There has been talk on and off of a pre-relocation malloc() implementation. Driver model needs this so that it can work before relocation.
A previous implementation was sent in a v1 series. This implementation works by allocating space on the stack. The benefit is that boards do not need to specify the address of the malloc() area, only the size. The down-side is that due to the way board_init_f() is called, architecture-specific code needs to be used to allocate the space. No clever algorithms are used to allocate space, free() is a nop and realloc() is not supported. This fits well with the desire to avoid wasting space on bucket tables and the hassle of supporting BSS data before relocation. We don't expect 'churn' in the pre-relocation case - we just want to allocate small amounts of memory temporarily. After relocation a new malloc() pool is created and the old one is lost, although pointers into it will survive the immediate process of relocation. Implementations are provided for sandbox and arm (32-bit only). A related change is made to the early init for each arch to make this work. Changes in v3: - Fix assembler code comment in crt0.S to say GD, not BSS - Ensure that aarch64 stays as it was - Add newline after clr_gd label - Remove redundant mov r0, #0 - Rebase on earlier patch - Put the two CONFIG changes together in sandbox.h Changes in v2: - Tidy up commit message typo Simon Glass (9): Remove form-feeds from dlmalloc.c arm: Set up global data before board_init_f() sandbox: Set up global data before board_init_f() Add a simple malloc() implementation for pre-relocation arm: Support pre-relocation malloc() exynos: Enable pre-relocation malloc() sandbox: Support pre-relocation malloc() sandbox: config: Enable pre-relocation malloc() sandbox: Always enable malloc debug README | 16 ++++++++ arch/arm/include/asm/config.h | 2 + arch/arm/lib/crt0.S | 12 ++++++ arch/sandbox/cpu/start.c | 8 ++++ arch/sandbox/include/asm/config.h | 1 - common/board_f.c | 12 ++++++ common/board_r.c | 4 ++ common/dlmalloc.c | 85 ++++++++++++++++++++++++++++----------- include/asm-generic/global_data.h | 5 +++ include/configs/exynos5-dt.h | 4 +- include/configs/sandbox.h | 4 +- lib/asm-offsets.c | 3 ++ 12 files changed, 129 insertions(+), 27 deletions(-) -- 2.0.0.526.g5318336 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
