X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=README;h=5cf90a482a8f2056e1fc69b75aa825bffe5ae19f;hb=refs%2Fheads%2Fnext;hp=93c7ea966589984c334213fd6d84f8baa8521109;hpb=6b308494c5d5ef0cbdb76af4628b3478d0445b41;p=u-boot diff --git a/README b/README index 93c7ea9665..5cf90a482a 100644 --- a/README +++ b/README @@ -143,6 +143,7 @@ Directory Hierarchy: /nios2 Files generic to Altera NIOS2 architecture /openrisc Files generic to OpenRISC architecture /powerpc Files generic to PowerPC architecture + /riscv Files generic to RISC-V architecture /sandbox Files generic to HW-independent "sandbox" /sh Files generic to SH architecture /x86 Files generic to x86 architecture @@ -712,22 +713,6 @@ The following options need to be configured: as a convenience, when switching between booting from RAM and NFS. -- Bootcount: - CONFIG_BOOTCOUNT_LIMIT - Implements a mechanism for detecting a repeating reboot - cycle, see: - http://www.denx.de/wiki/view/DULG/UBootBootCountLimit - - CONFIG_BOOTCOUNT_ENV - If no softreset save registers are found on the hardware - "bootcount" is stored in the environment. To prevent a - saveenv on all reboots, the environment variable - "upgrade_available" is used. If "upgrade_available" is - 0, "bootcount" is always 0, if "upgrade_available" is - 1 "bootcount" is incremented in the environment. - So the Userspace Applikation must set the "upgrade_available" - and "bootcount" variable to 0, if a boot was successfully. - - Pre-Boot Commands: CONFIG_PREBOOT @@ -1202,7 +1187,7 @@ The following options need to be configured: key for the Replay Protection Memory Block partition in eMMC. - USB Device Firmware Update (DFU) class support: - CONFIG_USB_FUNCTION_DFU + CONFIG_DFU_OVER_USB This enables the USB portion of the DFU USB class CONFIG_DFU_MMC @@ -1542,14 +1527,8 @@ The following options need to be configured: You can fine tune the DHCP functionality by defining CONFIG_BOOTP_* symbols: - CONFIG_BOOTP_SUBNETMASK - CONFIG_BOOTP_GATEWAY - CONFIG_BOOTP_HOSTNAME CONFIG_BOOTP_NISDOMAIN - CONFIG_BOOTP_BOOTPATH CONFIG_BOOTP_BOOTFILESIZE - CONFIG_BOOTP_DNS - CONFIG_BOOTP_DNS2 CONFIG_BOOTP_SEND_HOSTNAME CONFIG_BOOTP_NTPSERVER CONFIG_BOOTP_TIMEOFFSET @@ -1565,15 +1544,6 @@ The following options need to be configured: to Link-local IP address configuration if the DHCP server is not available. - CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS - serverip from a DHCP server, it is possible that more - than one DNS serverip is offered to the client. - If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS - serverip will be stored in the additional environment - variable "dnsip2". The first DNS serverip is always - stored in the variable "dnsip", when CONFIG_BOOTP_DNS - is defined. - CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable to do a dynamic update of a DNS server. To do this, they need the hostname of the DHCP requester. @@ -1603,6 +1573,15 @@ The following options need to be configured: See doc/README.link-local for more information. + - MAC address from environment variables + + FDT_SEQ_MACADDR_FROM_ENV + + Fix-up device tree with MAC addresses fetched sequentially from + environment variables. This config work on assumption that + non-usable ethernet node of device-tree are either not present + or their status has been marked as "disabled". + - CDP Options: CONFIG_CDP_DEVICE_ID @@ -1991,11 +1970,6 @@ The following options need to be configured: SPI EEPROM, also an instance works with Crystal A/D and D/As on the SACSng board) - CONFIG_SH_SPI - - Enables the driver for SPI controller on SuperH. Currently - only SH7757 is supported. - CONFIG_SOFT_SPI Enables a software (bit-bang) SPI driver rather than @@ -2014,11 +1988,6 @@ The following options need to be configured: Currently supported on some MPC8xxx processors. For an example, see include/configs/mpc8349emds.h. - CONFIG_MXC_SPI - - Enables the driver for the SPI controllers on i.MX and MXC - SoCs. Currently i.MX31/35/51 are supported. - CONFIG_SYS_SPI_MXC_WAIT Timeout for waiting until spi transfer completed. default: (CONFIG_SYS_HZ/100) /* 10 ms */ @@ -2168,16 +2137,6 @@ The following options need to be configured: currently only supports clearing the memory. - Error Recovery: - CONFIG_PANIC_HANG - - Define this variable to stop the system in case of a - fatal error, so that you have to reset it manually. - This is probably NOT a good idea for an embedded - system where you want the system to reboot - automatically as fast as possible, but it may be - useful during development since you can try to debug - the conditions that lead to the situation. - CONFIG_NET_RETRY_COUNT This variable defines the number of retries for @@ -2197,10 +2156,6 @@ The following options need to be configured: #define CONFIG_NFS_TIMEOUT 