This patch series marks a considerably significant milestone in the x86
port of U-Boot - Running the initial init sequence from Flash using the
CPU on-die cache as a temporary stack.
Prior to this patch series, the low-level assembler code running in Flash
was responsible for initialising SDRAM and getting the C environment (the
stack) set up. The C code would then simply copy the U-Boot image to RAM,
do some relocation adjustments and jump into the in-RAM copy - only then
would the init sequence run.
Thank to the assistance of Juergen Beisert (who had done a Cache-As-RAM
implementation for the sc520 quite some time ago), the x86 boot sequence
is more 'standard':
- Initialise Cache-As-RAM (CAR)
- Setup a restricted 'C' environment
- Setup initial global data in CAR
- Run init sequence from Flash
- Copy global data to a newly malloc'd block
- Jump to RAM
This patch does have three 'negative' impacts:
- Boot time is slightly slower due to running the init sequence from
Flash rather than SDRAM
- The image is no longer position independent - If you want to create
a warm-boot u-boot image, you need to link it to a different address
- You can no longer do a warm-boot to a new u-boot image from SDARM
(SDRAM is always re-initialised during the init sequence)
Regards,
Graeme
Changes since RFC:
- Ran checkpatch.pl and fixed (most) errors and warnings (a few long
lines remain for readability and sc520_enable_ecc() in
arch\i386\cpu\sc520 contains raw asm which is #ifdef'd out - This is
ECC initialisation copied from the original asm file which is retained
in case someone with ECC capable hardware (which I do not have) would
care to implement properly
- Merged some patches that logically belonged together
- Added a code tidy-up for eNET
- #defined all 'magic numbers' in the eNET configuration file
- rebased to u-boot/master
Graeme Russ (32):
x86: Fix definition of global_data struct for asm-offsets.c
x86: Align config.mk and linker scripts with other arches
eNET: Create distinct board configurations
x86: Parametize values used in linker script
sc520: Sort Makefile
x86: Fix mangled umlauts
x86: Add stack dump to register dump
x86: Move Global Descriptor Table defines to processor.h
x86: Add processor flags header from linux
x86: Call early_board_init when warm booting
x86: Make cpu init functions weak
sc520: Define MMCR address in include file
sc520: Move board specific settings to board init function
sc520: Remove printf calls from cpu_init_f
eNET: Fix eNET Interrupt Setup for Linux
eNET: Add RTC support to eNET
eNET: Define MMCR values in config.h
eNET: Rearrange PAR assignments
eNET: General code cleanup
x86: Move initial gd to fixed location
x86: Use Cache-As-RAM for initial stack
sc520: Move RAM sizing code from asm to C
x86: Defer setup of final stack
x86: Move call to dram_init_f into board_init_f
x86: Move test for cold boot into init functions
x86: Move console initialisation into board_init_f
x86: Fix incorrect usage of relocation offset
x86: Split board_init_f() into init_fnc_t compatible functions
x86: Rearrange function calls in board_init_f
x86: Convert board_init_f to use an init_sequence
sc520: Release CAR and enable caching
eNET: Move initial Global Data into CAR
arch/i386/config.mk | 14 +-
arch/i386/cpu/config.mk | 10 +-
arch/i386/cpu/cpu.c | 35 +-
arch/i386/cpu/interrupts.c | 19 +-
arch/i386/cpu/sc520/Makefile | 5 +-
arch/i386/cpu/sc520/sc520.c | 148 +-------
arch/i386/cpu/sc520/sc520_asm.S | 615 ----------------------------
arch/i386/cpu/sc520/sc520_car.S | 94 +++++
arch/i386/cpu/sc520/sc520_sdram.c | 532 ++++++++++++++++++++++++
arch/i386/cpu/start.S | 107 +++---
arch/i386/cpu/start16.S | 5 +-
arch/i386/cpu/u-boot.lds | 96 +++++
arch/i386/include/asm/global_data.h | 21 +-
arch/i386/include/asm/ic/sc520.h | 93 ++++-
arch/i386/include/asm/processor-flags.h | 100 +++++
arch/i386/include/asm/processor.h | 9 +-
arch/i386/include/asm/u-boot-i386.h | 3 +
arch/i386/lib/board.c | 144 ++++---
arch/i386/lib/realmode.c | 8 +-
board/eNET/config.mk | 6 +-
board/eNET/eNET.c | 192 +++++----
board/eNET/eNET_start.S | 7 -
board/eNET/eNET_start16.S | 15 +-
board/eNET/u-boot.lds | 104 -----
boards.cfg | 3 +-
drivers/rtc/mc146818.c | 6 +
include/configs/eNET.h | 678 +++++++++++++++++++++++--------
27 files changed, 1786 insertions(+), 1283 deletions(-)
delete mode 100644 arch/i386/cpu/sc520/sc520_asm.S
create mode 100644 arch/i386/cpu/sc520/sc520_car.S
create mode 100644 arch/i386/cpu/sc520/sc520_sdram.c
create mode 100644 arch/i386/cpu/u-boot.lds
create mode 100644 arch/i386/include/asm/processor-flags.h
delete mode 100644 board/eNET/u-boot.lds
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