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Linking zero page / direct page sections

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Carl-Henrik Skårstedt 2015-11-07 18:23:57 -08:00
parent 5030d0be15
commit 9cd2ee7cd1
2 changed files with 156 additions and 13 deletions
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34
README.md
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@ -194,7 +194,7 @@ Data:
byte 1,2,3,4
```
Starts a relative section. Relative sections require a name and sections that share the same name will be linked sequentially. The labels will be evaluated at link time.
Starts a relative code section. Relative sections require a name and sections that share the same name will be linked sequentially. The labels will be evaluated at link time.
Sections can be aligned by adding a comma separated argument:
@ -213,6 +213,37 @@ If there is any code or data between the SECTION and ORG directives the ORG dire
The primary purpose of relative sections (sections that are not assembled at a fixed address) is to generate object files (.x65) that can be referenced from a linking source file by using **INCOBJ** and assigned an address at that point using the **LINK** directive. Object files can mix and match relative and fixed address sections and only the relative sections need to be linked using the **LINK** directive.
Sections can be named anything and still be assigned a section type:
```
section Gameplay, Code ; code section named Gameplay, unaligned
...
section GameBinary, Data, $100 ; data section named GameBinary, aligned
...
section Work, Zeropage ; Zeropage or Direct page section
...
section FixedZP, Zeropage
org $a0 ; Make zero page section as a fixed address
```
Section types include:
* Code: binary code
* Data: binary data
* BSS: uninitialized memory, for fixed address projects the
* Zeropage: uninitialized memory restricted to the range $00 - $ff
Additional section directive styles include:
```
SEG segname
SEG.U segname
SEGMENT "segname": segtype
.SEGMENT "segname"
```
For creating relocatable files (OMF) certain sections can not be fixed address.
<a name="xdef">**XDEF**
Used in files assembled to object files to share a label globally. All labels that are not xdef'd are still processed but protected so that other objects can use the same label name without colliding. **XDEF <labelname>** must be specified before the label is defined, such as at the top of the file.
@ -891,6 +922,7 @@ Fish food! Assembler has all important features and switching to make a 6502 pro
* irp (indefinite repeat)
**FIXED**
* Linking of zero page / direct page sections
* Added section types, should cover most intuitive formats (seg.type; segment name; segment "name": type; etc. etc.)
* Changed the data for relocs to better match Apple II GS OMF format which also changes the object file format.
* Added a disassembler (disassembler/x65dsasm.s)

135
x65.cpp
View File

@ -135,6 +135,7 @@ enum StatusCode {
ERROR_SECTION_TARGET_OFFSET_OUT_OF_RANGE,
ERROR_CPU_NOT_SUPPORTED,
ERROR_CANT_APPEND_SECTION_TO_TARGET,
ERROR_ZEROPAGE_SECTION_OUT_OF_RANGE,
STATUSCODE_COUNT
};
@ -196,6 +197,7 @@ const char *aStatusStrings[STATUSCODE_COUNT] = {
"Unexpected target offset for reloc or late evaluation",
"CPU is not supported",
"Can't append sections",
"Zero page / Direct page section out of range",
};
// Assembler directives
@ -1461,6 +1463,7 @@ public:
Section& CurrSection() { return *current_section; }
unsigned char* BuildExport(strref append, int &file_size, int &addr);
int GetExportNames(strref *aNames, int maxNames);
StatusCode LinkZP();
int SectionId() { return int(current_section - &allSections[0]); }
void AddByte(int b) { CurrSection().AddByte(b); }
void AddWord(int w) { CurrSection().AddWord(w); }
@ -1869,11 +1872,11 @@ unsigned char* Asm::BuildExport(strref append, int &file_size, int &addr)
while (!has_relative_section && !has_fixed_section) {
int section_id = 0;
for (std::vector<Section>::iterator i = allSections.begin(); i != allSections.end(); ++i) {
if ((!append && !i->export_append) || append.same_str_case(i->export_append)) {
