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Implement floating bank in linker script

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Turns out that we can solve being unable to choose a bank to change
the PC of, by simply refusing to choose!
This commit is contained in:
ISSOtm
2024-08-14 02:16:13 +02:00
committed by Eldred Habert
parent e45a422da3
commit 28733fe312
3 changed files with 58 additions and 15 deletions
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54
src/link/script.y
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@@ -35,6 +35,7 @@
static void includeFile(std::string &&path);
static void incLineNo();
static void setFloatingSectionType(SectionType type);
static void setSectionType(SectionType type);
static void setSectionType(SectionType type, uint32_t bank);
static void setAddr(uint32_t addr);
@@ -106,11 +107,14 @@ line:
directive:
sect_type {
setSectionType($1);
setSectionType($1);
}
| sect_type number {
setSectionType($1, $2);
}
| sect_type FLOATING {
setFloatingSectionType($1);
}
| FLOATING {
makeAddrFloating();
}
@@ -388,6 +392,20 @@ static void setActiveTypeAndIdx(SectionType type, uint32_t idx) {
}
}
static void setFloatingSectionType(SectionType type) {
if (nbbanks(type) == 1) {
setActiveTypeAndIdx(type, 0); // There is only a single bank anyway, so just set the index to 0.
} else {
activeType = type;
activeBankIdx = UINT32_MAX;
// Force PC to be floating for this kind of section.
// Because we wouldn't know how to index into `curAddr[activeType]`!
isPcFloating = true;
floatingAlignMask = 0;
floatingAlignOffset = 0;
}
}
static void setSectionType(SectionType type) {
auto const &context = lexerStack.back();
@@ -433,6 +451,10 @@ static void setAddr(uint32_t addr) {
scriptError(context, "Cannot set the current address: no memory region is active");
return;
}
if (activeBankIdx == UINT32_MAX) {
scriptError(context, "Cannot set the current address: the bank is floating");
return;
}
auto &pc = curAddr[activeType][activeBankIdx];
auto const &typeInfo = sectionTypeInfo[activeType];
@@ -627,20 +649,24 @@ static void placeSection(std::string const &name, bool isOptional) {
);
}
uint32_t bank = activeBankIdx + typeInfo.firstBank;
if (section->isBankFixed && bank != section->bank) {
scriptError(
context,
"The linker script places section \"%s\" in %s bank %" PRIu32
", but it was already defined in bank %" PRIu32,
name.c_str(),
sectionTypeInfo[section->type].name.c_str(),
bank,
section->bank
);
if (activeBankIdx == UINT32_MAX) {
section->isBankFixed = false;
} else {
uint32_t bank = activeBankIdx + typeInfo.firstBank;
if (section->isBankFixed && bank != section->bank) {
scriptError(
context,
"The linker script places section \"%s\" in %s bank %" PRIu32
", but it was already defined in bank %" PRIu32,
name.c_str(),
sectionTypeInfo[section->type].name.c_str(),
bank,
section->bank
);
}
section->isBankFixed = true;
section->bank = bank;
}
section->isBankFixed = true;
section->bank = bank;
if (!isPcFloating) {
uint16_t &org = curAddr[activeType][activeBankIdx];