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| author | John-Mark Bell <jmb@netsurf-browser.org> | 2022-06-02 02:01:04 +0100 |
|---|---|---|
| committer | John-Mark Bell <jmb@netsurf-browser.org> | 2022-11-01 20:24:06 +0000 |
| commit | 5614c157989873efdb53cb5633ee9eb461ec814c (patch) | |
| tree | 2a62035f82926b6083f2f74435ace54f44550d5d | |
| parent | 702073888df04286767540c3159c2c6e385a761d (diff) | |
| download | toolchains-5614c157989873efdb53cb5633ee9eb461ec814c.tar.gz toolchains-5614c157989873efdb53cb5633ee9eb461ec814c.tar.bz2 | |
Fix initial stack allocation for EABI and soft FP.
In this case, there are no VFP registers to reserve space for at
the top of the application stack. Thus, the stack pointer points
at the top of the stack when we ask ARMEABISupport to give us the
stack handle. Unfortunately, despite the top address being given
to us by ARMEABISupport in the first place, it does not consider
the top of the stack to be part of the stack's storage space and
thus we fail to obtain our stack handle and the application aborts.
Work around this by discarding the top N bytes of the stack when
EABI and soft FP are active. The resulting stack pointer will be
aligned to a multiple of 8 bytes in the usual way for AAPCS.
Additionally, resolve another stack imbalance in an error path
that was spotted while working through this.
| -rw-r--r-- | arm-riscos-gnueabihf/recipes/patches/gccsdk/unixlib-initial-sp.p | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arm-riscos-gnueabihf/recipes/patches/gccsdk/unixlib-initial-sp.p b/arm-riscos-gnueabihf/recipes/patches/gccsdk/unixlib-initial-sp.p new file mode 100644 index 0000000..f3309c2 --- /dev/null +++ b/arm-riscos-gnueabihf/recipes/patches/gccsdk/unixlib-initial-sp.p @@ -0,0 +1,31 @@ +Index: libunixlib/sys/_syslib.s +=================================================================== +--- libunixlib/sys/_syslib.s (revision 7698) ++++ libunixlib/sys/_syslib.s (working copy) +@@ -396,8 +396,9 @@ + SWI XOS_ReadVarVal @ Read value of progname$HeapMax + BVS t08 + TEQ v1, #1 @ Should be a number variable +- LDREQ v2, [sp], #4 ++ LDREQ v2, [sp] + MOVEQ v2, v2, LSL#20 @ Convert MB into bytes ++ ADD sp, sp, #4 + + @ v2 = size of DA area + t08: +@@ -512,7 +513,15 @@ + MOVCC a1, #ERR_NO_FPE + BCC __exit_with_error_num + #endif ++#else ++#ifdef __ARM_EABI__ ++ @ EABI with software FP. Burn the top of the stack to appease ++ @ ARMEABISupport (which does not consider the stack top address ++ @ as part of the stack). ++ SUB sp, sp, #4 ++ BIC sp, sp, #7 @ AAPCS wants 8 byte alignment + #endif ++#endif + + @ We need to create this now so that we have its address to give to + @ the callback handler, but we can initialise it later. |