diff options
Diffstat (limited to 'arch/blackfin/cpu')
| -rw-r--r-- | arch/blackfin/cpu/start.S | 45 |
1 files changed, 33 insertions, 12 deletions
diff --git a/arch/blackfin/cpu/start.S b/arch/blackfin/cpu/start.S index 7a3abba..15ecb1e 100644 --- a/arch/blackfin/cpu/start.S +++ b/arch/blackfin/cpu/start.S @@ -52,6 +52,19 @@ ENTRY(_start) sp.l = LO(L1_SRAM_SCRATCH_END - 20); sp.h = HI(L1_SRAM_SCRATCH_END - 20); + /* Optimization register tricks: keep a base value in the + * reserved P registers so we use the load/store with an + * offset syntax. R0 = [P5 + <constant>]; + * P4 - system MMR base + * P5 - core MMR base + */ +#ifdef CONFIG_HW_WATCHDOG + p4.l = 0; + p4.h = HI(SYSMMR_BASE); +#endif + p5.l = 0; + p5.h = HI(COREMMR_BASE); + #ifdef CONFIG_HW_WATCHDOG # ifndef CONFIG_HW_WATCHDOG_TIMEOUT_START # define CONFIG_HW_WATCHDOG_TIMEOUT_START 5000 @@ -60,13 +73,11 @@ ENTRY(_start) * That should be long enough to bootstrap ourselves up and * then the common u-boot code can take over. */ - P0.L = LO(WDOG_CNT); - P0.H = HI(WDOG_CNT); - R0.L = 0; - R0.H = HI(MSEC_TO_SCLK(CONFIG_HW_WATCHDOG_TIMEOUT_START)); - [P0] = R0; + r0 = 0; + r0.h = HI(MSEC_TO_SCLK(CONFIG_HW_WATCHDOG_TIMEOUT_START)); + [p4 + (WDOG_CNT - SYSMMR_BASE)] = r0; /* fire up the watchdog - R0.L above needs to be 0x0000 */ - W[P0 + (WDOG_CTL - WDOG_CNT)] = R0; + W[p4 + (WDOG_CTL - SYSMMR_BASE)] = r0; #endif /* Turn on the serial for debugging the init process */ @@ -121,6 +132,18 @@ ENTRY(_start) if cc jump .Lnorelocate; r6 = 0 (x); + /* Turn off caches as they require CPLBs and a CPLB miss requires + * a software exception handler to process it. But we're about to + * clobber any previous executing software (like U-Boot that just + * launched a new U-Boot via 'go'), so any handler state will be + * unreliable after the memcpy below. + */ + serial_early_puts("Kill Caches"); + r0 = 0; + [p5 + (IMEM_CONTROL - COREMMR_BASE)] = r0; + [p5 + (DMEM_CONTROL - COREMMR_BASE)] = r0; + ssync; + /* In bypass mode, we don't have an LDR with an init block * so we need to explicitly call it ourselves. This will * reprogram our clocks, memory, and setup our async banks. @@ -204,17 +227,15 @@ ENTRY(_start) serial_early_puts("Lower to 15"); r0 = r7; r1 = r6; - p0.l = LO(EVT15); - p0.h = HI(EVT15); p1.l = .Lenable_nested; p1.h = .Lenable_nested; - [p0] = p1; + [p5 + (EVT15 - COREMMR_BASE)] = p1; r7 = EVT_IVG15 (z); sti r7; raise 15; - p4.l = .LWAIT_HERE; - p4.h = .LWAIT_HERE; - reti = p4; + p3.l = .LWAIT_HERE; + p3.h = .LWAIT_HERE; + reti = p3; rti; /* Enable nested interrupts before continuing with cpu init */ |