if (((!append && !i->export_append) || append.same_str_case(i->export_append)) && i->type != ST_ZEROPAGE) {
if (!i->IsMergedSection()) {
if (i->IsRelativeSection())
has_relative_section = true;
else if (i->start_address >= 0x200 && i->size() > 0) {
else if (i->start_address >= 0x100 && i->size() > 0) {
has_fixed_section = true;
if (i->start_address < start_address)
start_address = i->start_address;
@ -1896,7 +1899,7 @@ unsigned char* Asm::BuildExport(strref append, int &file_size, int &addr)
last_fixed_section = SectionId();
}
for (std::vector<Section>::iterator i = allSections.begin(); i != allSections.end(); ++i) {
if ((!append && !i->export_append) || append.same_str_case(i->export_append)) {
if (((!append && !i->export_append) || append.same_str_case(i->export_append)) && i->type != ST_ZEROPAGE) {
if (i->IsRelativeSection()) {
StatusCode status = AppendSection(*i, allSections[last_fixed_section]);
if (status != STATUS_OK)
@ -1952,6 +1955,96 @@ int Asm::GetExportNames(strref *aNames, int maxNames)
return count;
}
// Collect all unassigned ZP sections and link them
StatusCode Asm::LinkZP()
{
unsigned char min_addr = 0xff, max_addr = 0x00;
int num_addr = 0;
bool has_assigned = false, has_unassigned = false;
int first_unassigned = -1;
// determine if any zeropage section has been asseigned
for (std::vector<Section>::iterator s = allSections.begin(); s != allSections.end(); ++s) {
if (s->type == ST_ZEROPAGE && !s->IsMergedSection()) {
if (s->address_assigned) {
has_assigned = true;
if (s->start_address < min_addr)
min_addr = s->start_address;
else if (s->address > max_addr)
max_addr = s->address;
} else {
has_unassigned = true;
first_unassigned = first_unassigned >=0 ? first_unassigned : (int)(&*s - &allSections[0]);
}
num_addr += s->address - s->start_address;
}
}
if (num_addr > 0x100)
return ERROR_ZEROPAGE_SECTION_OUT_OF_RANGE;
// no unassigned zp section, nothing to fix
if (!has_unassigned)
return STATUS_OK;
// no section assigned => fit together at end
if (!has_assigned) {
int address = 0x100 - num_addr;
for (std::vector<Section>::iterator s = allSections.begin(); s != allSections.end(); ++s) {
if (s->type == ST_ZEROPAGE && !s->IsMergedSection()) {
s->start_address = address;
s->address += address;
s->address_assigned = true;
int section_id = (int)(&*s - &allSections[0]);
LinkLabelsToAddress(section_id, s->start_address);
StatusCode ret = LinkRelocs(section_id, s->start_address);
if (ret >= FIRST_ERROR)
return ret;
address += s->address - s->start_address;
}
}
} else { // find first fit neighbouring an address assigned zero page section
for (std::vector<Section>::iterator s = allSections.begin(); s != allSections.end(); ++s) {
if (s->type == ST_ZEROPAGE && !s->IsMergedSection() && !s->address_assigned) {
int size = s->address - s->start_address;
bool found = false;
// find any assigned address section and try to place before or after
for (std::vector<Section>::iterator sa = allSections.begin(); sa != allSections.end(); ++sa) {
if (sa->type == ST_ZEROPAGE && !sa->IsMergedSection() && sa->address_assigned) {
for (int e = 0; e < 2; ++e) {
int start = e ? sa->start_address - size : sa->address;
int end = start + size;
if (start >= 0 && end <= 0x100) {
for (std::vector<Section>::iterator sc = allSections.begin(); !found && sc != allSections.end(); ++sc) {
found = true;
if (&*sa != &*sc && sc->type == ST_ZEROPAGE && !sc->IsMergedSection() && sc->address_assigned) {
if (start <= sc->address && sc->start_address <= end)
found = false;
}
}
}
if (found) {
s->start_address = start;
s->address += end;
s->address_assigned = true;
int section_id = (int)(&*s - &allSections[0]);
LinkLabelsToAddress(section_id, s->start_address);
StatusCode ret = LinkRelocs(section_id, s->start_address);
if (ret >= FIRST_ERROR)
return ret;
}
}
}
}
if (!found)
return ERROR_ZEROPAGE_SECTION_OUT_OF_RANGE;
}
}
}
return STATUS_OK;
}
// Apply labels assigned to addresses in a relative section a fixed address
void Asm::LinkLabelsToAddress(int section_id, int section_address)
{
@ -2086,9 +2179,12 @@ StatusCode Asm::LinkSections(strref name) {
