u-boot.git/arch/arc, branch v2015.04-rc2

arc: introduce U-Boot port for ARCv2 ISA

2015-02-13T06:17:51Z

ARC HS and ARC EM are new cores based on ARCv2 ISA which is binary incompatible with ISAv1 (AKA ARCompact). Significant difference between ISAv2 and v1 is implementation of interrupt vector table. In v1 it is implemented in the same way as on many other architectures - as a special location where user may put whether code executed in place (if machine word of space is enough) or jump to a full-scale interrupt handler. In v2 interrupt table is just an array of adresses of real interrupt handlers. That requires a separate section for IVT that is not encoded as code by assembler. This change adds support for following cores: * ARC EM6 (simple 32-bit microcontroller without MMU) * ARC HS36 (advanced 32-bit microcontroller without MMU) * ARC HS38 (advanced 32-bit microcontroller with MMU) As a part of ARC HS38 new version of MMU (v4) was introduced. Also this change adds AXS131 board which is the same DW ARC SDP base board but with ARC HS38 CPU tile. Signed-off-by: Alexey Brodkin

arc: build libgcc in U-Boot

2015-02-09T13:41:20Z

This way we may have very limited set of functions implemented so we save some space. Also it allows us to build U-Boot for any ARC core with the same one toolchain because we don't rely on pre-built libgcc. For example: * we may use little-endian toolchain but build U-Boot for ether endianess * we may use non-multilibbed uClibc toolchain but build U-Boot for whatever ARC CPU flavour that current GCC supports Private libgcc built from generic C implementation contributes only 144 bytes to .text section so we don't see significant degradation of size: --->8--- $ arc-linux-size u-boot.libgcc-prebuilt text data bss dec hex filename 222217 24912 214820 461949 70c7d u-boot.libgcc-prebuilt $ arc-linux-size u-boot.libgcc-private text data bss dec hex filename 222361 24912 214820 462093 70d0d u-boot.libgcc-private --->8--- Also I don't notice visible performance degradation compared to pre-built libgcc (where at least "*div*" functions are had-written in assembly) on typical operations of downloading 10Mb uImage over TFTP and bootm. Signed-off-by: Alexey Brodkin

arc: move CPU flags selection to the main "config.mk"

2015-02-09T13:41:20Z

As a preparation to ARCv2 port submission we're moving CPU slection flags to a common location. Also it will allow us to have more flexible CPU specification, not only ISA version but CPU family as well checking CONFIG_ARC_CPU_xxx. Signed-off-by: Alexey Brodkin

arc: hard-code CONFIG_ARCH_EARLY_INIT_R in asm/config.h

2015-02-09T13:41:20Z

Common arch_early_init_r() is used in "arc/lib/cpu.c" for all ARC boards so there's no sense in separate per-board definitions. Signed-off-by: Alexey Brodkin

arc: hard-code CONFIG_SYS_GENERIC_BOARD into asm/config.h

2015-02-09T13:41:20Z

There're no other options for ARC except "generic board" so ther's no point to define CONFIG_SYS_GENERIC_BOARD per board. We now have it set fo all ARC boards. Signed-off-by: Alexey Brodkin

arc: add selection of endianess in Kconfig

2015-02-09T13:41:20Z

This change allows to keep board description clean and minimalistic. This is especially helpful if one board may house different CPUs with different features. It is applicable to both FPGA-based boards or those that have CPUs mounted on interchnagable daughter-boards. Signed-off-by: Alexey Brodkin

arc: select cache settings via menuconfig

2015-02-09T13:41:20Z

arc: define and use PTAG AUX regs for MMUv3 only

2015-02-09T13:41:20Z

DC_PTAG and IC_PTAG registers only exist in MMUv3. Signed-off-by: Alexey Brodkin

arc: add more flavours of ARC700 series CPU

2015-02-09T13:41:20Z

Now we may select a particular version of ARC700: * ARC750D or * ARC770D It allows more flexible (or more fine tuned) configuration of U-Boot. Before that change we relied on minimal configuration but now we may use specific features of each CPU. Moreover allows us to escape manual selection of options that exist in both CPUs but may have say different version like MMUv2 in ARC750D vs MMUv3 in ARC770D. Signed-off-by: Alexey Brodkin

arc: memcmp - fix zero-delay loop utilization

2015-02-09T13:41:20Z

It's prohibited to put branch instruction in the very end of zero-delay loop. On execution this causes "Illegal instruction" exception. Signed-off-by: Alexey Brodkin Signed-off-by: Igor Guryanov