Hi Stephen,
On 19 December 2017 at 18:30, Stephen Warren swarren@wwwdotorg.org wrote:
From: Stephen Warren swarren@nvidia.com
U-Boot typically uses a hard-coded value for the stack pointer before relocation. Implement option SYS_INIT_SP_BSS_OFFSET to instead calculate the initial SP at run-time. This is useful to avoid hard-coding addresses into U-Boot, so that can be loaded and executed at arbitrary addresses and thus avoid using arbitrary addresses at runtime. This option's value is the offset added to &_bss_start in order to calculate the stack pointer. This offset should be large enough so that the early malloc region, global data (gd), and early stack usage do not overlap any appended DTB.
I don't see why this is an offset from bss_start - shouldn't it be bss_end?
Also this seems error-prone since we don't know how large the DTB is. Can we improve this, e.g. by:
- using binman to provide the stack start value or offset - checking the DTB size and automatically using the address immediately after it finishes (again I suppose binman could provide that)
Regards, Simon