xv6/data.S
2011-02-19 21:17:55 -05:00

26 lines
796 B
ArmAsm

// The kernel layout is:
//
// text
// rodata
// data
// bss
//
// Conventionally, Unix linkers provide pseudo-symbols
// etext, edata, and end, at the end of the text, data, and bss.
// For the kernel mapping, we need the address at the beginning
// of the data section, but that's not one of the conventional
// symbols, because the convention started before there was a
// read-only rodata section between text and data.
//
// To get the address of the data section, we define a symbol
// named data and make sure this is the first object passed to
// the linker, so that it will be the first symbol in the data section.
//
// Alternative approaches would be to parse our own ELF header
// or to write a linker script, but this is simplest.
.data
.globl data
data:
.word 1