for (std::vector<Section>::iterator i = allSections.begin(); i != allSections.end(); ++i) {
if ((!name || i->name.same_str_case(name)) && i->IsRelativeSection() && !i->IsMergedSection()) {
StatusCode status = AppendSection(*i, CurrSection());
if (status != STATUS_OK)
return status;
// Zero page sections can only be linked with zero page sections
if (i->type != ST_ZEROPAGE || CurrSection().type == ST_ZEROPAGE) {
StatusCode status = AppendSection(*i, CurrSection());
if (status != STATUS_OK)
return status;
}
}
}
return STATUS_OK;
@ -2097,6 +2193,8 @@ StatusCode Asm::LinkSections(strref name) {
// Section based output capacity
// Make sure there is room to assemble in
void Section::CheckOutputCapacity(unsigned int addSize) {
if (dummySection || type == ST_ZEROPAGE || type == ST_BSS)
return;
size_t currSize = curr - output;
if ((addSize + currSize) >= output_capacity) {
size_t newSize = currSize * 2;
@ -2114,7 +2212,7 @@ void Section::CheckOutputCapacity(unsigned int addSize) {
// Add one byte to a section
void Section::AddByte(int b) {
if (!dummySection) {
if (!dummySection && type != ST_ZEROPAGE && type != ST_BSS) {
CheckOutputCapacity(1);
*curr++ = (unsigned char)b;
}
@ -2123,7 +2221,7 @@ void Section::AddByte(int b) {
// Add a 16 bit word to a section
void Section::AddWord(int w) {
if (!dummySection) {
if (!dummySection && type != ST_ZEROPAGE && type != ST_BSS) {
CheckOutputCapacity(2);
*curr++ = (unsigned char)(w&0xff);
*curr++ = (unsigned char)(w>>8);
@ -2133,7 +2231,7 @@ void Section::AddWord(int w) {
// Add a 24 bit word to a section
void Section::AddTriple(int l) {
if (!dummySection) {
if (!dummySection && type != ST_ZEROPAGE && type != ST_BSS) {
CheckOutputCapacity(3);
*curr++ = (unsigned char)(l&0xff);
*curr++ = (unsigned char)(l>>8);
@ -2143,7 +2241,7 @@ void Section::AddTriple(int l) {
}
// Add arbitrary length data to a section
void Section::AddBin(unsigned const char *p, int size) {
if (!dummySection) {
if (!dummySection && type != ST_ZEROPAGE && type != ST_BSS) {
CheckOutputCapacity(size);
memcpy(curr, p, size);
curr += size;
@ -3974,6 +4072,8 @@ StatusCode Asm::Directive_ORG(strref line)
// Section immediately followed by ORG reassigns that section to be fixed
if (CurrSection().size()==0 && !CurrSection().IsDummySection()) {
if (CurrSection().type == ST_ZEROPAGE && addr >= 0x100)
return ERROR_ZEROPAGE_SECTION_OUT_OF_RANGE;
CurrSection().start_address = addr;
CurrSection().load_address = addr;
CurrSection().address = addr;
@ -4506,8 +4606,11 @@ StatusCode Asm::ApplyDirective(AssemblerDirective dir, strref line, strref sourc
if (value > 0) {
for (int n = 0; n < value; n++)
AddByte(fill);
} else if (value)
} else if (value) {
CurrSection().AddAddress(value);
if (CurrSection().type == ST_ZEROPAGE && CurrSection().address > 0x100)
return ERROR_ZEROPAGE_SECTION_OUT_OF_RANGE;
}
break;
}
}
@ -4650,7 +4753,8 @@ StatusCode Asm::AddOpcode(strref line, int index, strref source_file)
}
// check if address is in zero page range and should use a ZP mode instead of absolute
if (!evalLater && value>=0 && value<0x100 && error != STATUS_RELATIVE_SECTION) {
if (!evalLater && value>=0 && value<0x100 && (error != STATUS_RELATIVE_SECTION ||
(target_section>=0 && allSections[target_section].type==ST_ZEROPAGE))) {
switch (addrMode) {
case AMB_ABS:
if (validModes & AMM_ZP)
@ -5026,6 +5130,8 @@ StatusCode Asm::BuildLine(strref line)
if (line.same_str_case(line_start))
error = ERROR_UNABLE_TO_PROCESS;
else if (CurrSection().type == ST_ZEROPAGE && CurrSection().address > 0x100)
error = ERROR_ZEROPAGE_SECTION_OUT_OF_RANGE;
if (error > STATUS_XREF_DEPENDENT)
PrintError(line_start, error);
@ -5939,6 +6045,11 @@ int main(int argc, char **argv)
if (ext)
binout.clip(ext.get_len() + 1);
strref aAppendNames[MAX_EXPORT_FILES];
StatusCode err = assembler.LinkZP(); // link zero page sections
if (err > FIRST_ERROR) {
assembler.PrintError(strref(), err);
return_value = 1;
}
int numExportFiles = assembler.GetExportNames(aAppendNames, MAX_EXPORT_FILES);
for (int e = 0; e < numExportFiles; e++) {
strown<512> file(binout);