From 572849ec2af20416c118248b0ce95d4bb70929be Mon Sep 17 00:00:00 2001
From: Stefan Rueger <stefan.rueger@urclocks.com>
Date: Thu, 21 Jul 2022 21:42:07 +0100
Subject: [PATCH] Provide avr_set_addr_mem() to set addresses in SPI opcodes
within boundaries
The function avr_set_addr_mem(AVRMEM *mem, int opnum, unsigned char *cmd,
unsigned long addr) is meant to replace avr_set_addr(OPCODE *op, unsigned
char *cmd, unsigned long addr) in future.
avr_set_addr_mem() has more information about the context of the task in that
it knows the memory size, memory page size, whether or not the memory is a
flash memory (which gets words addressees supplied) and, crucially, knows
which SPI operation it is meant to compute the address bits for.
avr_set_addr_mem() first computes the interval of bit numbers that must be
supplied for the SPI command to stand a chance to work. The function only
sets those address bits that are needed. Once all avr_set_addr() function
calls have been replaced by avr_set_addr_mem(), the SPI commands that need an
address can afford to declare in avrdude.conf all 16 address bits in the
middle two bytes of the SPI command. This over-declaration will be corrected
during runtime by avr_set_addr_mem(). One consequence of this is that parts
can inherit smaller or larger memories from parents without the need to use
different SPI codes in avrdude.conf. Another consequence is that
avr_set_addr_mem() can, and does, tell the caller whether vital address bits
were not declared in the SPI opcode. During parsing of avrdude.conf this
might be utilised to generate a corresponding warning. This will uncover
problematic SPI codes in avrdude.conf that in the past went undetected.
---
src/developer_opts.c | 94 ++++++++++++++++++++++++++++++++++++++++++++
src/developer_opts.h | 1 +
2 files changed, 95 insertions(+)
diff --git a/src/developer_opts.c b/src/developer_opts.c
index cdc40a21..2f50eda6 100644
--- a/src/developer_opts.c
+++ b/src/developer_opts.c
@@ -295,6 +295,100 @@ static void checkaddr(int memsize, int pagesize, int opnum, OPCODE *op, AVRPART
}
+/*
+ * avr_set_addr_mem()
+ *
+ * Set address bits in the specified command based on the memory, opcode and
+ * address; addr must be a word address for flash or, for all other memories,
+ * a byte address; returns 0 on success and -1 on error (no memory or no
+ * opcode) or, if positive, bn+1 where bn is bit number of the highest
+ * necessary bit that the opcode does not provide.
+ */
+int avr_set_addr_mem(AVRMEM *mem, int opnum, unsigned char *cmd, unsigned long addr) {
+ int ret, isflash, lo, hi, memsize, pagesize;
+ OPCODE *op;
+
+ if(!mem)
+ return -1;
+
+ if(!(op = mem->op[opnum]))
+ return -1;
+
+ isflash = !strcmp(mem->desc, "flash"); // ISP parts have only one flash-like memory
+ memsize = mem->size >> isflash; // word addresses for flash
+ pagesize = mem->page_size >> isflash;
+
+ // compute range lo..hi of needed address bits
+ switch(opnum) {
+ case AVR_OP_READ:
+ case AVR_OP_WRITE:
+ case AVR_OP_READ_LO:
+ case AVR_OP_READ_HI:
+ case AVR_OP_WRITE_LO:
+ case AVR_OP_WRITE_HI:
+ lo = 0;
+ hi = intlog2(memsize-1); // memsize = 1 implies no addr bit is needed
+ break;
+
+ case AVR_OP_LOADPAGE_LO:
+ case AVR_OP_LOADPAGE_HI:
+ lo = 0;
+ hi = intlog2(pagesize-1);
+ break;
+
+ case AVR_OP_LOAD_EXT_ADDR:
+ lo = 16;
+ hi = intlog2(memsize-1);
+ break;
+
+ case AVR_OP_WRITEPAGE:
+ lo = intlog2(pagesize);
+ hi = intlog2(memsize-1);
+ break;
+
+ case AVR_OP_CHIP_ERASE:
+ case AVR_OP_PGM_ENABLE:
+ default:
+ lo = 0;
+ hi = -1;
+ break;
+ }
+
+ // Unless it's load extended address, ISP chips only deal with 16 bit addresses
+ if(opnum != AVR_OP_LOAD_EXT_ADDR && hi > 15)
+ hi = 15;
+
+ unsigned char avail[32];
+ memset(avail, 0, sizeof avail);
+
+ for(int i=0; i<32; i++) {
+ if(op->bit[i].type == AVR_CMDBIT_ADDRESS) {
+ int bitno, j, bit;
+ unsigned char mask;
+
+ bitno = op->bit[i].bitno & 31;
+ j = 3 - i / 8;
+ bit = i % 8;
+ mask = 1 << bit;
+ avail[bitno] = 1;
+
+ // 'a' bit with number outside bit range [lo, hi] is set to 0
+ if (bitno >= lo && bitno <= hi? (addr >> bitno) & 1: 0)
+ cmd[j] = cmd[j] | mask;
+ else
+ cmd[j] = cmd[j] & ~mask;
+ }
+ }
+
+ ret = 0;
+ if(lo >= 0 && hi < 32 && lo <= hi)
+ for(int bn=lo; bn <= hi; bn++)
+ if(!avail[bn]) // necessary bit bn misses in opcode
+ ret = bn+1;
+
+ return ret;
+}
+
static char *dev_sprintf(const char *fmt, ...) {
int size = 0;
char *p = NULL;
diff --git a/src/developer_opts.h b/src/developer_opts.h
index 00c13005..d112f517 100644
--- a/src/developer_opts.h
+++ b/src/developer_opts.h
@@ -25,6 +25,7 @@ const char *opcodename(int opnum);
char *opcode2str(OPCODE *op, int opnum, int detailed);
int opcodecmp(OPCODE *op1, OPCODE *op2, int opnum);
int intlog2(unsigned int n);
+int avr_set_addr_mem(AVRMEM *mem, int opnum, unsigned char *cmd, unsigned long addr);
int part_match(const char *pattern, const char *string);
void dev_output_part_defs(char *partdesc);