diff options
| author | Rafaël Carré <rafael.carre@gmail.com> | 2010-06-01 16:53:26 +0000 |
|---|---|---|
| committer | Rafaël Carré <rafael.carre@gmail.com> | 2010-06-01 16:53:26 +0000 |
| commit | 27d529e18691b4a3a32669fe631ce96ff717872f (patch) | |
| tree | 6937a3dc8a3e27455e4c2f7cc6ff4e850f0b0a9f /rbutil | |
| parent | 0a054b288b4ac71f384a18f7c9f8835863fe3751 (diff) | |
mkamsboot / nrv2e_d8.S thubm decompressor : comment the use of mov pc, lr
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26449 a1c6a512-1295-4272-9138-f99709370657
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: |