdmi_group=DMT
+##     -------------------------------------------------------------------------
+##     1        VGA                             640x350   85Hz
+##     2        480p  60Hz                      640x400   85Hz
+##     3        480p  60Hz  H                   720x400   85Hz
+##     4        720p  60Hz                      640x480   60Hz
+##     5        1080i 60Hz                      640x480   72Hz
+##     6        480i  60Hz                      640x480   75Hz
+##     7        480i  60Hz  H                   640x480   85Hz
+##     8        240p  60Hz                      800x600   56Hz
+##     9        240p  60Hz  H                   800x600   60Hz
+##     10       480i  60Hz  4x                  800x600   72Hz
+##     11       480i  60Hz  4x H                800x600   75Hz
+##     12       240p  60Hz  4x                  800x600   85Hz
+##     13       240p  60Hz  4x H                800x600   120Hz
+##     14       480p  60Hz  2x                  848x480   60Hz
+##     15       480p  60Hz  2x H                1024x768  43Hz  DO NOT USE
+##     16       1080p 60Hz                      1024x768  60Hz
+##     17       576p  50Hz                      1024x768  70Hz
+##     18       576p  50Hz  H                   1024x768  75Hz
+##     19       720p  50Hz                      1024x768  85Hz
+##     20       1080i 50Hz                      1024x768  120Hz
+##     21       576i  50Hz                      1152x864  75Hz
+##     22       576i  50Hz  H                   1280x768        reduced blanking
+##     23       288p  50Hz                      1280x768  60Hz
+##     24       288p  50Hz  H                   1280x768  75Hz
+##     25       576i  50Hz  4x                  1280x768  85Hz
+##     26       576i  50Hz  4x H                1280x768  120Hz reduced blanking
+##     27       288p  50Hz  4x                  1280x800        reduced blanking
+##     28       288p  50Hz  4x H                1280x800  60Hz
+##     29       576p  50Hz  2x                  1280x800  75Hz
+##     30       576p  50Hz  2x H                1280x800  85Hz
+##     31       1080p 50Hz                      1280x800  120Hz reduced blanking
+##     32       1080p 24Hz                      1280x960  60Hz
+##     33       1080p 25Hz                      1280x960  85Hz
+##     34       1080p 30Hz                      1280x960  120Hz reduced blanking
+##     35       480p  60Hz  4x                  1280x1024 60Hz
+##     36       480p  60Hz  4x H                1280x1024 75Hz
+##     37       576p  50Hz  4x                  1280x1024 85Hz
+##     38       576p  50Hz  4x H                1280x1024 120Hz reduced blanking
+##     39       1080i 50Hz  reduced blanking    1360x768  60Hz
+##     40       1080i 100Hz                     1360x768  120Hz reduced blanking
+##     41       720p  100Hz                     1400x1050       reduced blanking
+##     42       576p  100Hz                     1400x1050 60Hz
+##     43       576p  100Hz H                   1400x1050 75Hz
+##     44       576i  100Hz                     1400x1050 85Hz
+##     45       576i  100Hz H                   1400x1050 120Hz reduced blanking
+##     46       1080i 120Hz                     1440x900        reduced blanking
+##     47       720p  120Hz                     1440x900  60Hz
+##     48       480p  120Hz                     1440x900  75Hz
+##     49       480p  120Hz H                   1440x900  85Hz
+##     50       480i  120Hz                     1440x900  120Hz reduced blanking
+##     51       480i  120Hz H                   1600x1200 60Hz
+##     52       576p  200Hz                     1600x1200 65Hz
+##     53       576p  200Hz H                   1600x1200 70Hz
+##     54       576i  200Hz                     1600x1200 75Hz
+##     55       576i  200Hz H                   1600x1200 85Hz
+##     56       480p  240Hz                     1600x1200 120Hz reduced blanking
+##     57       480p  240Hz H                   1680x1050       reduced blanking
+##     58       480i  240Hz                     1680x1050 60Hz
+##     59       480i  240Hz H                   1680x1050 75Hz
+##     60                                       1680x1050 85Hz
+##     61                                       1680x1050 120Hz reduced blanking
+##     62                                       1792x1344 60Hz
+##     63                                       1792x1344 75Hz
+##     64                                       1792x1344 120Hz reduced blanking
+##     65                                       1856x1392 60Hz
+##     66                                       1856x1392 75Hz
+##     67                                       1856x1392 120Hz reduced blanking
+##     68                                       1920x1200       reduced blanking
+##     69                                       1920x1200 60Hz
+##     70                                       1920x1200 75Hz
+##     71                                       1920x1200 85Hz
+##     72                                       1920x1200 120Hz reduced blanking
+##     73                                       1920x1440 60Hz
