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Scramble banks from the end of the ROM (#1273)

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This is more likely to test edge cases, such as having content in banks with their highest bit set.
This commit is contained in:
Rangi
2023-12-17 20:14:03 -05:00
committed by GitHub
parent 5a3a215b0e
commit 39018174c5
5 changed files with 61 additions and 23 deletions
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64
src/link/assign.cpp
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@@ -114,25 +114,25 @@ static bool isLocationSuitable(struct Section const *section,
static struct FreeSpace *getPlacement(struct Section const *section,
struct MemoryLocation *location)
{
static uint16_t curScrambleROM = 1;
static uint8_t curScrambleWRAM = 1;
static uint8_t curScrambleSRAM = 1;
static uint16_t curScrambleROM = 0;
static uint8_t curScrambleWRAM = 0;
static int8_t curScrambleSRAM = 0;
// Determine which bank we should start searching in
if (section->isBankFixed) {
location->bank = section->bank;
} else if (scrambleROMX && section->type == SECTTYPE_ROMX) {
location->bank = curScrambleROM++;
if (curScrambleROM > scrambleROMX)
curScrambleROM = 1;
if (curScrambleROM < 1)
curScrambleROM = scrambleROMX;
location->bank = curScrambleROM--;
} else if (scrambleWRAMX && section->type == SECTTYPE_WRAMX) {
location->bank = curScrambleWRAM++;
if (curScrambleWRAM > scrambleWRAMX)
curScrambleWRAM = 1;
if (curScrambleWRAM < 1)
curScrambleWRAM = scrambleWRAMX;
location->bank = curScrambleWRAM--;
} else if (scrambleSRAM && section->type == SECTTYPE_SRAM) {
location->bank = curScrambleSRAM++;
if (curScrambleSRAM > scrambleSRAM)
curScrambleSRAM = 0;
if (curScrambleSRAM < 0)
curScrambleSRAM = scrambleSRAM;
location->bank = curScrambleSRAM--;
} else {
location->bank = sectionTypeInfo[section->type].firstBank;
}
@@ -168,8 +168,7 @@ static struct FreeSpace *getPlacement(struct Section const *section,
// Ensure we're there (e.g. on first check)
location->address &= ~section->alignMask;
// Go to next align boundary and add offset
location->address += section->alignMask + 1
+ section->alignOfs;
location->address += section->alignMask + 1 + section->alignOfs;
} else {
// Any location is fine, so, next free block
space = space->next;
@@ -179,20 +178,43 @@ static struct FreeSpace *getPlacement(struct Section const *section,
// If that location is past the current block's end,
// go forwards until that is no longer the case.
while (space && location->address >=
space->address + space->size)
while (space && location->address >= space->address + space->size)
space = space->next;
// Try again with the new location/free space combo
}
if (section->isBankFixed)
// Try again in the next bank, if one is available.
// Try scrambled banks in descending order until no bank in the scrambled range is available.
// Otherwise, try in ascending order.
if (section->isBankFixed) {
return NULL;
// Try again in the next bank
location->bank++;
if (location->bank > sectionTypeInfo[section->type].lastBank)
} else if (scrambleROMX && section->type == SECTTYPE_ROMX && location->bank <= scrambleROMX) {
if (location->bank > sectionTypeInfo[section->type].firstBank)
location->bank--;
else if (scrambleROMX < sectionTypeInfo[section->type].lastBank)
location->bank = scrambleROMX + 1;
else
return NULL;
} else if (scrambleWRAMX && section->type == SECTTYPE_WRAMX && location->bank <= scrambleWRAMX) {
if (location->bank > sectionTypeInfo[section->type].firstBank)
location->bank--;
else if (scrambleWRAMX < sectionTypeInfo[section->type].lastBank)
location->bank = scrambleWRAMX + 1;
else
return NULL;
} else if (scrambleSRAM && section->type == SECTTYPE_SRAM && location->bank <= scrambleSRAM) {
if (location->bank > sectionTypeInfo[section->type].firstBank)
location->bank--;
else if (scrambleSRAM < sectionTypeInfo[section->type].lastBank)
location->bank = scrambleSRAM + 1;
else
return NULL;
} else if (location->bank < sectionTypeInfo[section->type].lastBank) {
location->bank++;
} else {
return NULL;
}
#undef BANK_INDEX
}
}