diff options
Diffstat (limited to 'cpu/blackfin/start.S')
| -rw-r--r-- | cpu/blackfin/start.S | 41 |
1 files changed, 17 insertions, 24 deletions
diff --git a/cpu/blackfin/start.S b/cpu/blackfin/start.S index 9975a0c..6c8def4 100644 --- a/cpu/blackfin/start.S +++ b/cpu/blackfin/start.S @@ -125,8 +125,11 @@ ENTRY(_start) */ r6 = 1 (x); - /* Relocate from wherever are (FLASH/RAM/etc...) to the - * hardcoded monitor location in the end of RAM. + /* Relocate from wherever we are (FLASH/RAM/etc...) to the hardcoded + * monitor location in the end of RAM. We know that memcpy() only + * uses registers, so it is safe to call here. Note that this only + * copies to external memory ... we do not start executing out of + * it yet (see "lower to 15" below). */ serial_early_puts("Relocate"); call _get_pc; @@ -135,27 +138,16 @@ ENTRY(_start) r2.h = .Loffset; r3.l = _start; r3.h = _start; - r1 = r2 - r3; - - r0 = r0 - r1; - - cc = r0 == r3; + r2 = r2 - r3; + r1 = r0 - r2; + cc = r1 == r3; if cc jump .Lnorelocate; - r6 = 0 (x); - p1 = r0; - - p2.l = LO(CONFIG_SYS_MONITOR_BASE); - p2.h = HI(CONFIG_SYS_MONITOR_BASE); - p3 = 0x04; - p4.l = LO(CONFIG_SYS_MONITOR_BASE + CONFIG_SYS_MONITOR_LEN); - p4.h = HI(CONFIG_SYS_MONITOR_BASE + CONFIG_SYS_MONITOR_LEN); -.Lloop1: - r1 = [p1 ++ p3]; - [p2 ++ p3] = r1; - cc=p2==p4; - if !cc jump .Lloop1; + r0 = r3; + r2.l = LO(CONFIG_SYS_MONITOR_LEN); + r2.h = HI(CONFIG_SYS_MONITOR_LEN); + call _memcpy_ASM; /* Initialize BSS section ... we know that memset() does not * use the BSS, so it is safe to call here. The bootrom LDR @@ -173,9 +165,8 @@ ENTRY(_start) .Lnorelocate: /* Setup the actual stack in external memory */ - r0.h = HI(CONFIG_STACKBASE); - r0.l = LO(CONFIG_STACKBASE); - sp = r0; + sp.h = HI(CONFIG_STACKBASE); + sp.l = LO(CONFIG_STACKBASE); fp = sp; /* Now lower ourselves from the highest interrupt level to @@ -183,7 +174,9 @@ ENTRY(_start) * setting the 15 handler to ".Lenable_nested", raising the 15 * interrupt, and then returning from the highest interrupt * level to the dummy "jump" until the interrupt controller - * services the pending 15 interrupt. + * services the pending 15 interrupt. If executing out of + * flash, these steps also changes the code flow from flash + * to external memory. */ serial_early_puts("Lower to 15"); r0 = r7; |