diff options
Diffstat (limited to 'bsps/bfin/bf537Stamp/start/start.S')
| -rw-r--r-- | bsps/bfin/bf537Stamp/start/start.S | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/bsps/bfin/bf537Stamp/start/start.S b/bsps/bfin/bf537Stamp/start/start.S new file mode 100644 index 0000000000..a835a48764 --- /dev/null +++ b/bsps/bfin/bf537Stamp/start/start.S @@ -0,0 +1,115 @@ +#include <libcpu/bf537.h> +#include <libcpu/sicRegs.h> +#include <libcpu/cecRegs.h> +#include <libcpu/dmaRegs.h> +#include <libcpu/coreTimerRegs.h> + +#ifndef LO +#define LO(con32) ((con32) & 0xFFFF) +#endif +#ifndef HI +#define HI(con32) (((con32) >> 16) & 0xFFFF) +#endif + + .section .start + .align 4 + + .global __start +__start: + cli r0; + + /* setup an initial stack */ + sp.h = 0xFFB0; + sp.l = 0x0F00; + + /* disable timer interrupts */ + p0.h = HI(TCNTL); + p0.l = LO(TCNTL); + r0 = 0; + [p0] = r0; + + /* disable all interrupts routed through sic */ + p0.h = HI(SIC_IMASK); + p0.l = LO(SIC_IMASK); + [p0] = r0; + + /* clear any pending interrupts */ + p0.h = HI(CEC_ILAT); + p0.l = LO(CEC_ILAT); + r0 = 0xffff (z); + [p0] = r0; + + /* disable all dma channels */ + p0.h = HI(DMA0_BASE_ADDRESS + DMA_CONFIG_OFFSET); + p0.l = LO(DMA0_BASE_ADDRESS + DMA_CONFIG_OFFSET); + p1 = DMA_PITCH; + p2 = DMA_CHANNELS; + r0 = ~DMA_CONFIG_DMAEN; + lsetup(loop1,loop2) lc0 = p2; +loop1: r1 = w[p0]; + r1 = r0 & r1; +loop2: w[p0 ++ p1] = r1.l; + + /* this is so we can stay in supervisor mode and still be able to + accept interrupts later. */ + p0.h = start; + p0.l = start; + p1.h = HI(CEC_EVT15); + p1.l = LO(CEC_EVT15); + + [p1] = p0; + + r0 = 0x8000 (z); + sti r0; + + raise 15; + + p0.h = wait; + p0.l = wait; + + reti = p0; + rti; + + /* wait for event 15 */ +wait: + jump wait; + +start: + [--sp] = reti; /* allow us to process interrupts later */ + + /* mask interrupts for now */ + cli r0; + + p0.h = _bss_start; + p0.l = _bss_start; + p1.h = _end; + p1.l = _end; + r0 = p0; + r1 = p1; + r1 = r1 - r0; + p1 = r1; + r0 = 0; + + /* Set _bss_start until _end to zero */ + lsetup(loop3,loop4) lc0 = p1; +loop3: b[p0] = r0; +loop4: p0 +=1; + + l0 = 0; + l1 = 0; + l2 = 0; + l3 = 0; + sp += -12; + /* r0 == const char *cmdline (currently null) */ + p0.h = _boot_card; + p0.l = _boot_card; + call (p0); + sp += 12; + + .global _bsp_reset +_bsp_reset: + HLT + p0.h = _exit; + p0.l = _exit; + jump (p0); + |