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Improve the comment readability.

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Signed-off-by: Ricky Zhang <rickyzhang@gmail.com>
This commit is contained in:
Ricky Zhang 2020-07-15 21:14:20 -04:00
parent 03ebc5375b
commit 5f1b41eb42
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GPG Key ID: 681AFAEF6CDEDB4C
1 changed files with 30 additions and 15 deletions
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45
BasiliskII/src/rom_patches.cpp
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@ -1010,25 +1010,35 @@ static bool patch_rom_classic(void)
*wp = htons(0x67f4); // beq 0x402be2 *wp = htons(0x67f4); // beq 0x402be2
// Patch guest screen for an arbitary resolution // Patch the guest screen for an arbitary resolution
// We are going to steal the ROM space that runs RAM test // We are going to steal the abandoned ROM space that runs RAM test
uint32 patchCodeBaseMac; // a stateful variable to keep track of the stolen location of the patched code in guest memory. // for patching ROM.
uint16* patchwp; // a stateful word pointer pointing to the patch code in host memory.
uint32* patchlp; // a stateful long pointer pointing to the patch code in host memory.
uint32* lp; // a statless long pointer // a stateful variable to keep track of the stolen location
// of the patched code in guest memory.
uint32 patchCodeBaseMac;
// a stateful word pointer pointing to the patch code in host memory.
uint16* patchwp;
// a stateful long pointer pointing to the patch code in host memory.
uint32* patchlp;
// a statless long pointer
uint32* lp;
wp = (uint16 *)(ROMBaseHost + 0x5ca); // start to patch P_mInitVideoGlobal route // start to patch P_mInitVideoGlobal route
wp = (uint16 *)(ROMBaseHost + 0x5ca);
*wp++ = htons(0x4eb9); /* JSR */ *wp++ = htons(0x4eb9); /* JSR */
lp = (uint32 *)wp; lp = (uint32 *)wp;
const uint32 patchCodeOffset = 0x1d3e; // we steal P_mRamTest routine space // we steal P_mRamTest routine space
const uint32 patchCodeOffset = 0x1d3e;
patchCodeBaseMac = ROMBaseMac + patchCodeOffset; patchCodeBaseMac = ROMBaseMac + patchCodeOffset;
uint8* patchCodeBaseHost = ROMBaseHost + patchCodeOffset; uint8* patchCodeBaseHost = ROMBaseHost + patchCodeOffset;
*lp++ = htonl(patchCodeBaseMac); // we JSR to this Mac address // we JSR to this Mac address
*lp++ = htonl(patchCodeBaseMac);
wp = (uint16 *)lp; wp = (uint16 *)lp;
patchwp = (uint16 *)(patchCodeBaseHost); // the host address for the patch // the host address for the patch
patchwp = (uint16 *)(patchCodeBaseHost);
// MOVE.L $MacFrameBaseMac24Bit, ($ScrnBase) // MOVE.L $MacFrameBaseMac24Bit, ($ScrnBase)
*patchwp++ = htons(0x21fc); /* MOVE.L */ *patchwp++ = htons(0x21fc); /* MOVE.L */
patchCodeBaseMac += 2; patchCodeBaseMac += 2;
@ -1043,7 +1053,8 @@ static bool patch_rom_classic(void)
*patchwp++ = htons(0x4e75); /* RTS */ *patchwp++ = htons(0x4e75); /* RTS */
patchCodeBaseMac += 2; patchCodeBaseMac += 2;
patchlp = (uint32 *)patchwp; // keep in sync // keep in sync
patchlp = (uint32 *)patchwp;
// continue to patch P_mInitVideoGlobal routine // continue to patch P_mInitVideoGlobal routine
wp = (uint16 *)(ROMBaseHost + 0x5d2); wp = (uint16 *)(ROMBaseHost + 0x5d2);
@ -1080,7 +1091,8 @@ static bool patch_rom_classic(void)
wp = (uint16 *)(ROMBaseHost + 0x10b0); wp = (uint16 *)(ROMBaseHost + 0x10b0);
*wp = htons(MacScreenWidth / 8); *wp = htons(MacScreenWidth / 8);
lp = (uint32 *)(ROMBaseHost + 0x10b4); lp = (uint32 *)(ROMBaseHost + 0x10b4);
*lp = htonl(MacScreenWidth * MacScreenHeight / 8);// # of bytes in screen // # of bytes in screen
*lp = htonl(MacScreenWidth * MacScreenHeight / 8);
// sad mac, mac icon // sad mac, mac icon
lp = (uint32 *)(ROMBaseHost + 0x118a); lp = (uint32 *)(ROMBaseHost + 0x118a);
@ -1106,7 +1118,8 @@ static bool patch_rom_classic(void)
// cursor handling // cursor handling
if (MacScreenWidth >= 1024) if (MacScreenWidth >= 1024)
{ {
wp = (uint16 *)(ROMBaseHost + 0x18dfe); // start to patch P_HideCursor routine // start to patch P_HideCursor routine
wp = (uint16 *)(ROMBaseHost + 0x18dfe);
*wp++ = htons(0x4eb9); /* JSR */ *wp++ = htons(0x4eb9); /* JSR */
lp = (uint32 *)wp; lp = (uint32 *)wp;
*lp++ = htonl(patchCodeBaseMac); *lp++ = htonl(patchCodeBaseMac);
@ -1145,7 +1158,8 @@ static bool patch_rom_classic(void)
if (MacScreenWidth >= 1024) if (MacScreenWidth >= 1024)
{ {
wp = (uint16 *)(ROMBaseHost + 0x18ec4); // start to patch P_ShowCursor routine // start to patch P_ShowCursor routine
wp = (uint16 *)(ROMBaseHost + 0x18ec4);
*wp++ = htons(0x4eb9); /* JSR */ *wp++ = htons(0x4eb9); /* JSR */
lp = (uint32 *)wp; lp = (uint32 *)wp;
*lp++ = htonl(patchCodeBaseMac); *lp++ = htonl(patchCodeBaseMac);
@ -1166,7 +1180,8 @@ static bool patch_rom_classic(void)
*patchwp++ = htons(0x4e75); /* RTS */ *patchwp++ = htons(0x4e75); /* RTS */
patchCodeBaseMac += 2; patchCodeBaseMac += 2;
patchlp = (uint32 *)patchwp; // keep in sync // keep in sync
patchlp = (uint32 *)patchwp;
} else } else
{ {
wp = (uint16 *)(ROMBaseHost + 0x18ec4); wp = (uint16 *)(ROMBaseHost + 0x18ec4);