snark13
c71e249a4e
First substantive commit: the entire Sprinter C compiler tree on top of
the bare README+gitignore initial commit.
What's in here:
bin/sprinter-cc — driver script invoking SDCC + linker + mkexe
libc/ — Sprinter-specific libc layer over ESTEX/BIOS
(conio, gfx, io, mem, stdio + headers)
runtime/ — crt0 variants (default/small/banked/minimal)
+ heap + bank trampolines
toolchain/ — mkexe (SprintEXE packer, C + tests)
examples/ — 30 demo programs (gfx, file I/O, env, time, …)
lib/Makefile — builds the libc archive (sprinter.lib)
docs/ — converted Sprinter manuals + asm reference samples
third_party/ — solid-c reference compiler dump + sdcc setup script
release_docs/ — packaging / release notes
gitignore overhaul:
• Drop dangerous blanket patterns: *.asm (would hide docs/samples/*.asm)
and *.exe (case-insensitive match was hiding third_party/solid-c/*.EXE
on macOS APFS). Replaced with examples/*/*.{asm,exe,…} and lib/*.lib.
• Restore tracking of toolchain/mkexe/tests/{one,big}.bin — those are
INPUT fixtures, not build outputs.
• Collapse the duplicated SDCC/C/Sdcc sections into one section per
concern (build outputs / vendored / OS-junk).
• Add .sprinter-cc-*/, build/ (catches lib/build/ too), .claude/.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
130 lines
4.5 KiB
Plaintext
130 lines
4.5 KiB
Plaintext
4.3 FORMAT OF LINK COMPATIBLE OBJECT FILES
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NOTE
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Section 4.3 is interesting
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material for users who wish to
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know the load format of LINK-80
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relocatable object files. Most
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users will want to skip this
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section, as it does not contain
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material neccessary to the
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operation of the package.
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LINK-compatible object files consist of a bit stream. Individual fields
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within the bit stream are not aligned on byte boundaries, except as
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noted below. Use of a bit stream for relocatable object files keeps the
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size of object files to a minimum, thereby decreasing the number of
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disk reads/writes.
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There are two basic types of load items: Absolute and Relocatable. The
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first bit of an item indicates one of these two types. If the first bit
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is a 0, the following 8 bits are loaded as an absolute byte. If the
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first bit is a 1, the next 2 bits are used to indicate one of four
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types of relocatable items:
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00 Special LINK item (see below).
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01 Program Relative. Load the following 16 bits
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after adding the current Program base.
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10 Data Relative. Load the following 16 bits after
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adding the current Data base.
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11 Common relative. Load the following 16 bits
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after adding the current Common base.
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Special LINK items consist of the bit stream 100 followed by:
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a four-bit control field
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an optional A field consisting of a two-bit address type
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that is the same as the two-bit field above except 00
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specifies absolute address
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an optional B field consisting of 3 bits that give a
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symbol length and up to 8 bits for each character of the
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symbol
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A general representation of a special LINK item is:
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1 00 xxxx yy nn zzz + characters of symbol name
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-------- ---------------------------------
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A field B field
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xxxx Fout-bit control field (0-15 below)
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yy Two-bit address type field
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nn Sixteen-bit value
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zzz Three-bit symbol length field
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The following special types have a B-field only:
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0 Entry symbol (name for search)
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1 Select COMMON block
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2 Program name
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3 Request library search
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4 Extension LINK items (see below)
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The following special LINK items have both an A field and a B field:
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5 Define COMMON size
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6 Chain external (A is head of address chain, B is name of
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external symbol)
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7 Define entry point (A is address, B is name)
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The following special LINK items have an A field only:
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8 External - offset. Used for JMP and CALL to externals
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9 External + offset. The A value will be added to the two
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bytes starting at the current location counter
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immediately before execution.
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10 Define size of Data area (A is size)
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11 Set loading location counter to A
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12 Chain address. A is head of chain, replace all entries
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in chain with current location counter. The last entry
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in the chain has an address field of absolute zero
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13 Define program size (A is size)
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14 End program (forces to byte boundary)
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The following special LINK item has neither an A nor a B field:
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15 End file
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An Extension LINK item follows the general format of a B-field-only
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special LINK item, but contents of the B-field are not a symbol name.
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Instead, the symbol area contains one character to identify the type of
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Extension LINK item, followed by from 1 to 7 characters of additional
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information.
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Thus, every Extension LINK item has the format:
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1 00 0100 zzz i jjjjjjjj
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where
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zzz may be any three bit integer (with 000 representing 8),
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i is an eight bit Extension LINK item type indentifier,
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and
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jjjjjjjj are zzz-1 eight bit character of information whose
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significance depends on i
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At present, there is only one Extension LINK item:
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i = X'35' COBOL overlay segment sentinel
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zzz = 010 (binary)
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j = COBOL segment number -49 (decimal)
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When the overlay segment sentinal is encountered by the linker,
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the current overlay segment number is set to the value of j+49. If
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the previously existing segment number was non-zero and a /N
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switch is in effect, the data area is written to disk in a file
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whose name is the current program name and whose extension is Vnn,
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where nn are the two hexadecimal digits representing the number
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j+49 (decimal).
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