From 00fc82f17cff9295387d516384ecdc443acb1b22 Mon Sep 17 00:00:00 2001 From: Bradley Morgan Date: Sat, 3 Oct 2026 18:57:38 +0000 Subject: tashaboot: arm64 bringup, semihosting payload loader consoles on the pl011 the dtb points at, walks the memory node and chosen, loads an arm64 kernel Image over semihosting and jumps to it with the documented register state. string functions, printf and libfdt are vendored from lk (lk2nd) and u-boot so the libc surface is the one those projects already proved. built and booted on qemu virt, payload exits clean through semihosting. --- include/semihosting.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 include/semihosting.h (limited to 'include/semihosting.h') diff --git a/include/semihosting.h b/include/semihosting.h new file mode 100644 index 0000000..2f8c8f2 --- /dev/null +++ b/include/semihosting.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __SEMIHOSTING_H +#define __SEMIHOSTING_H + +#include + +/* + * semihosting file io, backed by the host when qemu runs with + * -semihosting. all calls return negative errno style errors so the + * boot flow can fall back to whatever the board has without semihosting. + */ + +enum smh_open_mode { + MODE_READ = 0x0, + MODE_BINARY = 0x1, + MODE_PLUS = 0x2, + MODE_WRITE = 0x4, + MODE_APPEND = 0x8, +}; + +long smh_open(const char *fname, enum smh_open_mode mode); +long smh_read(long fd, void *memp, size_t len); +long smh_write(long fd, const void *memp, size_t len, size_t *written); +long smh_close(long fd); +long smh_flen(long fd); +long smh_seek(long fd, long pos); + +/* probe once, a boot without a debugger attached must not trap */ +bool smh_probe(void); + +#endif -- cgit v1.2.3