+##     74                                       1920x1440 75Hz
+##     75                                       1920x1440 120Hz reduced blanking
+##     76                                       2560x1600       reduced blanking
+##     77                                       2560x1600 60Hz
+##     78                                       2560x1600 75Hz
+##     79                                       2560x1600 85Hz
+##     80                                       2560x1600 120Hz reduced blanking
+##     81                                       1366x768  60Hz
+##     82                                       1080p     60Hz
+##     83                                       1600x900        reduced blanking
+##     84                                       2048x1152       reduced blanking
+##     85                                       720p      60Hz
+##     86                                       1366x768        reduced blanking
+##
+#hdmi_mode=1
+
+## config_hdmi_boost
+##     configure the signal strength of the HDMI interface.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        (Default)
+##     1
+##     2
+##     3
+##     4        Try if you have interference issues with HDMI
+##     5
+##     6
+##     7        Maximum
+##
+#config_hdmi_boost=0
+
+## hdmi_ignore_cec_init
+##     Doesn't sent initial active source message.  Avoids bringing
+##     (CEC enabled) TV out of standby and channel switch when rebooting.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Normal behaviour (Default)
+##     1        Doesn't sent initial active source message
+##
+#hdmi_ignore_cec_init=1
+
+## hdmi_ignore_cec
+##     Pretends CEC is not supported at all by TV.
+##     No CEC functions will be supported.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Normal behaviour (Default)
+##     1        Pretend CEC is not supported by TV
+##
+#hdmi_ignore_cec=1
+
+################################################################################
+##  Overscan Video Settings
+################################################################################
+
+## overscan_left
+##     Number of pixels to skip on left
+##
+#overscan_left=0
+
+## overscan_right
+##     Number of pixels to skip on right
+##
+#overscan_right=0
+
+## overscan_top
+##     Number of pixels to skip on top
+##
+#overscan_top=0
+
+## overscan_bottom
+##     Number of pixels to skip on bottom
+##
+#overscan_bottom=0
+
+## disable_overscan
+##     Set to 1 to disable overscan
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Overscan Enabled (Default)
+##     1        Overscan Disabled
+##
+#disable_overscan=1
+
+################################################################################
+##  Framebuffer Video Settings
+################################################################################
+
+## framebuffer_width
+##     Console framebuffer width in pixels. Default is display width minus
+##     overscan.
+##
+#framebuffer_width=0
+
+## framebuffer_height
+##     Console framebuffer height in pixels. Default is display height minus
+##     overscan.
+##
+#framebuffer_height=0
+
+## framebuffer_depth
+##     Console framebuffer depth in bits per pixel.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     8        Valid, but default RGB palette makes an unreadable screen
+##     16       (Default)
+##     24       Looks better but has corruption issues as of 2012/06/15
+##     32       Has no corruption issues but needs framebuffer_ignore_alpha=1
+##              and shows the wrong colors as of 2012/06/15
+##
+#framebuffer_depth=16
+
+## framebuffer_ignore_alpha
+##     Set to 1 to disable alpha channel. Helps with 32bit.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Enable Alpha Channel (Default)
+##     1        Disable Alpha Channel
+##
+#framebuffer_ignore_alpha=0
+
+################################################################################
+##  General Video Settings
+################################################################################
+
+## display_rotate
+##     Rotate the display clockwise or flip the display.
+##     The 90 and 270 degrees rotation options require additional memory on GPU,
+##     so won't work with the 16M GPU split.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        0 degrees (Default)
+##     1        90 degrees
+##     2        180 degrees
+##     3        270 degrees
+##     0x10000  Horizontal flip
+##     0x20000  Vertical flip
+##
+#display_rotate=0
+
+################################################################################
+##  Licensed Codecs
+##
+##  Hardware decoding of additional codecs can be enabled by purchasing a
+##  license that is locked to the CPU serial number of your Raspberry Pi.
+##
+##  Up to 8 licenses per CODEC can be specified as a comma seperated list.
+##
+################################################################################
+
+## decode_MPG2
+##     License key to allow hardware MPEG-2 decoding.
+##
+#decode_MPG2=0x12345678
+
+## decode_WVC1
+##     License key to allow hardware VC-1 decoding.
