| .global __cp_begin |
| .hidden __cp_begin |
| .global __cp_end |
| .hidden __cp_end |
| .global __cp_cancel |
| .hidden __cp_cancel |
| .hidden __cancel |
| .global __syscall_cp_asm |
| .hidden __syscall_cp_asm |
| |
| #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 |
| .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 |
| __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 __cp_cancel #else call cancel |
| 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 |
| __cp_end: |
| bnslr+ # return if no summary overflow. |
| #else negate result. |
| neg 3, 3 |
| blr |
| __cp_cancel: |
| b __cancel |
