Hi Tom,
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+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
CONFIG_SKIP_LOWLEVEL_INIT is not used in the other patches. Why is this needed ? board/samsung/samsung/smdk6400 has a lowlevel_init.o function. It is confusing why this function is being if-def and not the real lowlevel_init..
Will remove.
+#ifdef CONFIG_ENABLE_MMU
This logic is may not be quite correct From include/configs/smdk6400.h #if !defined(CONFIG_NAND_SPL) && (TEXT_BASE >= 0xc0000000) #define CONFIG_ENABLE_MMU #endif Please check
Thanks. This logic was broken.
I have reworked this logic as follows, and removed the ifdef:
- adr r1, mmu_disable_phys - /* We presume we're within the first 1024 bytes */ - and r1, r1, #0x3fc - ldr r2, _TEXT_PHY_BASE - ldr r3, =0xfff00000 - and r2, r2, r3 - orr r2, r2, r1 + adr r2, mmu_disable_phys + sub r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - TEXT_BASE)
The earlier implementation was masking out too many bits in trying to convert the jump address from virtual to physical. Any comments on this change?
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/* Prepare to disable the MMU */ adr r1, mmu_disable_phys /* We presume we're within the first 1024 bytes */ @@ -187,20 +189,60 @@ mmu_disable: nop nop mov pc, r2 +mmu_disable_phys: +#else
- mcr p15, 0, r0, c1, c0, 0
Are the noop's above needed here?
I think the original author's intent was to entirely occupy one cache line. I don't know enough about the s3c64xx architecture to comment.
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mcr p15,0,r0,c15,c2,4 @ 256M (0x70000000 - 0x7fffffff)
This comment '@ 256 .. ' is no longer valid.
Thanks. Will fix.
[...]
- /* move to reserved a couple spots for abort stack */
- /* reserved a couple spots for abort stack */
The old comment makes more sense. Revert this.
Thanks. Will fix.
[...]
+#define CONFIG_SKIP_RELOCATE_UBOOT
There is logic later in this file to undef this value. This is likely an error. If it isn't, add a comment.
I have removed the subsequent undef and verified that the generated disassembly of start.S remains the same (with the exception of the address computation change above) for both usb and non-usb smdk6400 builds.
Thanks Cyril.