No luck. It had the same error message, redeclaration of the variable. Here's
the whole code for context. The other templates may be affecting the outcome of
the one I quoted previously in this discussion. Solving this isn't critical. I
have a working implementation in Nim. I am trying for an optimization in
assembly in part to make my library efficient and also in part to learn how and
when to best use asm in conjunction with Nim.
# main_8.nim
#
# Try to allow this chained rmw construction:
# RCC.AHB1ENR.GPIOAEN(1).write()
import std/bitops
import std/volatile
type
RegisterAddr = uint32
RegisterVal = uint32
# RCC peripheral
type RCC_Base = distinct RegisterAddr
const RCC* = RCC_Base(0x40023800)
# RCC.AHB1ENR register
type RCC_AHB1ENR_Val* = distinct RegisterVal
type RCC_AHB1ENR_Ptr = ptr RCC_AHB1ENR_Val
const RCC_AHB1ENR_Offset = 0x30'u32
const RCC_AHB1ENR = cast[RCC_AHB1ENR_Ptr](RCC.uint32 + RCC_AHB1ENR_Offset)
# reg read
template AHB1ENR*(base: static RCC_Base): RCC_AHB1ENR_Val =
volatileLoad(RCC_AHB1ENR)
# chained field modify
template GPIOAEN*(regVal: RCC_AHB1ENR_Val, fieldVal: uint32):
RCC_AHB1ENR_Val {.dirty.} =
{.emit: ["asm (\"BFI %0, %1, #0, #1\"\n\t: \"=r\" (", regVal, ")\n\t:
\"r\" (", fieldVal, "));\n"].}
regVal
# write the modified fields to the reg
template write*(regVal: RCC_AHB1ENR_Val) =
volatileStore(RCC_AHB1ENR, regVal)
proc main() =
RCC.AHB1ENR # reg read
.GPIOAEN(1'u32) # field modify
.write() # reg write
when isMainModule:
main()
Run
