Blackfin: put memory into self-refresh before/after programming clocks
When initializing the core clocks, stick external memory into self-refresh.
This gains us a few cool things:
- support suspend-to-RAM with Linux
- reprogram clocks automatically when doing "go" on u-boot.bin in RAM
- make sure settings are stable before flashing new version
- finally fully unify initialize startup code path between LDR/non-LDR
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/cpu/blackfin/start.S b/cpu/blackfin/start.S
index 6c8def4..506fea5 100644
--- a/cpu/blackfin/start.S
+++ b/cpu/blackfin/start.S
@@ -95,35 +95,63 @@
/* Save RETX so we can pass it while booting Linux */
r7 = RETX;
-#if (CONFIG_BFIN_BOOT_MODE == BFIN_BOOT_BYPASS)
- /* 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 and setup our async banks.
+ /* Figure out where we are currently executing so that we can decide
+ * how to best reprogram and relocate things. We'll pass below:
+ * R4: load address of _start
+ * R5: current (not load) address of _start
*/
- /* XXX: we should DMA this into L1, put external memory into
- * self refresh, and then jump there ...
- */
+ serial_early_puts("Find ourselves");
+
call _get_pc;
- r3 = 0x0;
- r3.h = 0x2000;
- cc = r0 < r3 (iu);
- if cc jump .Lproc_initialized;
-
- serial_early_puts("Program Clocks");
-
- call _initcode;
-
- /* Since we reprogrammed SCLK, we need to update the serial divisor */
- serial_early_set_baud
-
-.Lproc_initialized:
-#endif
+.Loffset:
+ r1.l = .Loffset;
+ r1.h = .Loffset;
+ r4.l = _start;
+ r4.h = _start;
+ r3 = r1 - r4;
+ r5 = r0 - r3;
/* Inform upper layers if we had to do the relocation ourselves.
* This allows us to detect whether we were loaded by 'go 0x1000'
- * or by the bootrom from an LDR. "r6" is "loaded_from_ldr".
+ * or by the bootrom from an LDR. "R6" is "loaded_from_ldr".
*/
r6 = 1 (x);
+ cc = r4 == r5;
+ if cc jump .Lnorelocate;
+ r6 = 0 (x);
+
+ /* 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.
+ */
+ serial_early_puts("Program Clocks");
+
+ /* if we're executing >=0x20000000, then we dont need to dma */
+ r3 = 0x0;
+ r3.h = 0x2000;
+ cc = r5 < r3 (iu);
+ if cc jump .Ldma_and_reprogram;
+ call _initcode;
+ jump .Lprogrammed;
+
+ /* we're sitting in external memory, so dma into L1 and reprogram */
+.Ldma_and_reprogram:
+ r0.l = LO(L1_INST_SRAM);
+ r0.h = HI(L1_INST_SRAM);
+ r1.l = __initcode_start;
+ r1.h = __initcode_start;
+ r2.l = __initcode_end;
+ r2.h = __initcode_end;
+ r2 = r2 - r1; /* convert r2 into length of initcode */
+ r1 = r1 - r4; /* convert r1 from load address of initcode ... */
+ r1 = r1 + r5; /* ... to current (not load) address of initcode */
+ p3 = r0;
+ call _dma_memcpy_nocache;
+ call (p3);
+
+ /* Since we reprogrammed SCLK, we need to update the serial divisor */
+.Lprogrammed:
+ serial_early_set_baud
/* Relocate from wherever we are (FLASH/RAM/etc...) to the hardcoded
* monitor location in the end of RAM. We know that memcpy() only
@@ -132,19 +160,8 @@
* it yet (see "lower to 15" below).
*/
serial_early_puts("Relocate");
- call _get_pc;
-.Loffset:
- r2.l = .Loffset;
- r2.h = .Loffset;
- r3.l = _start;
- r3.h = _start;
- r2 = r2 - r3;
- r1 = r0 - r2;
- cc = r1 == r3;
- if cc jump .Lnorelocate;
- r6 = 0 (x);
-
- r0 = r3;
+ r0 = r4;
+ r1 = r5;
r2.l = LO(CONFIG_SYS_MONITOR_LEN);
r2.h = HI(CONFIG_SYS_MONITOR_LEN);
call _memcpy_ASM;