+##
+#decode_WVC1=0x12345678
+
+################################################################################
+##  Test Settings
+################################################################################
+
+## test_mode
+##     Enable test sound/image during boot for manufacturing test.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Disable Test Mod (Default)
+##     1        Enable Test Mode
+##
+#test_mode=0
+
+################################################################################
+##  Memory Settings
+################################################################################
+
+## disable_l2cache
+##     Disable arm access to GPU's L2 cache. Needs corresponding L2 disabled
+##     kernel.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Enable L2 Cache (Default)
+##     1        Disable L2 cache
+##
+#disable_l2cache=0
+
+## gpu_mem
+##     GPU memory allocation in MB for all board revisions.
+##
+##     Default 64
+##
+#gpu_mem=128
+
+## gpu_mem_256
+##     GPU memory allocation in MB for 256MB board revision.
+##     This option overrides gpu_mem.
+##
+#gpu_mem_256=128
+
+## gpu_mem_512
+##     GPU memory allocation in MB for 512MB board revision.
+##     This option overrides gpu_mem.
+##
+#gpu_mem_512=128
+
+################################################################################
+##  Boot Option Settings
+################################################################################
+
+## disable_commandline_tags
+##     Stop start.elf from filling in ATAGS (memory from 0x100) before
+##     launching kernel
+##
+#disable_commandline_tags=0
+
+## cmdline (string)
+##     Command line parameters. Can be used instead of cmdline.txt file
+##
+#cmdline=""
+
+## kernel (string)
+##     Alternative name to use when loading kernel.
+##
+#kernel=""
+
+## kernel_address
+##     Address to load kernel.img file at
+##
+#kernel_address=0x00000000
+
+## ramfsfile (string)
+##     ramfs file to load
+##
+#ramfsfile=""
+
+## ramfsaddr
+##     Address to load ramfs file at
+##
+#ramfsaddr=0x00000000
+
+## initramfs (string address)
+##     ramfs file and address to load it at (it's like ramfsfile+ramfsaddr in
+##     one option).
+##
+##     NOTE: this option uses different syntax than all other options - you
+##           should not use "=" character here.
+##
+#initramfs initramf.gz 0x00800000
+
+## device_tree_address
+##     Address to load device_tree at
+##
+#device_tree_address=0x00000000
+
+## init_uart_baud
+##     Initial uart baud rate.
+##
+##     Default 115200
+##
+#init_uart_baud=115200
+
+## init_uart_clock
+##     Initial uart clock.
+##
+##     Default 3000000 (3MHz)
+##
+#init_uart_clock=3000000
+
+## init_emmc_clock
+##     Initial emmc clock, increasing this can speedup your SD-card.
+##
+##     Default 100000000 (100mhz)
+##
+#init_emmc_clock=100000000
+
+## boot_delay
+##     Wait for a given number of seconds in start.elf before loading
+##     kernel.img.
+##
+##     delay = (1000 * boot_delay) + boot_delay_ms
+##
+##     Default 1
+##
+#boot_delay=0
+
+## boot_delay_ms
+##     Wait for a given number of milliseconds in start.elf before loading
+##     kernel.img.
+##
+##     delay = (1000 * boot_delay) + boot_delay_ms
+##
+##     Default 0
+##
+#boot_delay_ms=0
+
+## avoid_safe_mode
+##     Adding a jumper between pins 5 & 6 of P1 enables a recovery Safe Mode.
+##     If pins 5 & 6 are used for connecting to external devices (e.g. GPIO),
+##     then this setting can be used to ensure Safe Mode is not triggered.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Respect Safe Mode input (Default)
+##     1        Ignore Safe Mode input
+##
+#avoid_safe_mode=1
+
+################################################################################
+##  Overclocking Settings
+##
+##  ARM, SDRAM and GPU each have their own PLLs and can have unrelated
+##  frequencies.
+##
+##  The GPU core, h264, v3d and isp share a PLL, so need to have related
+##  frequencies.
+##  pll_freq = floor(2400 / (2 * core_freq)) * (2 * core_freq)
+##  gpu_freq = pll_freq / [even number]
+##
+##  The effective gpu_freq is automatically rounded to nearest even integer, so
+##  asking for core_freq = 500 and gpu_freq = 300 will result in divisor of
+##  2000/300 = 6.666 => 6 and so 333.33MHz.
