pdfpages rotate odd pages 180º

Here is a suggestion using a file step1.tex as intermediate file.

\documentclass[landscape]{article}
\usepackage{pgffor}
\usepackage{etoolbox}
\usepackage{pdfpages}

\usepackage{filecontents}
\begin{filecontents*}{\jobname-step1.tex}
\documentclass[a4paper,landscape]{article}
\usepackage{pdfpages}
\begin{document}
    \includepdf[nup=2x1,pages=-,booklet,noautoscale,frame]{phi.pdf}
\end{document}
\end{filecontents*}

\immediate\write18{pdflatex \jobname-step1}% compiles \jobname-step1.tex

\begin{document}
\pdfximage{\jobname-step1.pdf}% counts pages in \jobname-step1.pdf
\foreach \p in {1,...,\the\pdflastximagepages}{%
  \ifnumodd{\p}%
    {\includepdf[pages=\p,angle=180]{\jobname-step1}}%
    {\includepdf[pages=\p]{\jobname-step1}}%
}
\end{document}

Note that pdflatex --shell-escape is needed. Or you have to comment the line \immediate... and compile the file \jobname-step1 separatly.