Low-level JTAG primitives operating directly on jc->io_functions
(single-device chain assumed), independent of jtag_core:
- bscan_set_ir
- bscan_shift_dr (TDI/TDO, LSB-first packing)
- bscan_idle_cycles
High-level operations driven by an fpga_target descriptor:
- bscan_load_bitstream: JPROGRAM -> CFG_IN -> shift (bit-reversed for
Xilinx) -> JSTART -> idle -> BYPASS
- bscan_load_bitstream_file: parses the Xilinx .bit container header
(sections a/b/c/d/e), falls back to raw .bin
bscan_spi_xfer is stubbed: the quartiq jtagspi protocol details will
be wired once we have a proxy .bit to validate against (OpenOCD
src/flash/nor/jtagspi.c is the host-side reference).
Three new script commands:
- bscan_set_ir <opcode_hex> <ir_length>
- bscan_shift_dr <nbits> (writes zeros, prints captured TDO)
- bscan_load_bitstream <device> <path>
The sanity check for a healthy primitive on KU15P:
jtag_init_scan; bscan_set_ir 9 6; bscan_shift_dr 32 -> 04 A5 60 93
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
modules/fpga/ holds an fpga_target struct (IDCODE/mask, family, IR
length and private opcodes, proxy bitstream path, quirks) and a
compile-time registry. Initial entry: Xilinx Kintex UltraScale+
XCKU15P, populated from bsdl_files/xcku15p_ffve1517.bsd (IDCODE
0x04A56093, IR 6, USER1=0x02, CFG_IN=0x05, JPROGRAM=0x0B, JSTART=0x0C,
JSHUTDOWN=0x0D, ISC_DISABLE=0x16, quirk CCLK_VIA_STARTUP).
Two new script commands:
- fpga_list: enumerate the registry
- fpga_info: match each device on the JTAG chain against the registry
and surface known quirks
Adding another FPGA = one entry in fpga_registry[] + its .bsd in
bsdl_files/. Proxy .bit will be wired in phase 2.5 (bscan_spi/).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Durable project context (architecture, roadmap, key decisions, external
references, commit conventions) so any Claude Code session on any
machine has the same baseline understanding. Machine-local facts stay
out of the repo, in ~/.claude/.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