+##
+##
+##  Standard Profiles:
+##                  arm_freq    core_freq    sdram_freq    over_voltage
+##     -------------------------------------------------------------------------
+##     None         700         250          400           0
+##     Modest       800         300          400           0
+##     Medium       900         333          450           2
+##     High         950         450          450           6
+##     Turbo        1000        500          500           6
+##
+################################################################################
+
+## force_turbo
+##     Control the kernel "ondemand" governor. It has no effect if no overclock
+##     settings are specified.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Enable dynamic clocks and voltage for the ARM core, GPU core and
+##              SDRAM (Default).
+##              Overclocking of h264_freq, v3d_freq and isp_freq is ignored.
+##     1        Disable dynamic clocks and voltage for the ARM core, GPU core
+##              and SDRAM.
+##              Overclocking of h264_freq, v3d_freq and isp_freq is allowed.
+##
+#force_turbo=0
+
+## initial_turbo
+##     Enables turbo mode from boot for the given value in seconds (up to 60)
+##     or until cpufreq sets a frequency. Can help with sdcard corruption if
+##     overclocked.
+##
+##     Default 0
+##
+#initial_turbo=0
+
+## temp_limit
+##     Overheat protection. Sets clocks and voltages to default when the SoC
+##     reaches this Celsius value.
+##     Setting this higher than default voids warranty.
+##
+##     Default 85
+##
+#temp_limit=85
+
+## arm_freq
+##     Frequency of ARM in MHz.
+##
+##     Default 700.
+##
+#arm_freq=700
+
+## arm_freq_min
+##     Minimum frequency of ARM in MHz (used for dynamic clocking).
+##
+##     Default 700.
+##
+#arm_freq_min=700
+
+## gpu_freq
+##     Sets core_freq, h264_freq, isp_freq, v3d_freq together.
+##
+##     Default 250.
+##
+#gpu_freq=250
+
+## core_freq
+##     Frequency of GPU processor core in MHz. It has an impact on ARM
+##     performance since it drives L2 cache.
+##
+##     Default 250.
+##
+#core_freq=250
+
+## core_freq_min
+##     Minimum frequency of GPU processor core in MHz (used for dynamic
+##     clocking). It has an impact on ARM performance since it drives L2 cache.
+##
+##     Default 250.
+##
+#core_freq_min=250
+
+## h264_freq
+##     Frequency of hardware video block in MHz.
+##
+##     Default 250.
+##
+#h264_freq=250
+
+## isp_freq
+##     Frequency of image sensor pipeline block in MHz.
+##
+##     Default 250.
+##
+#isp_freq=250
+
+## v3d_freq
+##     Frequency of 3D block in MHz.
+##
+##     Default 250.
+##
+#v3d_freq=250
+
+## sdram_freq
+##     Frequency of SDRAM in MHz.
+##
+##     Default 400.
+##
+#sdram_freq=400
+
+## sdram_freq_min
+##     Minimum frequency of SDRAM in MHz (used for dynamic clocking).
+##
+##     Default 400.
+##
+#sdram_freq_min=400
+
+## avoid_pwm_pll
+##     Unlink core_freq from the rest of the gpu. Analog audio should still
+##     work, but from a fractional divider, so lower quality.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     0        Linked core_freq (Default)
+##     1        Unlinked core_freq
+##
+#avoid_pwm_pll=1
+
+################################################################################
+##  Voltage Settings
+################################################################################
+
+## current_limit_override
+##     Disables SMPS current limit protection. Can help if you are currently
+##     hitting a reboot failure when overclocking too high.
+##
+#current_limit_override=0x5A000020
+
+## over_voltage
+##     ARM/GPU core voltage adjust.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     -16      0.8   V
+##     -15      0.825 V
+##     -14      0.85  V
+##     -13      0.875 V
+##     -12      0.9   V
+##     -11      0.925 V
+##     -10      0.95  V
+##     -9       0.975 V
+##     -8       1.0   V
+##     -7       1.025 V
+##     -6       1.05  V
+##     -5       1.075 V
+##     -4       1.1   V
+##     -3       1.125 V
+##     -2       1.15  V
+##     -1       1.175 V
+##     0        1.2   V (Default)
+##     1        1.225 V
+##     2        1.25  V
+##     3        1.275 V
+##     4        1.3   V
+##     5        1.325 V
+##     6        1.35  V
+##     7        1.375 V (requires force_turbo=1)
+##     8        1.4   V (requires force_turbo=1)
+##
+#over_voltage=0
+
+## over_voltage_min
+##     Minimum ARM/GPU core voltage adjust (used for dynamic clocking).
