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/**
* Original Filename: os.c
*/
#include "ultra64.h"
#include "audio.h"
void Audio_InvalDCache(void* buf, s32 size) {
OSIntMask prevMask = osSetIntMask(OS_IM_NONE);
osInvalDCache(buf, size);
osSetIntMask(prevMask);
}
void Audio_WritebackDCache(void* buf, s32 size) {
OSIntMask prevMask = osSetIntMask(OS_IM_NONE);
osWritebackDCache(buf, size);
osSetIntMask(prevMask);
}
/**
* Submits an audio buffer to be consumed by the Audio DAC. The audio interface can queue a second DMA while another
* is in progress and automatically begin the next one as soon as the current DMA completes. If there is already a
* second DMA queued (DMA is full), -1 is returned to indicate the buffer could not be submitted.
*
* Note that this is not the same as the original libultra osAiSetNextBuffer, see comments in the function.
*
* @param buf Next audio buffer. Must be an 8-byte aligned KSEG0 (0x80XXXXXX) address.
* @param size Length of next audio buffer in bytes, maximum size 0x40000 bytes / 256 KiB. Should be a multiple of 8.
* @return 0 if the DMA was enqueued successfully, -1 if the DMA could not yet be queued.
*/
s32 osAiSetNextBuffer(void* buf, u32 size) {
static u8 hdwrBugFlag = false;
u32 bufAdjusted = (u32)buf;
s32 status;
// Workaround for a hardware bug. If the end of the previous buffer was on an 0x2000 byte boundary, adjust the
// start of the next buffer.
if (hdwrBugFlag) {
bufAdjusted -= 0x2000;
}
// Current buffer ends on an 0x2000 byte boundary, set flag to account for this in next buffer.
if ((((u32)buf + size) & 0x1FFF) == 0) {
hdwrBugFlag = true;
} else {
hdwrBugFlag = false;
}
// Originally a call to __osAiDeviceBusy
//! @bug The original __osAiDeviceBusy call was above the hardware bug workaround to ensure that it was only
//! performed when a transfer was guaranteed to start. If this condition passes and this function returns without
//! submitting a buffer for DMA, the code above will lose track of when to apply the workaround.
status = IO_READ(AI_STATUS_REG);
if (status & AI_STATUS_FIFO_FULL) {
return -1;
}
// OS_K0_TO_PHYSICAL replaces osVirtualToPhysical, this replacement assumes that only KSEG0 addresses are given.
IO_WRITE(AI_DRAM_ADDR_REG, OS_K0_TO_PHYSICAL(bufAdjusted));
IO_WRITE(AI_LEN_REG, size);
return 0;
}
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