diff options
Diffstat (limited to 'firmware')
| -rw-r--r-- | firmware/target/arm/rk27xx/crt0.S | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/firmware/target/arm/rk27xx/crt0.S b/firmware/target/arm/rk27xx/crt0.S index 032c637458..4ddae01c53 100644 --- a/firmware/target/arm/rk27xx/crt0.S +++ b/firmware/target/arm/rk27xx/crt0.S @@ -47,14 +47,20 @@ newstart2: mov r0, #0x18000000 add r0, r0, #0x1c000 - /* setup ARM core freq = 200MHz */ - /* AHB bus freq (HCLK) = 100MHz */ - /* APB bus freq (PCLK) = 50MHz */ + /* setup ARM core freq = 200MHz + * AHB bus freq (HCLK) = 100MHz + * APB bus freq (PCLK) = 50MHz + * Note: it seems there is no way to run AHB bus at ARM freq + * bit2 in DIVCON1 must have different meaning to what datasheet + * states. It influences SDRAM read speed but does not change + * APB freq + */ ldr r1, [r0,#0x14] /* SCU_DIVCON1 */ - orr r1, #9 /* ARM slow mode, HCLK:PCLK = 2:1 */ + bic r1, r1, #0x1f + orr r1, r1, #9 /* ((1<<3)|(1<<0)) ARM slow mode, HCLK:PCLK = 2:1 */ str r1, [r0,#0x14] - ldr r1,=0x01970c70 /* (1<<24) | (1<<23) | (23<<16) | (199<<4) */ + ldr r1,=0x1850310 /* ((1<<24)|(1<<23)|(5<<16)|(49<<4)) */ str r1, [r0,#0x08] ldr r2,=0x40000 @@ -62,11 +68,11 @@ newstart2: ldr r1, [r0,#0x2c] /* SCU_STATUS */ tst r1, #1 /* ARM pll lock */ bne 1f - subs r2, #1 + subs r2, r2, #1 bne 1b 1: ldr r1, [r0,#0x14] /* SCU_DIVCON1 */ - bic r1, #5 /* leave ARM slow mode, ARMclk:HCLK = 2:1 */ + bic r1, #1 /* leave ARM slow mode */ str r1, [r0,#0x14] #if defined(BOOTLOADER) @@ -75,7 +81,6 @@ newstart2: str r1, [r0, #4] #endif -#if 0 /* setup caches */ ldr r0, =0xefff0000 /* cache controler base address */ ldrh r1, [r0] @@ -110,7 +115,6 @@ newstart2: ldr r1, [r0] orr r1, r1, #0x80000000 str r1, [r0] /* global cache enable */ -#endif /* Copy interrupt vectors to iram */ ldr r2, =_intvectstart |