FreeCalypso > hg > freecalypso-tools
view target-utils/libload/amdflash.c @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 11 Feb 2019 00:00:19 +0000 |
parents | e7502631a0f9 |
children |
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/* * This module implements the AMFB and AMFW commands for programming * AMD-style flash memories. Syntax: * * AMFB <baseaddr> -- sets the base address for subsequent AMFW commands * AMFW <offset> <hexstring> -- the actual flash write operation * * The flash memory is assumed to be 16 bits wide. The hex string * argument to the AMFW command is just data, with no header, address, * length, checksum or other additions. The number of hex digits in the * string must be a multiple of 4, and the byte order is the same as * that of TI's *.m0 files: we interpret the string as consisting of * 16-bit words rather than bytes. * * The address to which each flash write is directed is the sum of the * base given to AMFB and the offset given to AMFW. The fixed offsets * of 0xAAA and 0x554 (0x555 and 0x2AA in words) prescribed for the flash * programming command sequence are also made from the base set with AMFB. */ #include <sys/types.h> #include "types.h" static u32 base_addr; void cmd_AMFB(argbulk) char *argbulk; { char *argv[2]; u_long addr; if (parse_args(argbulk, 1, 1, argv, 0) < 0) return; if (parse_hexarg(argv[0], 8, &addr) < 0) { printf("ERROR: argument must be a valid 32-bit hex address\n"); return; } if (addr & 1) { printf("ERROR: odd address\n"); return; } base_addr = addr; } void cmd_AMFW(argbulk) char *argbulk; { char *argv[3], *s; u_long offset; volatile u16 *flashptr; u32 datum; /* needs to be u32 for decode_hex_digits() */ int i; if (parse_args(argbulk, 2, 2, argv, 0) < 0) return; if (parse_hexarg(argv[0], 8, &offset) < 0) { printf("ERROR: offset argument must a valid 32-bit hex value\n"); return; } if (offset & 1) { printf("ERROR: odd offset argument\n"); return; } flashptr = (volatile u16 *)(base_addr + offset); for (s = argv[1]; *s; flashptr++, s += 4) { if (decode_hex_digits(s, 4, &datum) < 0) { printf("ERROR: bad AMFW hex string argument\n"); return; } if (*flashptr != 0xFFFF) { printf("ERROR: flash not blank at %08X\n", (u_long) flashptr); return; } *(volatile u16 *)(base_addr + 0xAAA) = 0xAA; *(volatile u16 *)(base_addr + 0x554) = 0x55; *(volatile u16 *)(base_addr + 0xAAA) = 0xA0; *flashptr = datum; for (i = 10000; i; i--) if (*flashptr == datum) break; if (!i) { printf("ERROR: flash write timeout at %08X\n", (u_long) flashptr); return; } } }