ref: 152159a8297a7595b4455c03361851d354288177
dir: /sys/src/9/teg2/words/
this is a plan 9 port to the Trimslice with tegra2 soc: dual-core, dual-issue 1GHz Cortex-A9 system (v7a arch). dram is 1GB at 0. linux believes that u-boot runs in the bottom 4MB. the l2 cache is a non-architectural bag nailed on the side. mp arm systems have a generic interrupt controller; this one is gic v1(!). vfp 3 floating-point is present. section numbers (§) are in the tegra 2 tech. ref. man. for a minimal cpu server, need these devices to work: clock signals §5 (leave to u-boot), pad mux + gpio crap §8, §11 and §18 (leave to u-boot), ☑ 1 cpu §13, ☑ uart (16[45]50) §22, ☑ gic (gic.v1.pdf), ☑ clock §6—7, ☑ ether8169 via pcie §31. then add these: ☑ 2nd cpu (cortex.a9.mpcore.pdf), ☑ l2 cache (l2cache.pl310.pdf, errata), ☑ fpu (cortex.a9.fp.pdf), ☑ user profiling, kprof, in-line 64-bit arithmetic, eventually might want: usb (e.g., for sata) §26, nor flash §17, video §29, and the really horrid ones: nand flash §16, mmc §25. physical memory map 0 1GB ram 40000000 256K iram (audio/video memory) 50000000 cortex-a9 cpu regs, periphbase, intr distrib, memsel, l2 cache 54000000 graphics regs 58000000 gart (graphics window) 60000000 256MB ppsb bus dev regs, including semas, intr ctlr, dma, arm7 cache, gpio, except. vects 70000000 256MB apc bus regs, including uarts, nand, nor, spi, rtc 80000000 1GB ahb extern mem, pcie for cpu only 90000000-97ffffff pcie 0 mem(?) a0000000-a7ffffff pcie 0 prefetch mem, includes rtl8111dl ether(?) a0020000 ether region 4 a0024000 ether region 2 c0000000 256MB ahb bus virtual b0000000 c3000000-c80007ff 81MB ide, usb, sata, mmc d0000000 256MB nor flash virtual 40000000 f000f000 4K mmu tlb fff00000 48K irom boot code ffff0000 64K high vectors use 0xc0000000 as KZERO.