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     -16      0.8   V
+##     -15      0.825 V
+##     -14      0.85  V
+##     -13      0.875 V
+##     -12      0.9   V
+##     -11      0.925 V
+##     -10      0.95  V
+##     -9       0.975 V
+##     -8       1.0   V
+##     -7       1.025 V
+##     -6       1.05  V
+##     -5       1.075 V
+##     -4       1.1   V
+##     -3       1.125 V
+##     -2       1.15  V
+##     -1       1.175 V
+##     0        1.2   V (Default)
+##     1        1.225 V
+##     2        1.25  V
+##     3        1.275 V
+##     4        1.3   V
+##     5        1.325 V
+##     6        1.35  V
+##     7        1.375 V (requires force_turbo=1)
+##     8        1.4   V (requires force_turbo=1)
+##
+#over_voltage_min=0
+
+## over_voltage_sdram
+##     Sets over_voltage_sdram_c, over_voltage_sdram_i, over_voltage_sdram_p
+##     together
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     -16      0.8   V
+##     -15      0.825 V
+##     -14      0.85  V
+##     -13      0.875 V
+##     -12      0.9   V
+##     -11      0.925 V
+##     -10      0.95  V
+##     -9       0.975 V
+##     -8       1.0   V
+##     -7       1.025 V
+##     -6       1.05  V
+##     -5       1.075 V
+##     -4       1.1   V
+##     -3       1.125 V
+##     -2       1.15  V
+##     -1       1.175 V
+##     0        1.2   V (Default)
+##     1        1.225 V
+##     2        1.25  V
+##     3        1.275 V
+##     4        1.3   V
+##     5        1.325 V
+##     6        1.35  V
+##     7        1.375 V
+##     8        1.4   V
+##
+#over_voltage_sdram=0
+
+## over_voltage_sdram_c
+##     SDRAM controller voltage adjust.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     -16      0.8   V
+##     -15      0.825 V
+##     -14      0.85  V
+##     -13      0.875 V
+##     -12      0.9   V
+##     -11      0.925 V
+##     -10      0.95  V
+##     -9       0.975 V
+##     -8       1.0   V
+##     -7       1.025 V
+##     -6       1.05  V
+##     -5       1.075 V
+##     -4       1.1   V
+##     -3       1.125 V
+##     -2       1.15  V
+##     -1       1.175 V
+##     0        1.2   V (Default)
+##     1        1.225 V
+##     2        1.25  V
+##     3        1.275 V
+##     4        1.3   V
+##     5        1.325 V
+##     6        1.35  V
+##     7        1.375 V
+##     8        1.4   V
+##
+#over_voltage_sdram_c=0
+
+## over_voltage_sdram_i
+##     SDRAM I/O voltage adjust.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     -16      0.8   V
+##     -15      0.825 V
+##     -14      0.85  V
+##     -13      0.875 V
+##     -12      0.9   V
+##     -11      0.925 V
+##     -10      0.95  V
+##     -9       0.975 V
+##     -8       1.0   V
+##     -7       1.025 V
+##     -6       1.05  V
+##     -5       1.075 V
+##     -4       1.1   V
+##     -3       1.125 V
+##     -2       1.15  V
+##     -1       1.175 V
+##     0        1.2   V (Default)
+##     1        1.225 V
+##     2        1.25  V
+##     3        1.275 V
+##     4        1.3   V
+##     5        1.325 V
+##     6        1.35  V
+##     7        1.375 V
+##     8        1.4   V
+##
+#over_voltage_sdram_i=0
+
+## over_voltage_sdram_p
+##     SDRAM phy voltage adjust.
+##
+##     Value    Description
+##     -------------------------------------------------------------------------
+##     -16      0.8   V
+##     -15      0.825 V
+##     -14      0.85  V
+##     -13      0.875 V
+##     -12      0.9   V
+##     -11      0.925 V
+##     -10      0.95  V
+##     -9       0.975 V
+##     -8       1.0   V
+##     -7       1.025 V
+##     -6       1.05  V
+##     -5       1.075 V
+##     -4       1.1   V
+##     -3       1.125 V
+##     -2       1.15  V
+##     -1       1.175 V
+##     0        1.2   V (Default)
+##     1        1.225 V
+##     2        1.25  V
+##     3        1.275 V
+##     4        1.3   V
+##     5        1.325 V
+##     6        1.35  V
+##     7        1.375 V
+##     8        1.4   V
+##
+#over_voltage_sdram_p=0
\ No newline at end of file