10000UL - Command Interpreter: - CONFIG_AUTO_COMPLETE - - Enable auto completion of commands using TAB. - CONFIG_SYS_PROMPT_HUSH_PS2 This defines the secondary prompt string, which is @@ -2229,12 +2184,6 @@ The following options need to be configured: symbols. - Command Line Editing and History: - CONFIG_CMDLINE_EDITING - - Enable editing and History functions for interactive - command line input operations - -- Command Line PS1/PS2 support: CONFIG_CMDLINE_PS_SUPPORT Enable support for changing the command prompt string @@ -2268,20 +2217,6 @@ The following options need to be configured: the environment like the "source" command or the boot command first. - CONFIG_ENV_VARS_UBOOT_CONFIG - - Define this in order to add variables describing the - U-Boot build configuration to the default environment. - These will be named arch, cpu, board, vendor, and soc. - - Enabling this option will cause the following to be defined: - - - CONFIG_SYS_ARCH - - CONFIG_SYS_CPU - - CONFIG_SYS_BOARD - - CONFIG_SYS_VENDOR - - CONFIG_SYS_SOC - CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG Define this in order to add variables describing certain @@ -2311,18 +2246,6 @@ The following options need to be configured: CONFIG_SF_DEFAULT_MODE (see include/spi.h) CONFIG_SF_DEFAULT_SPEED in Hz - CONFIG_SYSTEMACE - - Adding this option adds support for Xilinx SystemACE - chips attached via some sort of local bus. The address - of the chip must also be defined in the - CONFIG_SYS_SYSTEMACE_BASE macro. For example: - - #define CONFIG_SYSTEMACE - #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 - - When SystemACE support is added, the "ace" device type - becomes available to the fat commands, i.e. fatls. - TFTP Fixed UDP Port: CONFIG_TFTP_PORT @@ -2344,32 +2267,6 @@ The following options need to be configured: A better solution is to properly configure the firewall, but sometimes that is not allowed. -- bootcount support: - CONFIG_BOOTCOUNT_LIMIT - - This enables the bootcounter support, see: - http://www.denx.de/wiki/DULG/UBootBootCountLimit - - CONFIG_AT91SAM9XE - enable special bootcounter support on at91sam9xe based boards. - CONFIG_SOC_DA8XX - enable special bootcounter support on da850 based boards. - CONFIG_BOOTCOUNT_RAM - enable support for the bootcounter in RAM - CONFIG_BOOTCOUNT_I2C - enable support for the bootcounter on an i2c (like RTC) device. - CONFIG_SYS_I2C_RTC_ADDR = i2c chip address - CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for - the bootcounter. - CONFIG_BOOTCOUNT_ALEN = address len - CONFIG_BOOTCOUNT_EXT - enable support for the bootcounter in EXT filesystem - CONFIG_SYS_BOOTCOUNT_ADDR = RAM address used for read - and write. - CONFIG_SYS_BOOTCOUNT_EXT_INTERFACE = interface - CONFIG_SYS_BOOTCOUNT_EXT_DEVPART = device and part - CONFIG_SYS_BOOTCOUNT_EXT_NAME = filename - - Show boot progress: CONFIG_SHOW_BOOT_PROGRESS @@ -2726,11 +2623,6 @@ FIT uImage format: CONFIG_SYS_SPL_MALLOC_SIZE The size of the malloc pool used in SPL. - CONFIG_SPL_FRAMEWORK - Enable the SPL framework under common/. This framework - supports MMC, NAND and YMODEM loading of U-Boot and NAND - NAND loading of the Linux Kernel. - CONFIG_SPL_OS_BOOT Enable booting directly to an OS from SPL. See also: doc/README.falcon @@ -3511,7 +3403,7 @@ Low Level (hardware related) configuration options: globally (CONFIG_CMD_MEMORY). - CONFIG_SKIP_LOWLEVEL_INIT - [ARM, NDS32, MIPS only] If this variable is defined, then certain + [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain low level initializations (like setting up the memory controller) are omitted and/or U-Boot does not relocate itself into RAM. @@ -3719,6 +3611,11 @@ this behavior and build U-Boot to some external directory: Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment variable. +User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by +setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. +For example to treat all compiler warnings as errors: + + make KCFLAGS=-Werror Please be aware that the Makefiles assume you are using GNU make, so for instance on NetBSD you might need to use "gmake" instead of @@ -4965,6 +4862,22 @@ On NDS32, the following registers are used: NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, or current versions of GCC may "optimize" the code too much. +On RISC-V, the following registers are used: + + x0: hard-wired zero (zero) + x1: return address (ra) + x2: stack pointer (sp) + x3: global pointer (gp) + x4: thread pointer (tp) + x5: link register (t0) + x8: frame pointer (fp) + x10-x11: arguments/return values (a0-1) + x12-x17: arguments (a2-7) + x28-31: temporaries (t3-6) + pc: program counter (pc) + + ==> U-Boot will use gp to hold a pointer to the global data + Memory Management: ------------------