diff options
Diffstat (limited to 'rbutil')
| -rw-r--r-- | rbutil/mkamsboot/dualboot/nrv2e_d8.S | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/rbutil/mkamsboot/dualboot/nrv2e_d8.S b/rbutil/mkamsboot/dualboot/nrv2e_d8.S index b112ab2936..d24fb94b2a 100644 --- a/rbutil/mkamsboot/dualboot/nrv2e_d8.S +++ b/rbutil/mkamsboot/dualboot/nrv2e_d8.S @@ -62,7 +62,10 @@ #define CHECK_BYTE /*empty*/ #endif /*}*/ -/* "mov lr,pc; bxx ..." implements conditional subroutine call */ +/* "mov lr,pc; bxx ..." implements conditional subroutine call + * + * NOTE: the lsb will not be set, so you MUST NOT use 'bx lr' to return, + * else the T bit will be cleared and processor will go in ARM state */ #define GETBIT add bits,bits; mov lr,pc; beq get1_n2e #define getnextb(reg) GETBIT; adc reg,reg @@ -123,6 +126,8 @@ get1_n2e: @ In: Carry set [from adding 0x80000000 (1<<31) to itself] CHECK_SRC add src,#1 lsl bits,#24 @ move to top byte, and set CarryOut from old bit 8 + /* NOTE: the following instruction will not work on ARMv7+, because + * it will update the T bit and return into ARM state */ mov pc,lr @ return, stay in current (THUMB) mode lit_n2e: |