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
This commit is contained in:
Rafaël Carré 2010-06-01 16:53:26 +00:00
parent 0a054b288b
commit 27d529e186

View file

@ -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: