Bug 42557
| Summary: | PPC HAL needs cleanup to adhere to ABI/EABIs | ||
|---|---|---|---|
| Product: | [Retired] eCos | Reporter: | Jesper Skov <jskov> |
| Component: | HAL | Assignee: | ecc-bugs-int |
| Status: | CLOSED WONTFIX | QA Contact: | ecc-bugs-int |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | CVS | ||
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | i386 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2003-06-20 16:00:33 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
This bug has moved to http://bugs.ecos.sourceware.org/show_bug.cgi?id=42557 |
Paul> Main question I have for you guys is to understand in the case Paul> of the PPC what the extra effort would be if we had to use the Paul> PPC Linux as apposed to EABI compiler? >> I think we concluded last week this would make no difference. We >> already use a PPC Linux compiler for eCos PPC boards in the farm >> right now, apparently. >> >> But we'd want to check the ABI differences and make sure. If there >> are any changes, the code could be fixed in a matter of minutes. Paul> Nick seemed to have an about turn and think this could Paul> potentially be pretty far reaching - especially the MIPS arch - Paul> v.different ABI due to PIC/PID, etc? Paul> Pls check PPC Linux compiler usage... I've looked at the PPC EABI which is an extension of the SVR4 ABI. There are no changes to use of registers in calls. In SVR4 the stack pointer must always be 16-byte aligned, while in the EABI it only needs to be 8-byte aligned. I believe we may actually leave it only 4-byte aligned in some situations, so that would need fixing (and according to the ABI in effect). There are similar alignment differences for aggregate and long data types, so we (I) should double check the linker script alignment statements. Finally, we don't initialize GPR13 as required by both ABIs, and I suspect the linker script also botches on the definition of the symbol used for initializing GPR2 which is a requirement in the EABI. Again, something that needs to be cleaned up and made dynamic based on the ABI in effect. I'm opening a bug on these issues. Jesper