diff options
Diffstat (limited to 'src/thread/powerpc/syscall_cp.s')
| -rw-r--r-- | src/thread/powerpc/syscall_cp.s | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/src/thread/powerpc/syscall_cp.s b/src/thread/powerpc/syscall_cp.s new file mode 100644 index 00000000..2c97ca04 --- /dev/null +++ b/src/thread/powerpc/syscall_cp.s @@ -0,0 +1,51 @@ +#r0: volatile. may be modified during linkage. +#r1: stack frame: 16 byte alignment. +#r2: tls/thread pointer on pp32 +#r3,r4: return values, first args +#r5-r10: args +#r11-r12: volatile. may be modified during linkage +#r13: "small data area" pointer +#r14 - r30: local vars +#r31: local or environment pointer + +#r1, r14-31: belong to the caller, must be saved and restored +#r0, r3-r12, ctr, xer: volatile, not preserved +#r0,r11,r12: may be altered by cross-module call, +#"a func cannot depend on that these regs have the values placed by the caller" + +#the fields CR2,CR2,CR4 of the cond reg must be preserved +#LR (link reg) shall contain the funcs return address + .text + .global __syscall_cp_asm + .type __syscall_cp_asm,%function +__syscall_cp_asm: + # at enter: r3 = pointer to self->cancel, r4: syscall no, r5: first arg, r6: 2nd, r7: 3rd, r8: 4th, r9: 5th, r10: 6th + .global __cp_begin +__cp_begin: + # r3 holds first argument, its a pointer to self->cancel. + # we must compare the dereferenced value with 0 and jump to __cancel if its not + + lwz 0, 0(3) #deref pointer into r0 + + cmpwi cr7, 0, 0 #compare r0 with 0, store result in cr7. + beq+ cr7, 1f #jump to label 1 if r0 was 0 + + b __cancel #else call cancel + # (the return address is not needed, since __cancel never returns) +1: + #ok, the cancel flag was not set + # syscall: number goes to r0, the rest 3-8 + mr 0, 4 # put the system call number into r0 + mr 3, 5 # Shift the arguments: arg1 + mr 4, 6 # arg2 + mr 5, 7 # arg3 + mr 6, 8 # arg4 + mr 7, 9 # arg5 + mr 8, 10 # arg6 + sc + .global __cp_end +__cp_end: + bnslr+ # return if no summary overflow. + #else negate result. + neg 3, 3 + blr |